{"id":47699,"date":"2025-07-30T08:51:48","date_gmt":"2025-07-30T00:51:48","guid":{"rendered":"https:\/\/www.wsisp.com\/helps\/47699.html"},"modified":"2025-07-30T08:51:48","modified_gmt":"2025-07-30T00:51:48","slug":"%e5%9f%ba%e7%a1%8009-java%e9%9d%a2%e5%90%91%e5%af%b9%e8%b1%a1%e7%bc%96%e7%a8%8b%e5%9f%ba%e7%a1%80%ef%bc%9a%e7%90%86%e8%a7%a3%e7%b1%bb%e4%b8%8e%e5%af%b9%e8%b1%a1","status":"publish","type":"post","link":"https:\/\/www.wsisp.com\/helps\/47699.html","title":{"rendered":"\u57fa\u784009-Java\u9762\u5411\u5bf9\u8c61\u7f16\u7a0b\u57fa\u7840\uff1a\u7406\u89e3\u7c7b\u4e0e\u5bf9\u8c61"},"content":{"rendered":"<h2>Java\u9762\u5411\u5bf9\u8c61\u7f16\u7a0b\u57fa\u7840&#xff1a;\u7406\u89e3\u7c7b\u4e0e\u5bf9\u8c61<\/h2>\n<h3>\u5f15\u8a00<\/h3>\n<p>\u5728\u5f53\u4eca\u8f6f\u4ef6\u5f00\u53d1\u7684\u4e16\u754c\u91cc&#xff0c;\u9762\u5411\u5bf9\u8c61\u7f16\u7a0b&#xff08;Object-Oriented Programming, OOP&#xff09;\u5df2\u7ecf\u6210\u4e3a\u6784\u5efa\u590d\u6742\u3001\u53ef\u7ef4\u62a4\u548c\u53ef\u6269\u5c55\u5e94\u7528\u7a0b\u5e8f\u7684\u57fa\u77f3\u3002Java&#xff0c;\u4f5c\u4e3a\u4e00\u95e8\u5386\u53f2\u60a0\u4e45\u4e14\u5e7f\u6cdb\u5e94\u7528\u7684\u7f16\u7a0b\u8bed\u8a00&#xff0c;\u81ea\u8bde\u751f\u4e4b\u521d\u5c31\u6df1\u6df1\u690d\u6839\u4e8e\u9762\u5411\u5bf9\u8c61\u7684\u7406\u5ff5\u4e4b\u4e2d\u3002\u638c\u63e1Java\u7684\u9762\u5411\u5bf9\u8c61\u7f16\u7a0b\u57fa\u7840&#xff0c;\u5c24\u5176\u662f\u5bf9\u201c\u7c7b\u201d\u4e0e\u201c\u5bf9\u8c61\u201d\u8fd9\u4e24\u4e2a\u6838\u5fc3\u6982\u5ff5\u7684\u6df1\u523b\u7406\u89e3&#xff0c;\u662f\u6bcf\u4e00\u4f4dJava\u5f00\u53d1\u8005\u8fc8\u5411\u4e13\u4e1a\u4e4b\u8def\u7684\u5fc5\u7ecf\u95e8\u69db\u3002<\/p>\n<p>\u672c\u7bc7\u535a\u5ba2\u65e8\u5728\u7cfb\u7edf\u3001\u5168\u9762\u5730\u9610\u8ff0Java\u9762\u5411\u5bf9\u8c61\u7f16\u7a0b\u4e2d\u5173\u4e8e\u201c\u7c7b\u201d\u4e0e\u201c\u5bf9\u8c61\u201d\u7684\u57fa\u7840\u77e5\u8bc6\u3002\u6211\u4eec\u5c06\u4ece\u6700\u57fa\u7840\u7684\u6982\u5ff5\u8bb2\u8d77&#xff0c;\u9010\u6b65\u6df1\u5165\u5230\u8bed\u6cd5\u7ec6\u8282\u3001\u8bbe\u8ba1\u539f\u5219\u548c\u5b9e\u9645\u5e94\u7528\u3002\u901a\u8fc7\u5927\u91cf\u7684\u4ee3\u7801\u793a\u4f8b&#xff0c;\u529b\u6c42\u8ba9\u62bd\u8c61\u7684\u6982\u5ff5\u53d8\u5f97\u5177\u4f53\u53ef\u611f&#xff0c;\u5e2e\u52a9\u8bfb\u8005\u4e0d\u4ec5\u201c\u77e5\u9053\u201d\u7c7b\u4e0e\u5bf9\u8c61\u662f\u4ec0\u4e48&#xff0c;\u66f4\u80fd\u201c\u7406\u89e3\u201d\u5b83\u4eec\u5982\u4f55\u5de5\u4f5c&#xff0c;\u4ee5\u53ca\u4e3a\u4f55\u5982\u6b64\u8bbe\u8ba1\u3002\u65e0\u8bba\u4f60\u662f\u521a\u521a\u63a5\u89e6\u7f16\u7a0b\u7684\u65b0\u624b&#xff0c;\u8fd8\u662f\u5e0c\u671b\u5de9\u56fa\u57fa\u7840\u7684\u6709\u7ecf\u9a8c\u5f00\u53d1\u8005&#xff0c;\u76f8\u4fe1\u90fd\u80fd\u4ece\u672c\u6587\u4e2d\u83b7\u5f97\u6709\u4ef7\u503c\u7684\u89c1\u89e3\u3002<\/p>\n<hr \/>\n<h3>\u7b2c\u4e00\u7ae0&#xff1a;\u9762\u5411\u5bf9\u8c61\u7f16\u7a0b\u6982\u8ff0<\/h3>\n<h4>1.1 \u4ec0\u4e48\u662f\u9762\u5411\u5bf9\u8c61\u7f16\u7a0b&#xff1f;<\/h4>\n<p>\u5728\u6df1\u5165Java\u7684\u5177\u4f53\u8bed\u6cd5\u4e4b\u524d&#xff0c;\u6211\u4eec\u9996\u5148\u9700\u8981\u7406\u89e3\u201c\u9762\u5411\u5bf9\u8c61\u201d\u8fd9\u4e00\u7f16\u7a0b\u8303\u5f0f\u7684\u54f2\u5b66\u548c\u6838\u5fc3\u601d\u60f3\u3002<\/p>\n<p>\u9762\u5411\u5bf9\u8c61\u7f16\u7a0b&#xff08;OOP&#xff09; \u662f\u4e00\u79cd\u7f16\u7a0b\u8303\u5f0f&#xff0c;\u5b83\u5c06\u73b0\u5b9e\u4e16\u754c\u4e2d\u7684\u4e8b\u7269\u62bd\u8c61\u4e3a\u7a0b\u5e8f\u4e2d\u7684\u201c\u5bf9\u8c61\u201d&#xff0c;\u5e76\u901a\u8fc7\u5bf9\u8c61\u4e4b\u95f4\u7684\u4ea4\u4e92\u6765\u89e3\u51b3\u95ee\u9898\u3002OOP\u7684\u6838\u5fc3\u601d\u60f3\u662f\u5c06\u6570\u636e&#xff08;\u72b6\u6001&#xff09;\u548c\u64cd\u4f5c\u8fd9\u4e9b\u6570\u636e\u7684\u65b9\u6cd5&#xff08;\u884c\u4e3a&#xff09;\u5c01\u88c5\u5728\u4e00\u8d77&#xff0c;\u5f62\u6210\u4e00\u4e2a\u72ec\u7acb\u7684\u5355\u5143\u2014\u2014\u5bf9\u8c61\u3002<\/p>\n<p>\u4e0e\u4e4b\u76f8\u5bf9\u7684\u662f\u8fc7\u7a0b\u5f0f\u7f16\u7a0b&#xff08;\u5982C\u8bed\u8a00&#xff09;&#xff0c;\u5b83\u66f4\u4fa7\u91cd\u4e8e\u4e00\u7cfb\u5217\u6309\u987a\u5e8f\u6267\u884c\u7684\u51fd\u6570\u6216\u8fc7\u7a0b&#xff0c;\u6570\u636e\u901a\u5e38\u662f\u5168\u5c40\u6216\u5c40\u90e8\u53d8\u91cf&#xff0c;\u4e0e\u64cd\u4f5c\u5b83\u4eec\u7684\u51fd\u6570\u662f\u5206\u79bb\u7684\u3002<\/p>\n<p>OOP\u7684\u4e3b\u8981\u4f18\u52bf\u5728\u4e8e&#xff1a;<\/p>\n<ul>\n<li>\u6a21\u5757\u5316&#xff08;Modularity&#xff09;&#xff1a;\u7a0b\u5e8f\u88ab\u5206\u89e3\u4e3a\u72ec\u7acb\u7684\u3001\u53ef\u7ba1\u7406\u7684\u6a21\u5757&#xff08;\u5bf9\u8c61&#xff09;&#xff0c;\u6bcf\u4e2a\u6a21\u5757\u8d1f\u8d23\u7279\u5b9a\u7684\u529f\u80fd\u3002<\/li>\n<li>\u4fe1\u606f\u9690\u85cf&#xff08;Information Hiding&#xff09;&#xff1a;\u5bf9\u8c61\u7684\u5185\u90e8\u5b9e\u73b0\u7ec6\u8282\u5bf9\u5916\u90e8\u662f\u9690\u85cf\u7684&#xff0c;\u53ea\u80fd\u901a\u8fc7\u5b9a\u4e49\u597d\u7684\u63a5\u53e3\u8fdb\u884c\u8bbf\u95ee&#xff0c;\u8fd9\u63d0\u9ad8\u4e86\u5b89\u5168\u6027\u548c\u964d\u4f4e\u4e86\u590d\u6742\u6027\u3002<\/li>\n<li>\u4ee3\u7801\u91cd\u7528&#xff08;Code Reusability&#xff09;&#xff1a;\u901a\u8fc7\u7ee7\u627f\u548c\u7ec4\u5408&#xff0c;\u53ef\u4ee5\u590d\u7528\u5df2\u6709\u7684\u4ee3\u7801&#xff0c;\u51cf\u5c11\u91cd\u590d\u5f00\u53d1\u3002<\/li>\n<li>\u53ef\u7ef4\u62a4\u6027&#xff08;Maintainability&#xff09;&#xff1a;\u7531\u4e8e\u6a21\u5757\u5316\u548c\u5c01\u88c5&#xff0c;\u4fee\u6539\u4e00\u4e2a\u5bf9\u8c61\u7684\u5185\u90e8\u5b9e\u73b0\u901a\u5e38\u4e0d\u4f1a\u5f71\u54cd\u5230\u5176\u4ed6\u90e8\u5206\u7684\u4ee3\u7801&#xff0c;\u4f7f\u5f97\u7a0b\u5e8f\u66f4\u5bb9\u6613\u7ef4\u62a4\u548c\u5347\u7ea7\u3002<\/li>\n<li>\u53ef\u6269\u5c55\u6027&#xff08;Extensibility&#xff09;&#xff1a;\u901a\u8fc7\u7ee7\u627f\u548c\u591a\u6001&#xff0c;\u53ef\u4ee5\u8f7b\u677e\u5730\u6dfb\u52a0\u65b0\u7684\u529f\u80fd\u800c\u4e0d\u7834\u574f\u73b0\u6709\u4ee3\u7801\u3002<\/li>\n<\/ul>\n<h4>1.2 \u9762\u5411\u5bf9\u8c61\u7684\u56db\u5927\u652f\u67f1<\/h4>\n<p>\u9762\u5411\u5bf9\u8c61\u7f16\u7a0b\u5efa\u7acb\u5728\u56db\u4e2a\u57fa\u672c\u652f\u67f1\u4e4b\u4e0a&#xff0c;\u5b83\u4eec\u5171\u540c\u6784\u6210\u4e86OOP\u7684\u5b8c\u6574\u4f53\u7cfb&#xff1a;<\/p>\n<li>\n<p>\u5c01\u88c5&#xff08;Encapsulation&#xff09;&#xff1a;<\/p>\n<ul>\n<li>\u5b9a\u4e49&#xff1a;\u5c06\u6570\u636e&#xff08;\u5c5e\u6027&#xff09;\u548c\u64cd\u4f5c\u6570\u636e\u7684\u65b9\u6cd5&#xff08;\u884c\u4e3a&#xff09;\u6346\u7ed1\u5728\u4e00\u8d77&#xff0c;\u5f62\u6210\u4e00\u4e2a\u72ec\u7acb\u7684\u5355\u5143&#xff08;\u5373\u5bf9\u8c61&#xff09;&#xff0c;\u5e76\u5c3d\u53ef\u80fd\u9690\u85cf\u5bf9\u8c61\u7684\u5185\u90e8\u5b9e\u73b0\u7ec6\u8282\u3002<\/li>\n<li>\u76ee\u7684&#xff1a;\u63a7\u5236\u5bf9\u5bf9\u8c61\u5185\u90e8\u72b6\u6001\u7684\u8bbf\u95ee&#xff0c;\u9632\u6b62\u5916\u90e8\u4ee3\u7801\u968f\u610f\u4fee\u6539\u6570\u636e&#xff0c;\u786e\u4fdd\u6570\u636e\u7684\u5b8c\u6574\u6027\u548c\u5b89\u5168\u6027\u3002\u901a\u5e38\u901a\u8fc7\u8bbf\u95ee\u4fee\u9970\u7b26&#xff08;\u5982private, public&#xff09;\u6765\u5b9e\u73b0\u3002<\/li>\n<li>\u7c7b\u6bd4&#xff1a;\u5c31\u50cf\u4e00\u4e2a\u7535\u89c6\u673a&#xff0c;\u4f60\u901a\u8fc7\u9065\u63a7\u5668&#xff08;\u63a5\u53e3&#xff09;\u6765\u5f00\u5173\u673a\u3001\u6362\u53f0\u3001\u8c03\u8282\u97f3\u91cf&#xff0c;\u4f46\u4f60\u4e0d\u9700\u8981\u77e5\u9053\u5185\u90e8\u7535\u8def\u662f\u5982\u4f55\u5de5\u4f5c\u7684\u3002\u9065\u63a7\u5668\u4e0a\u7684\u6309\u94ae\u5c31\u662f\u8bbf\u95ee\u7535\u89c6\u673a\u529f\u80fd\u7684\u201c\u63a5\u53e3\u201d\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<p>\u7ee7\u627f&#xff08;Inheritance&#xff09;&#xff1a;<\/p>\n<ul>\n<li>\u5b9a\u4e49&#xff1a;\u5141\u8bb8\u4e00\u4e2a\u7c7b&#xff08;\u5b50\u7c7b\u6216\u6d3e\u751f\u7c7b&#xff09;\u57fa\u4e8e\u53e6\u4e00\u4e2a\u7c7b&#xff08;\u7236\u7c7b\u6216\u57fa\u7c7b&#xff09;\u6765\u521b\u5efa&#xff0c;\u5b50\u7c7b\u4f1a\u81ea\u52a8\u62e5\u6709\u7236\u7c7b\u7684\u5c5e\u6027\u548c\u65b9\u6cd5&#xff0c;\u5e76\u53ef\u4ee5\u6dfb\u52a0\u65b0\u7684\u5c5e\u6027\u548c\u65b9\u6cd5&#xff0c;\u6216\u4fee\u6539&#xff08;\u91cd\u5199&#xff09;\u7236\u7c7b\u7684\u884c\u4e3a\u3002<\/li>\n<li>\u76ee\u7684&#xff1a;\u5b9e\u73b0\u4ee3\u7801\u91cd\u7528&#xff0c;\u5efa\u7acb\u7c7b\u4e4b\u95f4\u7684\u5c42\u6b21\u5173\u7cfb&#xff0c;\u8868\u8fbe\u201cis-a\u201d\u5173\u7cfb&#xff08;\u4f8b\u5982&#xff0c;Dog is a Animal&#xff09;\u3002<\/li>\n<li>\u7c7b\u6bd4&#xff1a;\u5b69\u5b50\u7ee7\u627f\u4e86\u7236\u6bcd\u7684\u67d0\u4e9b\u7279\u5f81&#xff08;\u5982\u773c\u775b\u989c\u8272\u3001\u8eab\u9ad8\u8d8b\u52bf&#xff09;&#xff0c;\u4f46\u4e5f\u53ef\u80fd\u53d1\u5c55\u51fa\u81ea\u5df1\u72ec\u7279\u7684\u7279\u5f81\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<p>\u591a\u6001&#xff08;Polymorphism&#xff09;&#xff1a;<\/p>\n<ul>\n<li>\u5b9a\u4e49&#xff1a;\u540c\u4e00\u4e2a\u64cd\u4f5c\u4f5c\u7528\u4e8e\u4e0d\u540c\u7684\u5bf9\u8c61&#xff0c;\u53ef\u4ee5\u4ea7\u751f\u4e0d\u540c\u7684\u6267\u884c\u7ed3\u679c\u3002\u591a\u6001\u5141\u8bb8\u4f7f\u7528\u7236\u7c7b\u7c7b\u578b\u7684\u5f15\u7528\u6765\u8c03\u7528\u5b50\u7c7b\u5bf9\u8c61\u7684\u65b9\u6cd5&#xff0c;\u5177\u4f53\u8c03\u7528\u54ea\u4e2a\u65b9\u6cd5\u5728\u8fd0\u884c\u65f6\u51b3\u5b9a&#xff08;\u52a8\u6001\u7ed1\u5b9a&#xff09;\u3002<\/li>\n<li>\u76ee\u7684&#xff1a;\u63d0\u9ad8\u4ee3\u7801\u7684\u7075\u6d3b\u6027\u548c\u53ef\u6269\u5c55\u6027&#xff0c;\u4f7f\u5f97\u7a0b\u5e8f\u53ef\u4ee5\u7f16\u5199\u5f97\u66f4\u52a0\u901a\u7528&#xff0c;\u80fd\u591f\u5904\u7406\u591a\u79cd\u7c7b\u578b\u7684\u5bf9\u8c61\u3002<\/li>\n<li>\u7c7b\u6bd4&#xff1a;\u540c\u6837\u662f\u201c\u53d1\u51fa\u58f0\u97f3\u201d\u8fd9\u4e2a\u64cd\u4f5c&#xff0c;\u72d7\u4f1a\u201c\u6c6a\u6c6a\u201d\u53eb&#xff0c;\u732b\u4f1a\u201c\u55b5\u55b5\u201d\u53eb\u3002\u4f60\u53ea\u9700\u8981\u8bf4\u201c\u53eb\u4e00\u58f0\u201d&#xff0c;\u4e0d\u540c\u7684\u52a8\u7269\u4f1a\u4ee5\u81ea\u5df1\u7684\u65b9\u5f0f\u54cd\u5e94\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<p>\u62bd\u8c61&#xff08;Abstraction&#xff09;&#xff1a;<\/p>\n<ul>\n<li>\u5b9a\u4e49&#xff1a;\u63d0\u53d6\u4e8b\u7269\u7684\u5173\u952e\u7279\u5f81\u548c\u884c\u4e3a&#xff0c;\u5ffd\u7565\u4e0d\u5fc5\u8981\u7684\u7ec6\u8282&#xff0c;\u4ece\u800c\u7b80\u5316\u590d\u6742\u7cfb\u7edf\u3002\u5728Java\u4e2d&#xff0c;\u62bd\u8c61\u901a\u5e38\u901a\u8fc7\u62bd\u8c61\u7c7b&#xff08;abstract class&#xff09;\u548c\u63a5\u53e3&#xff08;interface&#xff09;\u6765\u5b9e\u73b0\u3002<\/li>\n<li>\u76ee\u7684&#xff1a;\u5173\u6ce8\u201c\u505a\u4ec0\u4e48\u201d\u800c\u4e0d\u662f\u201c\u600e\u4e48\u505a\u201d&#xff0c;\u964d\u4f4e\u7cfb\u7edf\u590d\u6742\u5ea6&#xff0c;\u4fbf\u4e8e\u8bbe\u8ba1\u548c\u7406\u89e3\u3002<\/li>\n<li>\u7c7b\u6bd4&#xff1a;\u9a7e\u9a76\u6c7d\u8f66\u65f6&#xff0c;\u4f60\u53ea\u9700\u8981\u77e5\u9053\u65b9\u5411\u76d8\u3001\u6cb9\u95e8\u3001\u5239\u8f66\u7684\u4f5c\u7528&#xff0c;\u800c\u4e0d\u9700\u8981\u4e86\u89e3\u53d1\u52a8\u673a\u5185\u90e8\u7684\u71c3\u70e7\u8fc7\u7a0b\u3002<\/li>\n<\/ul>\n<\/li>\n<p>\u7406\u89e3\u8fd9\u56db\u5927\u652f\u67f1\u662f\u638c\u63e1\u9762\u5411\u5bf9\u8c61\u7f16\u7a0b\u7684\u5173\u952e\u3002\u5728\u540e\u7eed\u7684\u7ae0\u8282\u4e2d&#xff0c;\u6211\u4eec\u5c06\u91cd\u70b9\u63a2\u8ba8\u5c01\u88c5\u548c\u62bd\u8c61&#xff0c;\u56e0\u4e3a\u5b83\u4eec\u76f4\u63a5\u4e0e\u201c\u7c7b\u201d\u548c\u201c\u5bf9\u8c61\u201d\u7684\u5b9a\u4e49\u548c\u521b\u5efa\u7d27\u5bc6\u76f8\u5173\u3002\u7ee7\u627f\u548c\u591a\u6001\u5c06\u5728\u540e\u7eed\u7ae0\u8282\u4e2d\u8be6\u7ec6\u8ba8\u8bba\u3002<\/p>\n<hr \/>\n<h3>\u7b2c\u4e8c\u7ae0&#xff1a;\u7c7b&#xff08;Class&#xff09;\u2014\u2014 \u5bf9\u8c61\u7684\u84dd\u56fe<\/h3>\n<p>\u5982\u679c\u8bf4\u5bf9\u8c61\u662f\u73b0\u5b9e\u4e16\u754c\u4e2d\u7684\u5177\u4f53\u4e8b\u7269&#xff0c;\u90a3\u4e48\u7c7b&#xff08;Class&#xff09; \u5c31\u662f\u521b\u9020\u8fd9\u4e9b\u4e8b\u7269\u7684\u84dd\u56fe\u6216\u6a21\u677f\u3002\u7c7b\u5b9a\u4e49\u4e86\u5bf9\u8c61\u5e94\u8be5\u5177\u6709\u54ea\u4e9b\u7279\u5f81&#xff08;\u5c5e\u6027&#xff09;\u548c\u80fd\u6267\u884c\u54ea\u4e9b\u64cd\u4f5c&#xff08;\u65b9\u6cd5&#xff09;\u3002\u5b83\u672c\u8eab\u4e0d\u662f\u5177\u4f53\u7684\u5b9e\u4f53&#xff0c;\u800c\u662f\u4e00\u79cd\u62bd\u8c61\u7684\u63cf\u8ff0\u3002<\/p>\n<h4>2.1 \u4ec0\u4e48\u662f\u7c7b&#xff1f;<\/h4>\n<p>\u5728Java\u4e2d&#xff0c;\u7c7b\u662f\u4e00\u4e2a\u7528\u6237\u81ea\u5b9a\u4e49\u7684\u6570\u636e\u7c7b\u578b\u3002\u5b83\u5c06\u76f8\u5173\u7684\u6570\u636e\u548c\u64cd\u4f5c\u8fd9\u4e9b\u6570\u636e\u7684\u4ee3\u7801\u7ec4\u7ec7\u5728\u4e00\u8d77\u3002\u4f60\u53ef\u4ee5\u628a\u7c7b\u60f3\u8c61\u6210\u4e00\u4e2a\u6a21\u5177&#xff0c;\u800c\u5bf9\u8c61\u5c31\u662f\u7528\u8fd9\u4e2a\u6a21\u5177\u751f\u4ea7\u51fa\u6765\u7684\u5177\u4f53\u4ea7\u54c1\u3002<\/p>\n<p>\u7c7b\u7684\u4e3b\u8981\u7ec4\u6210\u90e8\u5206&#xff1a;<\/p>\n<li>\u5b57\u6bb5&#xff08;Fields&#xff09;&#xff1a;\u4e5f\u79f0\u4e3a\u5c5e\u6027&#xff08;Properties&#xff09; \u6216\u6210\u5458\u53d8\u91cf&#xff08;Member Variables&#xff09;\u3002\u5b83\u4eec\u4ee3\u8868\u4e86\u7c7b\u7684\u72b6\u6001\u6216\u7279\u5f81\u3002\u4f8b\u5982&#xff0c;\u4e00\u4e2aPerson\u7c7b\u53ef\u80fd\u6709name&#xff08;\u59d3\u540d&#xff09;\u3001age&#xff08;\u5e74\u9f84&#xff09;\u3001height&#xff08;\u8eab\u9ad8&#xff09;\u7b49\u5b57\u6bb5\u3002<\/li>\n<li>\u65b9\u6cd5&#xff08;Methods&#xff09;&#xff1a;\u4e5f\u79f0\u4e3a\u6210\u5458\u51fd\u6570&#xff08;Member Functions&#xff09;\u3002\u5b83\u4eec\u5b9a\u4e49\u4e86\u7c7b\u7684\u884c\u4e3a\u6216\u80fd\u6267\u884c\u7684\u64cd\u4f5c\u3002\u4f8b\u5982&#xff0c;\u4e00\u4e2aPerson\u7c7b\u53ef\u80fd\u6709walk()&#xff08;\u884c\u8d70&#xff09;\u3001talk()&#xff08;\u8bf4\u8bdd&#xff09;\u3001eat()&#xff08;\u5403\u996d&#xff09;\u7b49\u65b9\u6cd5\u3002<\/li>\n<li>\u6784\u9020\u5668&#xff08;Constructors&#xff09;&#xff1a;\u4e00\u79cd\u7279\u6b8a\u7684\u65b9\u6cd5&#xff0c;\u7528\u4e8e\u5728\u521b\u5efa\u5bf9\u8c61\u65f6\u521d\u59cb\u5316\u5bf9\u8c61\u7684\u72b6\u6001\u3002\u5b83\u7684\u540d\u5b57\u5fc5\u987b\u4e0e\u7c7b\u540d\u5b8c\u5168\u76f8\u540c&#xff0c;\u4e14\u6ca1\u6709\u8fd4\u56de\u7c7b\u578b&#xff08;\u8fdevoid\u90fd\u4e0d\u80fd\u6709&#xff09;\u3002<\/li>\n<li>\u4ee3\u7801\u5757&#xff08;Code Blocks&#xff09;&#xff1a;\u5305\u62ec\u5b9e\u4f8b\u521d\u59cb\u5316\u5757\u548c\u9759\u6001\u521d\u59cb\u5316\u5757&#xff0c;\u7528\u4e8e\u5728\u5bf9\u8c61\u521b\u5efa\u6216\u7c7b\u52a0\u8f7d\u65f6\u6267\u884c\u4e00\u4e9b\u521d\u59cb\u5316\u4ee3\u7801\u3002<\/li>\n<li>\u5185\u90e8\u7c7b&#xff08;Inner Classes&#xff09;&#xff1a;\u5b9a\u4e49\u5728\u53e6\u4e00\u4e2a\u7c7b\u5185\u90e8\u7684\u7c7b\u3002<\/li>\n<h4>2.2 \u5b9a\u4e49\u7c7b&#xff1a;\u8bed\u6cd5\u4e0e\u793a\u4f8b<\/h4>\n<p>\u5728Java\u4e2d&#xff0c;\u4f7f\u7528class\u5173\u952e\u5b57\u6765\u5b9a\u4e49\u4e00\u4e2a\u7c7b\u3002\u57fa\u672c\u8bed\u6cd5\u5982\u4e0b&#xff1a;<\/p>\n<p><span class=\"token punctuation\">[<\/span>\u8bbf\u95ee\u4fee\u9970\u7b26<span class=\"token punctuation\">]<\/span> <span class=\"token keyword\">class<\/span> \u7c7b\u540d <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token comment\">\/\/ \u5b57\u6bb5&#xff08;\u6210\u5458\u53d8\u91cf&#xff09;<\/span><br \/>\n    <span class=\"token punctuation\">[<\/span>\u8bbf\u95ee\u4fee\u9970\u7b26<span class=\"token punctuation\">]<\/span> \u6570\u636e\u7c7b\u578b \u5b57\u6bb5\u540d <span class=\"token punctuation\">[<\/span><span class=\"token operator\">&#061;<\/span> \u521d\u59cb\u503c<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ \u6784\u9020\u5668<\/span><br \/>\n    <span class=\"token punctuation\">[<\/span>\u8bbf\u95ee\u4fee\u9970\u7b26<span class=\"token punctuation\">]<\/span> \u7c7b\u540d<span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">[<\/span>\u53c2\u6570\u5217\u8868<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token comment\">\/\/ \u6784\u9020\u5668\u4ee3\u7801&#xff0c;\u7528\u4e8e\u521d\u59cb\u5316\u5bf9\u8c61<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ \u65b9\u6cd5&#xff08;\u6210\u5458\u51fd\u6570&#xff09;<\/span><br \/>\n    <span class=\"token punctuation\">[<\/span>\u8bbf\u95ee\u4fee\u9970\u7b26<span class=\"token punctuation\">]<\/span> <span class=\"token punctuation\">[<\/span>\u8fd4\u56de\u7c7b\u578b<span class=\"token punctuation\">]<\/span> \u65b9\u6cd5\u540d<span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">[<\/span>\u53c2\u6570\u5217\u8868<span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token comment\">\/\/ \u65b9\u6cd5\u4f53&#xff0c;\u5305\u542b\u6267\u884c\u7684\u4ee3\u7801<\/span><br \/>\n        <span class=\"token punctuation\">[<\/span><span class=\"token keyword\">return<\/span> \u8fd4\u56de\u503c<span class=\"token punctuation\">;<\/span><span class=\"token punctuation\">]<\/span> <span class=\"token comment\">\/\/ \u5982\u679c\u8fd4\u56de\u7c7b\u578b\u4e0d\u662fvoid<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u8bbf\u95ee\u4fee\u9970\u7b26&#xff08;Access Modifiers&#xff09; \u63a7\u5236\u7c7b\u3001\u5b57\u6bb5\u3001\u65b9\u6cd5\u7b49\u7684\u8bbf\u95ee\u6743\u9650\u3002\u5e38\u89c1\u7684\u6709&#xff1a;<\/p>\n<ul>\n<li>public&#xff1a;\u5bf9\u6240\u6709\u7c7b\u53ef\u89c1\u3002<\/li>\n<li>private&#xff1a;\u4ec5\u5728\u672c\u7c7b\u5185\u90e8\u53ef\u89c1\u3002<\/li>\n<li>protected&#xff1a;\u5728\u672c\u7c7b\u3001\u540c\u4e00\u5305\u5185\u7684\u7c7b\u4ee5\u53ca\u5b50\u7c7b\u4e2d\u53ef\u89c1\u3002<\/li>\n<li>&#xff08;\u9ed8\u8ba4&#xff0c;\u4e0d\u5199&#xff09;&#xff1a;\u4ec5\u5728\u672c\u5305\u5185\u53ef\u89c1&#xff08;\u5305\u8bbf\u95ee\u6743\u9650&#xff09;\u3002<\/li>\n<\/ul>\n<p>\u8ba9\u6211\u4eec\u901a\u8fc7\u4e00\u4e2a\u5177\u4f53\u7684\u4f8b\u5b50\u6765\u7406\u89e3&#xff1a;<\/p>\n<p>\u793a\u4f8b&#xff1a;\u5b9a\u4e49\u4e00\u4e2a Person \u7c7b<\/p>\n<p><span class=\"token comment\">\/\/ Person.java<\/span><br \/>\n<span class=\"token keyword\">public<\/span> <span class=\"token keyword\">class<\/span> <span class=\"token class-name\">Person<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token comment\">\/\/ &#8212;- \u5b57\u6bb5&#xff08;\u6210\u5458\u53d8\u91cf&#xff09; &#8212;-<\/span><br \/>\n    <span class=\"token comment\">\/\/ \u4f7f\u7528 private \u4fee\u9970&#xff0c;\u5c01\u88c5\u6570\u636e&#xff0c;\u5916\u90e8\u4e0d\u80fd\u76f4\u63a5\u8bbf\u95ee<\/span><br \/>\n    <span class=\"token keyword\">private<\/span> <span class=\"token class-name\">String<\/span> name<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">private<\/span> <span class=\"token keyword\">int<\/span> age<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">private<\/span> <span class=\"token keyword\">double<\/span> height<span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u8eab\u9ad8&#xff08;\u7c73&#xff09;<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ &#8212;- \u6784\u9020\u5668&#xff08;Constructors&#xff09; &#8212;-<\/span><br \/>\n    <span class=\"token comment\">\/\/ \u65e0\u53c2\u6784\u9020\u5668&#xff1a;\u521b\u5efa\u5bf9\u8c61\u65f6\u5982\u679c\u4e0d\u63d0\u4f9b\u53c2\u6570&#xff0c;\u5219\u8c03\u7528\u6b64\u6784\u9020\u5668<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token comment\">\/\/ \u53ef\u4ee5\u8bbe\u7f6e\u9ed8\u8ba4\u503c<\/span><br \/>\n        <span class=\"token keyword\">this<\/span><span class=\"token punctuation\">.<\/span>name <span class=\"token operator\">&#061;<\/span> <span class=\"token string\">&#034;\u672a\u77e5&#034;<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">this<\/span><span class=\"token punctuation\">.<\/span>age <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">this<\/span><span class=\"token punctuation\">.<\/span>height <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0.0<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\u521b\u5efa\u4e86\u4e00\u4e2a Person \u5bf9\u8c61&#xff08;\u65e0\u53c2\u6784\u9020\u5668&#xff09;&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ \u6709\u53c2\u6784\u9020\u5668&#xff1a;\u521b\u5efa\u5bf9\u8c61\u65f6\u63d0\u4f9b\u5fc5\u8981\u7684\u521d\u59cb\u503c<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token class-name\">String<\/span> name<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">int<\/span> age<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">double<\/span> height<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token comment\">\/\/ \u4f7f\u7528 this \u5173\u952e\u5b57\u533a\u5206\u540c\u540d\u7684\u53c2\u6570\u548c\u5b57\u6bb5<\/span><br \/>\n        <span class=\"token keyword\">this<\/span><span class=\"token punctuation\">.<\/span>name <span class=\"token operator\">&#061;<\/span> name<span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">this<\/span><span class=\"token punctuation\">.<\/span>age <span class=\"token operator\">&#061;<\/span> age<span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">this<\/span><span class=\"token punctuation\">.<\/span>height <span class=\"token operator\">&#061;<\/span> height<span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\u521b\u5efa\u4e86\u4e00\u4e2a Person \u5bf9\u8c61&#xff08;\u6709\u53c2\u6784\u9020\u5668&#xff09;: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> <span class=\"token keyword\">this<\/span><span class=\"token punctuation\">.<\/span>name<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ &#8212;- \u65b9\u6cd5&#xff08;\u6210\u5458\u51fd\u6570&#xff09; &#8212;-<\/span><br \/>\n    <span class=\"token comment\">\/\/ getter \u65b9\u6cd5&#xff1a;\u7528\u4e8e\u83b7\u53d6\u79c1\u6709\u5b57\u6bb5\u7684\u503c<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token class-name\">String<\/span> <span class=\"token function\">getName<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> name<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ setter \u65b9\u6cd5&#xff1a;\u7528\u4e8e\u8bbe\u7f6e\u79c1\u6709\u5b57\u6bb5\u7684\u503c&#xff08;\u53ef\u4ee5\u5305\u542b\u9a8c\u8bc1\u903b\u8f91&#xff09;<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">setName<\/span><span class=\"token punctuation\">(<\/span><span class=\"token class-name\">String<\/span> name<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>name <span class=\"token operator\">!&#061;<\/span> <span class=\"token keyword\">null<\/span> <span class=\"token operator\">&amp;&amp;<\/span> <span class=\"token operator\">!<\/span>name<span class=\"token punctuation\">.<\/span><span class=\"token function\">trim<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">.<\/span><span class=\"token function\">isEmpty<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token keyword\">this<\/span><span class=\"token punctuation\">.<\/span>name <span class=\"token operator\">&#061;<\/span> name<span class=\"token punctuation\">.<\/span><span class=\"token function\">trim<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u53bb\u9664\u9996\u5c3e\u7a7a\u683c<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span> <span class=\"token keyword\">else<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\u59d3\u540d\u4e0d\u80fd\u4e3a\u7a7a&#xff01;&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">int<\/span> <span class=\"token function\">getAge<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> age<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">setAge<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">int<\/span> age<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>age <span class=\"token operator\">&gt;&#061;<\/span> <span class=\"token number\">0<\/span> <span class=\"token operator\">&amp;&amp;<\/span> age <span class=\"token operator\">&lt;&#061;<\/span> <span class=\"token number\">150<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token keyword\">this<\/span><span class=\"token punctuation\">.<\/span>age <span class=\"token operator\">&#061;<\/span> age<span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span> <span class=\"token keyword\">else<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\u5e74\u9f84\u5fc5\u987b\u57280\u5230150\u4e4b\u95f4&#xff01;&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">double<\/span> <span class=\"token function\">getHeight<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> height<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">setHeight<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">double<\/span> height<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>height <span class=\"token operator\">&gt;<\/span> <span class=\"token number\">0<\/span> <span class=\"token operator\">&amp;&amp;<\/span> height <span class=\"token operator\">&lt;<\/span> <span class=\"token number\">3.0<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token keyword\">this<\/span><span class=\"token punctuation\">.<\/span>height <span class=\"token operator\">&#061;<\/span> height<span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span> <span class=\"token keyword\">else<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\u8eab\u9ad8\u5fc5\u987b\u5927\u4e8e0\u4e14\u5c0f\u4e8e3\u7c73&#xff01;&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ \u884c\u4e3a\u65b9\u6cd5<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">walk<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span>name <span class=\"token operator\">&#043;<\/span> <span class=\"token string\">&#034; \u6b63\u5728\u8d70\u8def\u3002&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">talk<\/span><span class=\"token punctuation\">(<\/span><span class=\"token class-name\">String<\/span> message<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span>name <span class=\"token operator\">&#043;<\/span> <span class=\"token string\">&#034; \u8bf4: \\\\&#034;&#034;<\/span> <span class=\"token operator\">&#043;<\/span> message <span class=\"token operator\">&#043;<\/span> <span class=\"token string\">&#034;\\\\&#034;&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">eat<\/span><span class=\"token punctuation\">(<\/span><span class=\"token class-name\">String<\/span> food<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span>name <span class=\"token operator\">&#043;<\/span> <span class=\"token string\">&#034; \u6b63\u5728\u5403 &#034;<\/span> <span class=\"token operator\">&#043;<\/span> food <span class=\"token operator\">&#043;<\/span> <span class=\"token string\">&#034;\u3002&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ \u7279\u6b8a\u65b9\u6cd5&#xff1a;toString() &#8211; \u8fd4\u56de\u5bf9\u8c61\u7684\u5b57\u7b26\u4e32\u8868\u793a&#xff0c;\u4fbf\u4e8e\u6253\u5370<\/span><br \/>\n    <span class=\"token annotation punctuation\">&#064;Override<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token class-name\">String<\/span> <span class=\"token function\">toString<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> <span class=\"token string\">&#034;Person{&#034;<\/span> <span class=\"token operator\">&#043;<\/span><br \/>\n                <span class=\"token string\">&#034;name&#061;&#039;&#034;<\/span> <span class=\"token operator\">&#043;<\/span> name <span class=\"token operator\">&#043;<\/span> <span class=\"token string\">&#039;\\\\&#039;&#039;<\/span> <span class=\"token operator\">&#043;<\/span><br \/>\n                <span class=\"token string\">&#034;, age&#061;&#034;<\/span> <span class=\"token operator\">&#043;<\/span> age <span class=\"token operator\">&#043;<\/span><br \/>\n                <span class=\"token string\">&#034;, height&#061;&#034;<\/span> <span class=\"token operator\">&#043;<\/span> height <span class=\"token operator\">&#043;<\/span><br \/>\n                <span class=\"token string\">&#039;}&#039;<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u4ee3\u7801\u89e3\u6790&#xff1a;<\/p>\n<li>public class Person&#xff1a;\u5b9a\u4e49\u4e86\u4e00\u4e2a\u540d\u4e3aPerson\u7684\u516c\u5171\u7c7b\u3002\u7c7b\u540d\u901a\u5e38\u4f7f\u7528\u5927\u9a7c\u5cf0\u547d\u540d\u6cd5&#xff08;PascalCase&#xff09;\u3002<\/li>\n<li>\u5b57\u6bb5&#xff1a;name, age, height \u90fd\u88ab\u58f0\u660e\u4e3aprivate&#xff0c;\u5b9e\u73b0\u4e86\u5c01\u88c5\u3002\u5916\u90e8\u4ee3\u7801\u4e0d\u80fd\u76f4\u63a5\u8bbf\u95ee\u6216\u4fee\u6539\u5b83\u4eec&#xff0c;\u5fc5\u987b\u901a\u8fc7getter\u548csetter\u65b9\u6cd5\u3002<\/li>\n<li>\u6784\u9020\u5668&#xff1a;\n<ul>\n<li>Person() \u662f\u65e0\u53c2\u6784\u9020\u5668\u3002\u5373\u4f7f\u6211\u4eec\u4e0d\u5199&#xff0c;Java\u7f16\u8bd1\u5668\u4e5f\u4f1a\u81ea\u52a8\u63d0\u4f9b\u4e00\u4e2a\u9ed8\u8ba4\u7684\u65e0\u53c2\u6784\u9020\u5668&#xff08;\u5982\u679c\u7c7b\u4e2d\u6ca1\u6709\u5176\u4ed6\u6784\u9020\u5668\u7684\u8bdd&#xff09;\u3002\u4f46\u4e00\u65e6\u6211\u4eec\u5b9a\u4e49\u4e86\u6709\u53c2\u6784\u9020\u5668&#xff0c;\u65e0\u53c2\u6784\u9020\u5668\u5c31\u9700\u8981\u663e\u5f0f\u5b9a\u4e49&#xff0c;\u5426\u5219\u65e0\u6cd5\u4f7f\u7528\u65e0\u53c2\u65b9\u5f0f\u521b\u5efa\u5bf9\u8c61\u3002<\/li>\n<li>Person(String name, int age, double height) \u662f\u6709\u53c2\u6784\u9020\u5668&#xff0c;\u5141\u8bb8\u5728\u521b\u5efa\u5bf9\u8c61\u65f6\u521d\u59cb\u5316\u5176\u72b6\u6001\u3002<\/li>\n<li>this \u5173\u952e\u5b57\u5728\u8fd9\u91cc\u7528\u6765\u5f15\u7528\u5f53\u524d\u5bf9\u8c61\u7684\u5b9e\u4f8b&#xff0c;this.name &#061; name \u8868\u793a\u5c06\u53c2\u6570name\u7684\u503c\u8d4b\u7ed9\u5f53\u524d\u5bf9\u8c61\u7684name\u5b57\u6bb5\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\u65b9\u6cd5&#xff1a;\n<ul>\n<li>getter\u548csetter\u65b9\u6cd5&#xff1a;\u8fd9\u662f\u5c01\u88c5\u7684\u5178\u578b\u5e94\u7528\u3002getName()\u8fd4\u56dename\u5b57\u6bb5\u7684\u503c&#xff0c;setName(String name)\u7528\u4e8e\u8bbe\u7f6ename\u5b57\u6bb5\u7684\u503c\u3002\u5728setter\u4e2d\u52a0\u5165\u4e86\u7b80\u5355\u7684\u9a8c\u8bc1\u903b\u8f91&#xff08;\u68c0\u67e5\u59d3\u540d\u662f\u5426\u4e3a\u7a7a&#xff09;&#xff0c;\u8fd9\u4f53\u73b0\u4e86\u65b9\u6cd5\u53ef\u4ee5\u5305\u542b\u4e1a\u52a1\u903b\u8f91\u3002<\/li>\n<li>\u884c\u4e3a\u65b9\u6cd5&#xff1a;walk(), talk(String message), eat(String food) \u5b9a\u4e49\u4e86Person\u5bf9\u8c61\u53ef\u4ee5\u6267\u884c\u7684\u64cd\u4f5c\u3002<\/li>\n<li>toString() \u65b9\u6cd5&#xff1a;\u8fd9\u662f\u4e00\u4e2a\u4eceObject\u7c7b&#xff08;\u6240\u6709\u7c7b\u7684\u7236\u7c7b&#xff09;\u7ee7\u627f\u7684\u65b9\u6cd5&#xff0c;\u6211\u4eec\u901a\u8fc7&#064;Override\u6ce8\u89e3\u8868\u660e\u6211\u4eec\u6b63\u5728\u91cd\u5199\u5b83\u3002\u91cd\u5199toString()\u65b9\u6cd5\u53ef\u4ee5\u81ea\u5b9a\u4e49\u5bf9\u8c61\u7684\u5b57\u7b26\u4e32\u8868\u793a&#xff0c;\u5f53\u6253\u5370\u5bf9\u8c61\u65f6\u4f1a\u81ea\u52a8\u8c03\u7528\u3002\u4f8b\u5982&#xff0c;System.out.println(person) \u4f1a\u8f93\u51fa\u7c7b\u4f3c Person{name&#061;&#039;Alice&#039;, age&#061;25, height&#061;1.68} \u7684\u5b57\u7b26\u4e32\u3002<\/li>\n<\/ul>\n<\/li>\n<h4>2.3 \u6784\u9020\u5668\u8be6\u89e3<\/h4>\n<p>\u6784\u9020\u5668\u662f\u7c7b\u4e2d\u975e\u5e38\u91cd\u8981\u7684\u7ec4\u6210\u90e8\u5206&#xff0c;\u5b83\u51b3\u5b9a\u4e86\u5bf9\u8c61\u521b\u5efa\u65f6\u7684\u521d\u59cb\u5316\u8fc7\u7a0b\u3002<\/p>\n<p>\u6784\u9020\u5668\u7684\u7279\u70b9&#xff1a;<\/p>\n<ul>\n<li>\u540d\u79f0\u5fc5\u987b\u4e0e\u7c7b\u540d\u5b8c\u5168\u76f8\u540c&#xff08;\u5305\u62ec\u5927\u5c0f\u5199&#xff09;\u3002<\/li>\n<li>\u6ca1\u6709\u8fd4\u56de\u7c7b\u578b&#xff08;\u65e2\u4e0d\u80fd\u5199void&#xff0c;\u4e5f\u4e0d\u80fd\u5199\u5176\u4ed6\u7c7b\u578b&#xff09;\u3002<\/li>\n<li>\u5728\u521b\u5efa\u5bf9\u8c61\u65f6&#xff08;\u4f7f\u7528new\u5173\u952e\u5b57&#xff09;\u7531Java\u865a\u62df\u673a&#xff08;JVM&#xff09;\u81ea\u52a8\u8c03\u7528\u3002<\/li>\n<li>\u4e00\u4e2a\u7c7b\u53ef\u4ee5\u6709\u591a\u4e2a\u6784\u9020\u5668&#xff0c;\u53ea\u8981\u5b83\u4eec\u7684\u53c2\u6570\u5217\u8868\u4e0d\u540c&#xff08;\u53c2\u6570\u7684\u7c7b\u578b\u3001\u6570\u91cf\u6216\u987a\u5e8f\u4e0d\u540c&#xff09;&#xff0c;\u8fd9\u79f0\u4e3a\u6784\u9020\u5668\u91cd\u8f7d&#xff08;Constructor Overloading&#xff09;\u3002<\/li>\n<\/ul>\n<p>\u793a\u4f8b&#xff1a;\u6784\u9020\u5668\u91cd\u8f7d<\/p>\n<p><span class=\"token comment\">\/\/ \u5728 Person \u7c7b\u4e2d\u6dfb\u52a0\u66f4\u591a\u6784\u9020\u5668<\/span><br \/>\n<span class=\"token keyword\">public<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token class-name\">String<\/span> name<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">this<\/span><span class=\"token punctuation\">(<\/span>name<span class=\"token punctuation\">,<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">0.0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u8c03\u7528\u5df2\u6709\u7684\u6709\u53c2\u6784\u9020\u5668&#xff0c;\u907f\u514d\u4ee3\u7801\u91cd\u590d<\/span><br \/>\n    <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\u521b\u5efa\u4e86\u4e00\u4e2a Person \u5bf9\u8c61&#xff08;\u4ec5\u59d3\u540d\u6784\u9020\u5668&#xff09;: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> <span class=\"token keyword\">this<\/span><span class=\"token punctuation\">.<\/span>name<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p><span class=\"token keyword\">public<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token class-name\">String<\/span> name<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">int<\/span> age<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">this<\/span><span class=\"token punctuation\">(<\/span>name<span class=\"token punctuation\">,<\/span> age<span class=\"token punctuation\">,<\/span> <span class=\"token number\">0.0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u8c03\u7528\u5df2\u6709\u7684\u6709\u53c2\u6784\u9020\u5668<\/span><br \/>\n    <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\u521b\u5efa\u4e86\u4e00\u4e2a Person \u5bf9\u8c61&#xff08;\u59d3\u540d\u548c\u5e74\u9f84\u6784\u9020\u5668&#xff09;: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> <span class=\"token keyword\">this<\/span><span class=\"token punctuation\">.<\/span>name<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u73b0\u5728&#xff0c;\u521b\u5efaPerson\u5bf9\u8c61\u65f6&#xff0c;\u53ef\u4ee5\u6839\u636e\u9700\u8981\u9009\u62e9\u4e0d\u540c\u7684\u6784\u9020\u5668&#xff1a;<\/p>\n<p><span class=\"token class-name\">Person<\/span> person1 <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u8c03\u7528\u65e0\u53c2\u6784\u9020\u5668<\/span><br \/>\n<span class=\"token class-name\">Person<\/span> person2 <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Bob&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u8c03\u7528\u4ec5\u59d3\u540d\u6784\u9020\u5668<\/span><br \/>\n<span class=\"token class-name\">Person<\/span> person3 <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Charlie&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">30<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u8c03\u7528\u59d3\u540d\u548c\u5e74\u9f84\u6784\u9020\u5668<\/span><br \/>\n<span class=\"token class-name\">Person<\/span> person4 <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Diana&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">28<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1.75<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u8c03\u7528\u5168\u53c2\u6784\u9020\u5668<\/span><\/p>\n<p>this() \u8c03\u7528&#xff1a;\u5728\u6784\u9020\u5668\u5185\u90e8&#xff0c;\u53ef\u4ee5\u4f7f\u7528this(\u53c2\u6570\u5217\u8868)\u6765\u8c03\u7528\u540c\u4e00\u4e2a\u7c7b\u4e2d\u7684\u53e6\u4e00\u4e2a\u6784\u9020\u5668\u3002\u8fd9\u5fc5\u987b\u662f\u6784\u9020\u5668\u4e2d\u7684\u7b2c\u4e00\u6761\u8bed\u53e5\u3002\u8fd9\u6709\u52a9\u4e8e\u51cf\u5c11\u4ee3\u7801\u91cd\u590d\u3002<\/p>\n<h4>2.4 \u9759\u6001\u6210\u5458&#xff08;Static Members&#xff09;<\/h4>\n<p>\u9664\u4e86\u5b9e\u4f8b\u6210\u5458&#xff08;\u5b57\u6bb5\u548c\u65b9\u6cd5&#xff09;&#xff0c;\u7c7b\u8fd8\u53ef\u4ee5\u62e5\u6709\u9759\u6001\u6210\u5458\u3002\u9759\u6001\u6210\u5458\u5c5e\u4e8e\u7c7b\u672c\u8eab&#xff0c;\u800c\u4e0d\u662f\u7c7b\u7684\u67d0\u4e2a\u7279\u5b9a\u5b9e\u4f8b\u3002<\/p>\n<ul>\n<li>\u9759\u6001\u5b57\u6bb5&#xff08;Static Fields&#xff09;&#xff1a;\u4e5f\u79f0\u4e3a\u7c7b\u53d8\u91cf\u3002\u65e0\u8bba\u521b\u5efa\u591a\u5c11\u4e2a\u5bf9\u8c61&#xff0c;\u9759\u6001\u5b57\u6bb5\u5728\u5185\u5b58\u4e2d\u53ea\u6709\u4e00\u4efd\u62f7\u8d1d&#xff0c;\u88ab\u6240\u6709\u5b9e\u4f8b\u5171\u4eab\u3002<\/li>\n<li>\u9759\u6001\u65b9\u6cd5&#xff08;Static Methods&#xff09;&#xff1a;\u4e5f\u79f0\u4e3a\u7c7b\u65b9\u6cd5\u3002\u5b83\u4eec\u4e0d\u4f9d\u8d56\u4e8e\u4efb\u4f55\u5bf9\u8c61\u5b9e\u4f8b&#xff0c;\u53ef\u4ee5\u76f4\u63a5\u901a\u8fc7\u7c7b\u540d\u8c03\u7528\u3002\u9759\u6001\u65b9\u6cd5\u5185\u90e8\u4e0d\u80fd\u76f4\u63a5\u8bbf\u95ee\u975e\u9759\u6001&#xff08;\u5b9e\u4f8b&#xff09;\u6210\u5458&#xff0c;\u56e0\u4e3a\u5b83\u4eec\u6ca1\u6709this\u5f15\u7528\u3002<\/li>\n<\/ul>\n<p>\u793a\u4f8b&#xff1a;\u5728 Person \u7c7b\u4e2d\u6dfb\u52a0\u9759\u6001\u6210\u5458<\/p>\n<p><span class=\"token keyword\">public<\/span> <span class=\"token keyword\">class<\/span> <span class=\"token class-name\">Person<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token comment\">\/\/ &#8230; (\u4e4b\u524d\u7684\u5b57\u6bb5\u548c\u65b9\u6cd5)<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ \u9759\u6001\u5b57\u6bb5&#xff1a;\u7edf\u8ba1\u521b\u5efa\u7684 Person \u5bf9\u8c61\u603b\u6570<\/span><br \/>\n    <span class=\"token keyword\">private<\/span> <span class=\"token keyword\">static<\/span> <span class=\"token keyword\">int<\/span> totalPersonCount <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ \u5728\u6784\u9020\u5668\u4e2d\u589e\u52a0\u8ba1\u6570<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token comment\">\/\/ &#8230; (\u4e4b\u524d\u7684\u521d\u59cb\u5316\u4ee3\u7801)<\/span><br \/>\n        totalPersonCount<span class=\"token operator\">&#043;&#043;<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u6bcf\u521b\u5efa\u4e00\u4e2a\u5bf9\u8c61&#xff0c;\u8ba1\u6570\u52a01<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token keyword\">public<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token class-name\">String<\/span> name<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">int<\/span> age<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">double<\/span> height<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token comment\">\/\/ &#8230; (\u4e4b\u524d\u7684\u521d\u59cb\u5316\u4ee3\u7801)<\/span><br \/>\n        totalPersonCount<span class=\"token operator\">&#043;&#043;<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u6bcf\u521b\u5efa\u4e00\u4e2a\u5bf9\u8c61&#xff0c;\u8ba1\u6570\u52a01<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ \u9759\u6001\u65b9\u6cd5&#xff1a;\u83b7\u53d6\u603b\u4eba\u6570<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">static<\/span> <span class=\"token keyword\">int<\/span> <span class=\"token function\">getTotalPersonCount<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">return<\/span> totalPersonCount<span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ \u9759\u6001\u65b9\u6cd5&#xff1a;\u6bd4\u8f83\u4e24\u4e2a\u8eab\u9ad8&#xff08;\u4e0d\u4f9d\u8d56\u4e8e\u5177\u4f53\u5bf9\u8c61&#xff09;<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">static<\/span> <span class=\"token class-name\">String<\/span> <span class=\"token function\">compareHeight<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">double<\/span> height1<span class=\"token punctuation\">,<\/span> <span class=\"token keyword\">double<\/span> height2<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>height1 <span class=\"token operator\">&gt;<\/span> height2<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token keyword\">return<\/span> <span class=\"token string\">&#034;\u7b2c\u4e00\u4e2a\u4eba\u66f4\u9ad8&#034;<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span> <span class=\"token keyword\">else<\/span> <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>height1 <span class=\"token operator\">&lt;<\/span> height2<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token keyword\">return<\/span> <span class=\"token string\">&#034;\u7b2c\u4e8c\u4e2a\u4eba\u66f4\u9ad8&#034;<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span> <span class=\"token keyword\">else<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n            <span class=\"token keyword\">return<\/span> <span class=\"token string\">&#034;\u4e24\u4eba\u4e00\u6837\u9ad8&#034;<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ \u6ce8\u610f&#xff1a;\u9759\u6001\u65b9\u6cd5\u4e0d\u80fd\u76f4\u63a5\u8bbf\u95ee\u5b9e\u4f8b\u5b57\u6bb5<\/span><br \/>\n    <span class=\"token comment\">\/\/ public static void printName() {<\/span><br \/>\n    <span class=\"token comment\">\/\/     System.out.println(name); \/\/ \u7f16\u8bd1\u9519\u8bef&#xff01;name \u662f\u5b9e\u4f8b\u5b57\u6bb5<\/span><br \/>\n    <span class=\"token comment\">\/\/ }<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u4f7f\u7528\u9759\u6001\u6210\u5458&#xff1a;<\/p>\n<p><span class=\"token keyword\">public<\/span> <span class=\"token keyword\">class<\/span> <span class=\"token class-name\">StaticDemo<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">static<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">main<\/span><span class=\"token punctuation\">(<\/span><span class=\"token class-name\">String<\/span><span class=\"token punctuation\">[<\/span><span class=\"token punctuation\">]<\/span> args<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\u521d\u59cb\u603b\u4eba\u6570: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">.<\/span><span class=\"token function\">getTotalPersonCount<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ 0<\/span><\/p>\n<p>        <span class=\"token class-name\">Person<\/span> p1 <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Alice&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">25<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1.68<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">Person<\/span> p2 <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Bob&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">30<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1.75<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\u521b\u5efa\u4e24\u4e2a\u5bf9\u8c61\u540e\u603b\u4eba\u6570: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">.<\/span><span class=\"token function\">getTotalPersonCount<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ 2<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ \u8c03\u7528\u9759\u6001\u65b9\u6cd5<\/span><br \/>\n        <span class=\"token class-name\">String<\/span> result <span class=\"token operator\">&#061;<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">.<\/span><span class=\"token function\">compareHeight<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1.80<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1.70<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span>result<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u7b2c\u4e00\u4e2a\u4eba\u66f4\u9ad8<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u5173\u952e\u70b9&#xff1a;<\/p>\n<ul>\n<li>\u9759\u6001\u6210\u5458\u901a\u8fc7\u7c7b\u540d.\u6210\u5458\u540d\u8bbf\u95ee&#xff08;\u5982Person.getTotalPersonCount()&#xff09;\u3002<\/li>\n<li>\u9759\u6001\u6210\u5458\u5728\u7c7b\u52a0\u8f7d\u65f6\u521d\u59cb\u5316&#xff0c;\u65e9\u4e8e\u4efb\u4f55\u5bf9\u8c61\u7684\u521b\u5efa\u3002<\/li>\n<li>\u9759\u6001\u65b9\u6cd5\u5e38\u7528\u4e8e\u5de5\u5177\u65b9\u6cd5&#xff08;\u5982Math.max()&#xff09;\u3001\u5de5\u5382\u65b9\u6cd5\u6216\u8bbf\u95ee\u7c7b\u7ea7\u522b\u7684\u72b6\u6001\u3002<\/li>\n<\/ul>\n<hr \/>\n<h3>\u7b2c\u4e09\u7ae0&#xff1a;\u5bf9\u8c61&#xff08;Object&#xff09;\u2014\u2014 \u7c7b\u7684\u5b9e\u4f8b<\/h3>\n<p>\u5982\u679c\u8bf4\u7c7b\u662f\u84dd\u56fe&#xff0c;\u90a3\u4e48\u5bf9\u8c61&#xff08;Object&#xff09; \u5c31\u662f\u6839\u636e\u8fd9\u4e2a\u84dd\u56fe\u5b9e\u9645\u5efa\u9020\u51fa\u6765\u7684\u5177\u4f53\u5b9e\u4f53\u3002\u5bf9\u8c61\u662f\u7a0b\u5e8f\u8fd0\u884c\u65f6\u7684\u57fa\u672c\u5355\u5143&#xff0c;\u5b83\u62e5\u6709\u7c7b\u6240\u5b9a\u4e49\u7684\u72b6\u6001&#xff08;\u5b57\u6bb5\u7684\u503c&#xff09;\u548c\u884c\u4e3a&#xff08;\u65b9\u6cd5\u7684\u5b9e\u73b0&#xff09;\u3002<\/p>\n<h4>3.1 \u4ec0\u4e48\u662f\u5bf9\u8c61&#xff1f;<\/h4>\n<p>\u5bf9\u8c61\u662f\u7c7b\u7684\u4e00\u4e2a\u5b9e\u4f8b&#xff08;Instance&#xff09;\u3002\u5f53\u4f60\u4f7f\u7528new\u5173\u952e\u5b57\u521b\u5efa\u4e00\u4e2a\u7c7b\u7684\u5b9e\u4f8b\u65f6&#xff0c;\u5c31\u8bde\u751f\u4e86\u4e00\u4e2a\u65b0\u7684\u5bf9\u8c61\u3002\u6bcf\u4e2a\u5bf9\u8c61\u90fd\u6709\u81ea\u5df1\u72ec\u7acb\u7684\u4e00\u5957\u5b9e\u4f8b\u5b57\u6bb5&#xff08;\u975e\u9759\u6001\u5b57\u6bb5&#xff09;\u7684\u526f\u672c&#xff0c;\u4f46\u5171\u4eab\u7c7b\u7684\u9759\u6001\u6210\u5458\u548c\u65b9\u6cd5\u4ee3\u7801\u3002<\/p>\n<p>\u5bf9\u8c61\u7684\u751f\u547d\u5468\u671f&#xff1a;<\/p>\n<li>\u521b\u5efa&#xff08;Creation&#xff09;&#xff1a;\u4f7f\u7528new\u5173\u952e\u5b57\u8c03\u7528\u6784\u9020\u5668\u3002<\/li>\n<li>\u4f7f\u7528&#xff08;Usage&#xff09;&#xff1a;\u901a\u8fc7\u5bf9\u8c61\u5f15\u7528\u6765\u8bbf\u95ee\u5176\u5b57\u6bb5&#xff08;\u901a\u8fc7getter\/setter&#xff09;\u548c\u8c03\u7528\u5176\u65b9\u6cd5\u3002<\/li>\n<li>\u9500\u6bc1&#xff08;Destruction&#xff09;&#xff1a;\u5f53\u5bf9\u8c61\u4e0d\u518d\u88ab\u4efb\u4f55\u5f15\u7528\u6307\u5411\u65f6&#xff0c;\u5b83\u6210\u4e3a\u5783\u573e&#xff08;Garbage&#xff09;&#xff0c;\u6700\u7ec8\u7531Java\u7684\u5783\u573e\u56de\u6536\u5668&#xff08;Garbage Collector, GC&#xff09;\u81ea\u52a8\u56de\u6536\u5185\u5b58\u3002<\/li>\n<h4>3.2 \u521b\u5efa\u5bf9\u8c61&#xff1a;new \u5173\u952e\u5b57<\/h4>\n<p>\u5728Java\u4e2d&#xff0c;\u521b\u5efa\u5bf9\u8c61\u7684\u6807\u51c6\u65b9\u5f0f\u662f\u4f7f\u7528new\u5173\u952e\u5b57&#xff0c;\u540e\u8ddf\u6784\u9020\u5668\u7684\u8c03\u7528\u3002<\/p>\n<p>\u8bed\u6cd5&#xff1a;<\/p>\n<p>\u7c7b\u540d \u5bf9\u8c61\u5f15\u7528\u540d <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> \u6784\u9020\u5668<span class=\"token punctuation\">(<\/span>\u53c2\u6570\u5217\u8868<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<ul>\n<li>\u7c7b\u540d&#xff1a;\u4f60\u8981\u521b\u5efa\u5b9e\u4f8b\u7684\u7c7b\u7684\u540d\u79f0\u3002<\/li>\n<li>\u5bf9\u8c61\u5f15\u7528\u540d&#xff1a;\u4e00\u4e2a\u53d8\u91cf&#xff0c;\u7528\u6765\u5b58\u50a8\u65b0\u521b\u5efa\u5bf9\u8c61\u7684\u5f15\u7528&#xff08;\u5185\u5b58\u5730\u5740&#xff09;\u3002\u8fd9\u4e2a\u53d8\u91cf\u7684\u7c7b\u578b\u5c31\u662f\u7c7b\u540d\u3002<\/li>\n<li>new&#xff1a;Java\u5173\u952e\u5b57&#xff0c;\u8d1f\u8d23\u5728\u5806\u5185\u5b58&#xff08;Heap Memory&#xff09;\u4e2d\u4e3a\u65b0\u5bf9\u8c61\u5206\u914d\u7a7a\u95f4\u3002<\/li>\n<li>\u6784\u9020\u5668(\u53c2\u6570\u5217\u8868)&#xff1a;\u8c03\u7528\u7c7b\u7684\u67d0\u4e2a\u6784\u9020\u5668\u6765\u521d\u59cb\u5316\u65b0\u5bf9\u8c61\u7684\u72b6\u6001\u3002\u53c2\u6570\u5217\u8868\u5fc5\u987b\u4e0e\u6240\u8c03\u7528\u7684\u6784\u9020\u5668\u7684\u53c2\u6570\u5339\u914d\u3002<\/li>\n<\/ul>\n<p>\u793a\u4f8b&#xff1a;\u521b\u5efa Person \u5bf9\u8c61<\/p>\n<p><span class=\"token keyword\">public<\/span> <span class=\"token keyword\">class<\/span> <span class=\"token class-name\">ObjectCreationDemo<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">static<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">main<\/span><span class=\"token punctuation\">(<\/span><span class=\"token class-name\">String<\/span><span class=\"token punctuation\">[<\/span><span class=\"token punctuation\">]<\/span> args<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token comment\">\/\/ 1. \u4f7f\u7528\u65e0\u53c2\u6784\u9020\u5668\u521b\u5efa\u5bf9\u8c61<\/span><br \/>\n        <span class=\"token class-name\">Person<\/span> person1 <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token comment\">\/\/ person1 \u662f\u4e00\u4e2a\u5f15\u7528\u53d8\u91cf&#xff0c;\u6307\u5411\u5806\u5185\u5b58\u4e2d\u521b\u5efa\u7684 Person \u5bf9\u8c61<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ 2. \u4f7f\u7528\u6709\u53c2\u6784\u9020\u5668\u521b\u5efa\u5bf9\u8c61<\/span><br \/>\n        <span class=\"token class-name\">Person<\/span> person2 <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Alice&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">25<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1.68<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">Person<\/span> person3 <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Bob&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">30<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1.75<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ 3. \u4f7f\u7528\u91cd\u8f7d\u7684\u6784\u9020\u5668\u521b\u5efa\u5bf9\u8c61<\/span><br \/>\n        <span class=\"token class-name\">Person<\/span> person4 <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Charlie&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">Person<\/span> person5 <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Diana&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">28<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ \u6253\u5370\u5bf9\u8c61&#xff08;\u4f1a\u81ea\u52a8\u8c03\u7528 toString() \u65b9\u6cd5&#xff09;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span>person1<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ Person{name&#061;&#039;\u672a\u77e5&#039;, age&#061;0, height&#061;0.0}<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span>person2<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ Person{name&#061;&#039;Alice&#039;, age&#061;25, height&#061;1.68}<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span>person3<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ Person{name&#061;&#039;Bob&#039;, age&#061;30, height&#061;1.75}<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span>person4<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ Person{name&#061;&#039;Charlie&#039;, age&#061;0, height&#061;0.0}<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span>person5<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ Person{name&#061;&#039;Diana&#039;, age&#061;28, height&#061;0.0}<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u5185\u5b58\u6a21\u578b\u7b80\u8ff0&#xff1a;<\/p>\n<ul>\n<li>Person person2 &#061; new Person(&#034;Alice&#034;, 25, 1.68);\n<ul>\n<li>\u53f3\u8fb9\u7684new Person(&#8230;)\u5728\u5806&#xff08;Heap&#xff09; \u5185\u5b58\u4e2d\u5206\u914d\u4e00\u5757\u7a7a\u95f4&#xff0c;\u5b58\u653ename, age, height\u8fd9\u4e09\u4e2a\u5b57\u6bb5\u7684\u5b9e\u9645\u503c&#xff08;\u201cAlice\u201d, 25, 1.68&#xff09;\u3002<\/li>\n<li>\u5de6\u8fb9\u7684Person person2\u5728\u6808&#xff08;Stack&#xff09; \u5185\u5b58\u4e2d\u521b\u5efa\u4e00\u4e2a\u540d\u4e3aperson2\u7684\u5f15\u7528\u53d8\u91cf\u3002<\/li>\n<li>&#061; \u64cd\u4f5c\u5c06\u5806\u4e2d\u5bf9\u8c61\u7684\u5185\u5b58\u5730\u5740&#xff08;\u5f15\u7528&#xff09;\u8d4b\u503c\u7ed9person2\u53d8\u91cf\u3002<\/li>\n<li>\u56e0\u6b64&#xff0c;person2\u8fd9\u4e2a\u53d8\u91cf\u5e76\u4e0d\u76f4\u63a5\u5b58\u50a8\u5bf9\u8c61\u7684\u6570\u636e&#xff0c;\u800c\u662f\u5b58\u50a8\u4e00\u4e2a\u6307\u5411\u5806\u4e2d\u5bf9\u8c61\u7684\u201c\u6307\u9488\u201d\u6216\u201c\u5f15\u7528\u201d\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h4>3.3 \u8bbf\u95ee\u5bf9\u8c61\u7684\u6210\u5458<\/h4>\n<p>\u4e00\u65e6\u521b\u5efa\u4e86\u5bf9\u8c61&#xff0c;\u5c31\u53ef\u4ee5\u901a\u8fc7\u5bf9\u8c61\u5f15\u7528\u6765\u8bbf\u95ee\u5176\u516c\u5f00\u7684\u6210\u5458&#xff08;\u5b57\u6bb5\u548c\u65b9\u6cd5&#xff09;\u3002\u7531\u4e8e\u6211\u4eec\u901a\u5e38\u5c06\u5b57\u6bb5\u8bbe\u4e3aprivate&#xff0c;\u6240\u4ee5\u4e3b\u8981\u901a\u8fc7getter\u548csetter\u65b9\u6cd5\u6765\u8bbf\u95ee\u548c\u4fee\u6539\u5b57\u6bb5&#xff0c;\u4ee5\u53ca\u8c03\u7528\u5bf9\u8c61\u7684\u884c\u4e3a\u65b9\u6cd5\u3002<\/p>\n<p>\u8bed\u6cd5&#xff1a;<\/p>\n<p>\u5bf9\u8c61\u5f15\u7528\u540d<span class=\"token punctuation\">.<\/span>\u6210\u5458\u540d<\/p>\n<p>\u793a\u4f8b&#xff1a;\u8bbf\u95ee Person \u5bf9\u8c61\u7684\u6210\u5458<\/p>\n<p><span class=\"token keyword\">public<\/span> <span class=\"token keyword\">class<\/span> <span class=\"token class-name\">ObjectAccessDemo<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">static<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">main<\/span><span class=\"token punctuation\">(<\/span><span class=\"token class-name\">String<\/span><span class=\"token punctuation\">[<\/span><span class=\"token punctuation\">]<\/span> args<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token comment\">\/\/ \u521b\u5efa\u5bf9\u8c61<\/span><br \/>\n        <span class=\"token class-name\">Person<\/span> alice <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Alice&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">25<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1.68<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ &#8212; \u8bbf\u95ee&#xff08;\u8bfb\u53d6&#xff09;\u5b57\u6bb5\u503c &#8212;<\/span><br \/>\n        <span class=\"token comment\">\/\/ \u901a\u8fc7 getter \u65b9\u6cd5<\/span><br \/>\n        <span class=\"token class-name\">String<\/span> name <span class=\"token operator\">&#061;<\/span> alice<span class=\"token punctuation\">.<\/span><span class=\"token function\">getName<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">int<\/span> age <span class=\"token operator\">&#061;<\/span> alice<span class=\"token punctuation\">.<\/span><span class=\"token function\">getAge<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token keyword\">double<\/span> height <span class=\"token operator\">&#061;<\/span> alice<span class=\"token punctuation\">.<\/span><span class=\"token function\">getHeight<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span>name <span class=\"token operator\">&#043;<\/span> <span class=\"token string\">&#034; is &#034;<\/span> <span class=\"token operator\">&#043;<\/span> age <span class=\"token operator\">&#043;<\/span> <span class=\"token string\">&#034; years old and &#034;<\/span> <span class=\"token operator\">&#043;<\/span> height <span class=\"token operator\">&#043;<\/span> <span class=\"token string\">&#034;m tall.&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ &#8212; \u4fee\u6539&#xff08;\u8bbe\u7f6e&#xff09;\u5b57\u6bb5\u503c &#8212;<\/span><br \/>\n        <span class=\"token comment\">\/\/ \u901a\u8fc7 setter \u65b9\u6cd5<\/span><br \/>\n        alice<span class=\"token punctuation\">.<\/span><span class=\"token function\">setAge<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">26<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u751f\u65e5\u8fc7\u4e86&#xff0c;\u5e74\u9f84\u589e\u52a0<\/span><br \/>\n        alice<span class=\"token punctuation\">.<\/span><span class=\"token function\">setHeight<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1.69<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u957f\u9ad8\u4e86\u4e00\u70b9\u70b9&#xff08;\u5f00\u73a9\u7b11&#xff09;<\/span><br \/>\n        <span class=\"token comment\">\/\/ alice.setName(&#034;&#034;); \/\/ \u4f1a\u8f93\u51fa\u9519\u8bef\u4fe1\u606f&#xff0c;\u56e0\u4e3asetter\u4e2d\u6709\u9a8c\u8bc1<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ \u518d\u6b21\u6253\u5370\u67e5\u770b\u53d8\u5316<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span>alice<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ Person{name&#061;&#039;Alice&#039;, age&#061;26, height&#061;1.69}<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ &#8212; \u8c03\u7528\u5bf9\u8c61\u7684\u884c\u4e3a\u65b9\u6cd5 &#8212;<\/span><br \/>\n        alice<span class=\"token punctuation\">.<\/span><span class=\"token function\">walk<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ Alice \u6b63\u5728\u8d70\u8def\u3002<\/span><br \/>\n        alice<span class=\"token punctuation\">.<\/span><span class=\"token function\">talk<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Hello, everyone!&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ Alice \u8bf4: &#034;Hello, everyone!&#034;<\/span><br \/>\n        alice<span class=\"token punctuation\">.<\/span><span class=\"token function\">eat<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;an apple&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ Alice \u6b63\u5728\u5403 an apple\u3002<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u5173\u952e\u70b9&#xff1a;<\/p>\n<ul>\n<li>alice.getName()&#xff1a;\u8c03\u7528alice\u5bf9\u8c61\u7684getName()\u65b9\u6cd5&#xff0c;\u8fd4\u56de\u5176name\u5b57\u6bb5\u7684\u503c\u3002<\/li>\n<li>alice.setAge(26)&#xff1a;\u8c03\u7528alice\u5bf9\u8c61\u7684setAge()\u65b9\u6cd5&#xff0c;\u5c06age\u5b57\u6bb5\u8bbe\u7f6e\u4e3a26\u3002<\/li>\n<li>alice.walk()&#xff1a;\u8c03\u7528alice\u5bf9\u8c61\u7684walk()\u65b9\u6cd5&#xff0c;\u6267\u884c\u884c\u8d70\u7684\u52a8\u4f5c\u3002<\/li>\n<li>\u5c01\u88c5\u7684\u4f53\u73b0&#xff1a;\u6211\u4eec\u65e0\u6cd5\u76f4\u63a5\u5199alice.age &#061; 26;&#xff08;\u56e0\u4e3aage\u662fprivate&#xff09;&#xff0c;\u5fc5\u987b\u901a\u8fc7setAge()\u65b9\u6cd5\u3002\u8fd9\u4f7f\u5f97\u6211\u4eec\u53ef\u4ee5\u5728setAge()\u65b9\u6cd5\u4e2d\u52a0\u5165\u903b\u8f91&#xff08;\u5982\u5e74\u9f84\u8303\u56f4\u68c0\u67e5&#xff09;&#xff0c;\u786e\u4fdd\u6570\u636e\u7684\u6709\u6548\u6027\u3002<\/li>\n<\/ul>\n<h4>3.4 \u591a\u4e2a\u5bf9\u8c61\u4e0e\u72ec\u7acb\u72b6\u6001<\/h4>\n<p>\u6bcf\u4e2a\u5bf9\u8c61\u90fd\u6709\u81ea\u5df1\u72ec\u7acb\u7684\u5b9e\u4f8b\u5b57\u6bb5\u526f\u672c\u3002\u4fee\u6539\u4e00\u4e2a\u5bf9\u8c61\u7684\u72b6\u6001\u4e0d\u4f1a\u5f71\u54cd\u5176\u4ed6\u5bf9\u8c61\u3002<\/p>\n<p>\u793a\u4f8b&#xff1a;\u591a\u4e2a Person \u5bf9\u8c61<\/p>\n<p><span class=\"token keyword\">public<\/span> <span class=\"token keyword\">class<\/span> <span class=\"token class-name\">MultipleObjectsDemo<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">static<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">main<\/span><span class=\"token punctuation\">(<\/span><span class=\"token class-name\">String<\/span><span class=\"token punctuation\">[<\/span><span class=\"token punctuation\">]<\/span> args<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token class-name\">Person<\/span> personA <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Alice&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">25<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1.68<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">Person<\/span> personB <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Bob&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">30<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1.75<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\u521b\u5efa\u65f6:&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Person A: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> personA<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Person B: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> personB<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ \u4fee\u6539 personA \u7684\u5e74\u9f84<\/span><br \/>\n        personA<span class=\"token punctuation\">.<\/span><span class=\"token function\">setAge<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">26<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token comment\">\/\/ \u4fee\u6539 personB \u7684\u8eab\u9ad8<\/span><br \/>\n        personB<span class=\"token punctuation\">.<\/span><span class=\"token function\">setHeight<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">1.76<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\\\\n\u4fee\u6539\u540e:&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Person A: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> personA<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ age \u53d8\u4e3a 26<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Person B: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> personB<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ height \u53d8\u4e3a 1.76<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ \u9759\u6001\u6210\u5458\u662f\u5171\u4eab\u7684<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\u603b\u4eba\u6570: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">.<\/span><span class=\"token function\">getTotalPersonCount<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ 2<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u8f93\u51fa&#xff1a;<\/p>\n<p>\u521b\u5efa\u65f6:<br \/>\nPerson A: Person{name&#061;&#039;Alice&#039;, age&#061;25, height&#061;1.68}<br \/>\nPerson B: Person{name&#061;&#039;Bob&#039;, age&#061;30, height&#061;1.75}<\/p>\n<p>\u4fee\u6539\u540e:<br \/>\nPerson A: Person{name&#061;&#039;Alice&#039;, age&#061;26, height&#061;1.68}<br \/>\nPerson B: Person{name&#061;&#039;Bob&#039;, age&#061;30, height&#061;1.76}<br \/>\n\u603b\u4eba\u6570: 2<\/p>\n<p>\u5206\u6790&#xff1a;<\/p>\n<ul>\n<li>personA\u548cpersonB\u662f\u4e24\u4e2a\u72ec\u7acb\u7684\u5bf9\u8c61\u3002<\/li>\n<li>\u4fee\u6539personA\u7684age\u53ea\u5f71\u54cdpersonA&#xff0c;personB\u7684age\u4ecd\u7136\u662f30\u3002<\/li>\n<li>\u540c\u6837&#xff0c;\u4fee\u6539personB\u7684height\u53ea\u5f71\u54cdpersonB\u3002<\/li>\n<li>\u9759\u6001\u5b57\u6bb5totalPersonCount\u662f\u5171\u4eab\u7684&#xff0c;\u521b\u5efa\u4e24\u4e2a\u5bf9\u8c61\u540e\u5176\u503c\u4e3a2\u3002<\/li>\n<\/ul>\n<h4>3.5 \u5bf9\u8c61\u5f15\u7528\u4e0e\u8d4b\u503c<\/h4>\n<p>\u7406\u89e3\u5bf9\u8c61\u5f15\u7528\u662f\u638c\u63e1Java\u5185\u5b58\u6a21\u578b\u7684\u5173\u952e\u3002<\/p>\n<p>\u5bf9\u8c61\u5f15\u7528\u8d4b\u503c&#xff1a;<\/p>\n<p><span class=\"token class-name\">Person<\/span> person1 <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Alice&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">25<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1.68<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token class-name\">Person<\/span> person2 <span class=\"token operator\">&#061;<\/span> person1<span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u5c06 person1 \u7684\u5f15\u7528\u8d4b\u503c\u7ed9 person2<\/span><\/p>\n<p>\u6b64\u65f6&#xff0c;person1\u548cperson2\u90fd\u6307\u5411\u540c\u4e00\u4e2aPerson\u5bf9\u8c61&#xff08;\u5728\u5806\u5185\u5b58\u4e2d\u7684\u540c\u4e00\u4e2a\u4f4d\u7f6e&#xff09;\u3002\u5b83\u4eec\u662f\u540c\u4e00\u4e2a\u5bf9\u8c61\u7684\u4e24\u4e2a\u201c\u522b\u540d\u201d\u3002<\/p>\n<p>\u793a\u4f8b&#xff1a;\u5f15\u7528\u8d4b\u503c\u7684\u5f71\u54cd<\/p>\n<p><span class=\"token keyword\">public<\/span> <span class=\"token keyword\">class<\/span> <span class=\"token class-name\">ReferenceAssignmentDemo<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">static<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">main<\/span><span class=\"token punctuation\">(<\/span><span class=\"token class-name\">String<\/span><span class=\"token punctuation\">[<\/span><span class=\"token punctuation\">]<\/span> args<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token class-name\">Person<\/span> alice1 <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Alice&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">25<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1.68<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">Person<\/span> alice2 <span class=\"token operator\">&#061;<\/span> alice1<span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ alice2 \u6307\u5411 alice1 \u6240\u6307\u5411\u7684\u540c\u4e00\u4e2a\u5bf9\u8c61<\/span><\/p>\n<p>        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\u521d\u59cb\u72b6\u6001:&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;alice1: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> alice1<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;alice2: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> alice2<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ \u901a\u8fc7 alice2 \u4fee\u6539\u5bf9\u8c61<\/span><br \/>\n        alice2<span class=\"token punctuation\">.<\/span><span class=\"token function\">setAge<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">26<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        alice2<span class=\"token punctuation\">.<\/span><span class=\"token function\">setName<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Alice Smith&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;\\\\n\u901a\u8fc7 alice2 \u4fee\u6539\u540e:&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;alice1: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> alice1<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ alice1 \u7684\u72b6\u6001\u4e5f\u53d8\u4e86&#xff01;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;alice2: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> alice2<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token comment\">\/\/ \u6bd4\u8f83\u5f15\u7528<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;alice1 &#061;&#061; alice2: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> <span class=\"token punctuation\">(<\/span>alice1 <span class=\"token operator\">&#061;&#061;<\/span> alice2<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ true (\u5f15\u7528\u76f8\u7b49)<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u8f93\u51fa&#xff1a;<\/p>\n<p>\u521d\u59cb\u72b6\u6001:<br \/>\nalice1: Person{name&#061;&#039;Alice&#039;, age&#061;25, height&#061;1.68}<br \/>\nalice2: Person{name&#061;&#039;Alice&#039;, age&#061;25, height&#061;1.68}<\/p>\n<p>\u901a\u8fc7 alice2 \u4fee\u6539\u540e:<br \/>\nalice1: Person{name&#061;&#039;Alice Smith&#039;, age&#061;26, height&#061;1.68}<br \/>\nalice2: Person{name&#061;&#039;Alice Smith&#039;, age&#061;26, height&#061;1.68}<br \/>\nalice1 &#061;&#061; alice2: true<\/p>\n<p>\u5173\u952e\u70b9&#xff1a;<\/p>\n<ul>\n<li>alice1 &#061;&#061; alice2 \u8fd4\u56detrue&#xff0c;\u56e0\u4e3a\u5b83\u4eec\u5f15\u7528\u7684\u662f\u5806\u5185\u5b58\u4e2d\u7684\u540c\u4e00\u4e2a\u5bf9\u8c61\u3002<\/li>\n<li>\u901a\u8fc7alice2\u4fee\u6539\u5bf9\u8c61\u7684\u72b6\u6001&#xff0c;alice1\u770b\u5230\u7684\u4e5f\u662f\u4fee\u6539\u540e\u7684\u72b6\u6001&#xff0c;\u56e0\u4e3a\u5b83\u4eec\u662f\u540c\u4e00\u4e2a\u5bf9\u8c61\u3002<\/li>\n<\/ul>\n<p>\u521b\u5efa\u72ec\u7acb\u7684\u526f\u672c&#xff1a;<\/p>\n<p>\u5982\u679c\u4f60\u60f3\u521b\u5efa\u4e00\u4e2a\u5177\u6709\u76f8\u540c\u521d\u59cb\u72b6\u6001\u4f46\u5b8c\u5168\u72ec\u7acb\u7684\u5bf9\u8c61&#xff0c;\u4f60\u9700\u8981\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u5b9e\u4f8b\u3002<\/p>\n<p><span class=\"token class-name\">Person<\/span> alice1 <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Alice&#034;<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">25<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1.68<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token class-name\">Person<\/span> alice3 <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">Person<\/span><span class=\"token punctuation\">(<\/span>alice1<span class=\"token punctuation\">.<\/span><span class=\"token function\">getName<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> alice1<span class=\"token punctuation\">.<\/span><span class=\"token function\">getAge<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> alice1<span class=\"token punctuation\">.<\/span><span class=\"token function\">getHeight<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token comment\">\/\/ \u6216\u8005\u4f7f\u7528\u590d\u5236\u6784\u9020\u5668&#xff08;\u5982\u679c\u7c7b\u4e2d\u5b9a\u4e49\u4e86\u7684\u8bdd&#xff09;<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u73b0\u5728 alice1 \u548c alice3 \u662f\u4e24\u4e2a\u72ec\u7acb\u7684\u5bf9\u8c61<\/span><br \/>\nalice3<span class=\"token punctuation\">.<\/span><span class=\"token function\">setAge<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">30<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;alice1: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> alice1<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ age \u4ecd\u7136\u662f 25<\/span><br \/>\n<span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;alice3: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> alice3<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ age \u662f 30<\/span><br \/>\n<span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;alice1 &#061;&#061; alice3: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> <span class=\"token punctuation\">(<\/span>alice1 <span class=\"token operator\">&#061;&#061;<\/span> alice3<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ false<\/span><\/p>\n<hr \/>\n<h3>\u7b2c\u56db\u7ae0&#xff1a;\u6df1\u5165\u7406\u89e3\u5c01\u88c5\u4e0e\u8bbf\u95ee\u63a7\u5236<\/h3>\n<p>\u5c01\u88c5\u662f\u9762\u5411\u5bf9\u8c61\u7f16\u7a0b\u7684\u6838\u5fc3\u539f\u5219\u4e4b\u4e00&#xff0c;\u5b83\u901a\u8fc7\u9690\u85cf\u5bf9\u8c61\u7684\u5185\u90e8\u5b9e\u73b0\u7ec6\u8282&#xff0c;\u4ec5\u66b4\u9732\u5fc5\u8981\u7684\u63a5\u53e3\u6765\u4e0e\u5916\u754c\u4ea4\u4e92&#xff0c;\u4ece\u800c\u4fdd\u62a4\u6570\u636e\u7684\u5b8c\u6574\u6027\u548c\u5b89\u5168\u6027\u3002Java\u901a\u8fc7\u8bbf\u95ee\u4fee\u9970\u7b26&#xff08;Access Modifiers&#xff09; \u6765\u5b9e\u73b0\u5c01\u88c5\u3002<\/p>\n<h4>4.1 \u8bbf\u95ee\u4fee\u9970\u7b26\u8be6\u89e3<\/h4>\n<p>Java\u63d0\u4f9b\u4e86\u56db\u79cd\u8bbf\u95ee\u7ea7\u522b&#xff0c;\u4ece\u6700\u5bbd\u677e\u5230\u6700\u4e25\u683c&#xff1a;<\/p>\n<table>\n<tr>\u4fee\u9970\u7b26\u540c\u4e00\u7c7b\u540c\u4e00\u5305\u5b50\u7c7b\u4e0d\u540c\u5305\u7684\u975e\u5b50\u7c7b\u8bf4\u660e<\/tr>\n<tbody>\n<tr>\n<td align=\"left\">public<\/td>\n<td align=\"left\">\u2705<\/td>\n<td align=\"left\">\u2705<\/td>\n<td align=\"left\">\u2705<\/td>\n<td align=\"left\">\u2705<\/td>\n<td align=\"left\">\u65e0\u9650\u5236&#xff0c;\u4efb\u4f55\u5730\u65b9\u90fd\u53ef\u8bbf\u95ee\u3002<\/td>\n<\/tr>\n<tr>\n<td align=\"left\">protected<\/td>\n<td align=\"left\">\u2705<\/td>\n<td align=\"left\">\u2705<\/td>\n<td align=\"left\">\u2705<\/td>\n<td align=\"left\">\u274c<\/td>\n<td align=\"left\">\u540c\u4e00\u7c7b\u3001\u540c\u4e00\u5305\u3001\u5b50\u7c7b&#xff08;\u5373\u4f7f\u5b50\u7c7b\u5728\u4e0d\u540c\u5305&#xff09;\u53ef\u8bbf\u95ee\u3002<\/td>\n<\/tr>\n<tr>\n<td align=\"left\">(\u9ed8\u8ba4&#xff0c;\u65e0\u5173\u952e\u5b57)<\/td>\n<td align=\"left\">\u2705<\/td>\n<td align=\"left\">\u2705<\/td>\n<td align=\"left\">\u274c<\/td>\n<td align=\"left\">\u274c<\/td>\n<td align=\"left\">\u4ec5\u5728\u540c\u4e00\u5305\u5185\u53ef\u8bbf\u95ee&#xff08;\u5305\u8bbf\u95ee\u6743\u9650&#xff09;\u3002<\/td>\n<\/tr>\n<tr>\n<td align=\"left\">private<\/td>\n<td align=\"left\">\u2705<\/td>\n<td align=\"left\">\u274c<\/td>\n<td align=\"left\">\u274c<\/td>\n<td align=\"left\">\u274c<\/td>\n<td align=\"left\">\u4ec5\u5728\u672c\u7c7b\u5185\u90e8\u53ef\u8bbf\u95ee\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u793a\u4f8b&#xff1a;\u6f14\u793a\u4e0d\u540c\u8bbf\u95ee\u4fee\u9970\u7b26\u7684\u4f5c\u7528<\/p>\n<p><span class=\"token comment\">\/\/ \u6587\u4ef6: AccessDemo.java<\/span><br \/>\n<span class=\"token keyword\">package<\/span> <span class=\"token namespace\">com<span class=\"token punctuation\">.<\/span>example<span class=\"token punctuation\">.<\/span>access<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u57fa\u7c7b<\/span><br \/>\n<span class=\"token keyword\">class<\/span> <span class=\"token class-name\">BaseClass<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token class-name\">String<\/span> publicField <span class=\"token operator\">&#061;<\/span> <span class=\"token string\">&#034;public&#034;<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token keyword\">protected<\/span> <span class=\"token class-name\">String<\/span> protectedField <span class=\"token operator\">&#061;<\/span> <span class=\"token string\">&#034;protected&#034;<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token class-name\">String<\/span> defaultField <span class=\"token operator\">&#061;<\/span> <span class=\"token string\">&#034;default&#034;<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ \u5305\u8bbf\u95ee\u6743\u9650<\/span><br \/>\n    <span class=\"token keyword\">private<\/span> <span class=\"token class-name\">String<\/span> privateField <span class=\"token operator\">&#061;<\/span> <span class=\"token string\">&#034;private&#034;<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">publicMethod<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;BaseClass.publicMethod()&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token comment\">\/\/ \u5728\u7c7b\u5185\u90e8&#xff0c;\u53ef\u4ee5\u8bbf\u95ee\u6240\u6709\u6210\u5458<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span>privateField<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token keyword\">protected<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">protectedMethod<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;BaseClass.protectedMethod()&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token keyword\">void<\/span> <span class=\"token function\">defaultMethod<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span> <span class=\"token comment\">\/\/ \u5305\u8bbf\u95ee\u6743\u9650<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;BaseClass.defaultMethod()&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token keyword\">private<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">privateMethod<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;BaseClass.privateMethod()&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><\/p>\n<p>    <span class=\"token comment\">\/\/ \u4e00\u4e2a\u65b9\u6cd5\u7528\u4e8e\u5c55\u793a\u5185\u90e8\u8bbf\u95ee<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">demonstrateInternalAccess<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;&#061;&#061;&#061; BaseClass \u5185\u90e8\u8bbf\u95ee &#061;&#061;&#061;&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;publicField: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> publicField<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;protectedField: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> protectedField<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;defaultField: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> defaultField<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;privateField: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> privateField<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token function\">privateMethod<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u540c\u4e00\u5305\u5185\u7684\u53e6\u4e00\u4e2a\u7c7b<\/span><br \/>\n<span class=\"token keyword\">class<\/span> <span class=\"token class-name\">SamePackageClass<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">accessBase<\/span><span class=\"token punctuation\">(<\/span><span class=\"token class-name\">BaseClass<\/span> base<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;&#061;&#061;&#061; SamePackageClass \u8bbf\u95ee BaseClass &#061;&#061;&#061;&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;publicField: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> base<span class=\"token punctuation\">.<\/span>publicField<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;protectedField: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> base<span class=\"token punctuation\">.<\/span>protectedField<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;defaultField: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> base<span class=\"token punctuation\">.<\/span>defaultField<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n        <span class=\"token comment\">\/\/ System.out.println(base.privateField); \/\/ \u7f16\u8bd1\u9519\u8bef&#xff01;<\/span><br \/>\n        base<span class=\"token punctuation\">.<\/span><span class=\"token function\">publicMethod<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n        base<span class=\"token punctuation\">.<\/span><span class=\"token function\">protectedMethod<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n        base<span class=\"token punctuation\">.<\/span><span class=\"token function\">defaultMethod<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n        <span class=\"token comment\">\/\/ base.privateMethod(); \/\/ \u7f16\u8bd1\u9519\u8bef&#xff01;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u540c\u4e00\u5305\u5185\u7684\u5b50\u7c7b<\/span><br \/>\n<span class=\"token keyword\">class<\/span> <span class=\"token class-name\">SubClassInSamePackage<\/span> <span class=\"token keyword\">extends<\/span> <span class=\"token class-name\">BaseClass<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">accessFromSubClass<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;&#061;&#061;&#061; SubClassInSamePackage \u8bbf\u95ee &#061;&#061;&#061;&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;publicField: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> publicField<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;protectedField: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> protectedField<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;defaultField: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> defaultField<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n        <span class=\"token comment\">\/\/ System.out.println(privateField); \/\/ \u7f16\u8bd1\u9519\u8bef&#xff01;<\/span><br \/>\n        <span class=\"token function\">publicMethod<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n        <span class=\"token function\">protectedMethod<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n        <span class=\"token function\">defaultMethod<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n        <span class=\"token comment\">\/\/ privateMethod(); \/\/ \u7f16\u8bd1\u9519\u8bef&#xff01;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u4e3b\u7c7b\u7528\u4e8e\u6d4b\u8bd5<\/span><br \/>\n<span class=\"token keyword\">public<\/span> <span class=\"token keyword\">class<\/span> <span class=\"token class-name\">AccessDemo<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">static<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">main<\/span><span class=\"token punctuation\">(<\/span><span class=\"token class-name\">String<\/span><span class=\"token punctuation\">[<\/span><span class=\"token punctuation\">]<\/span> args<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token class-name\">BaseClass<\/span> base <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">BaseClass<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        base<span class=\"token punctuation\">.<\/span><span class=\"token function\">demonstrateInternalAccess<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token class-name\">SamePackageClass<\/span> samePkg <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">SamePackageClass<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        samePkg<span class=\"token punctuation\">.<\/span><span class=\"token function\">accessBase<\/span><span class=\"token punctuation\">(<\/span>base<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p>        <span class=\"token class-name\">SubClassInSamePackage<\/span> sub <span class=\"token operator\">&#061;<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">SubClassInSamePackage<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        sub<span class=\"token punctuation\">.<\/span><span class=\"token function\">accessFromSubClass<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u8f93\u51fa\u5206\u6790&#xff1a;<\/p>\n<ul>\n<li>BaseClass\u5185\u90e8\u53ef\u4ee5\u8bbf\u95ee\u6240\u6709\u6210\u5458\u3002<\/li>\n<li>SamePackageClass&#xff08;\u540c\u5305&#xff09;\u53ef\u4ee5\u8bbf\u95eepublic, protected, \u548cdefault\u6210\u5458&#xff0c;\u4f46\u4e0d\u80fd\u8bbf\u95eeprivate\u6210\u5458\u3002<\/li>\n<li>SubClassInSamePackage&#xff08;\u540c\u5305\u5b50\u7c7b&#xff09;\u7684\u8bbf\u95ee\u6743\u9650\u4e0eSamePackageClass\u76f8\u540c\u3002<\/li>\n<\/ul>\n<p>\u8de8\u5305\u793a\u4f8b&#xff1a;<\/p>\n<p><span class=\"token comment\">\/\/ \u6587\u4ef6: DifferentPackageClass.java<\/span><br \/>\n<span class=\"token keyword\">package<\/span> <span class=\"token namespace\">com<span class=\"token punctuation\">.<\/span>example<span class=\"token punctuation\">.<\/span>other<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token keyword\">import<\/span> <span class=\"token namespace\">com<span class=\"token punctuation\">.<\/span>example<span class=\"token punctuation\">.<\/span>access<span class=\"token punctuation\">.<\/span><\/span><span class=\"token class-name\">BaseClass<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u4e0d\u540c\u5305\u7684\u975e\u5b50\u7c7b<\/span><br \/>\n<span class=\"token keyword\">public<\/span> <span class=\"token keyword\">class<\/span> <span class=\"token class-name\">DifferentPackageClass<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">accessBase<\/span><span class=\"token punctuation\">(<\/span><span class=\"token class-name\">BaseClass<\/span> base<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;&#061;&#061;&#061; DifferentPackageClass \u8bbf\u95ee BaseClass &#061;&#061;&#061;&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;publicField: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> base<span class=\"token punctuation\">.<\/span>publicField<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n        <span class=\"token comment\">\/\/ System.out.println(base.protectedField); \/\/ \u7f16\u8bd1\u9519\u8bef&#xff01;<\/span><br \/>\n        <span class=\"token comment\">\/\/ System.out.println(base.defaultField); \/\/ \u7f16\u8bd1\u9519\u8bef&#xff01;<\/span><br \/>\n        <span class=\"token comment\">\/\/ System.out.println(base.privateField); \/\/ \u7f16\u8bd1\u9519\u8bef&#xff01;<\/span><br \/>\n        base<span class=\"token punctuation\">.<\/span><span class=\"token function\">publicMethod<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n        <span class=\"token comment\">\/\/ base.protectedMethod(); \/\/ \u7f16\u8bd1\u9519\u8bef&#xff01;<\/span><br \/>\n        <span class=\"token comment\">\/\/ base.defaultMethod(); \/\/ \u7f16\u8bd1\u9519\u8bef&#xff01;<\/span><br \/>\n        <span class=\"token comment\">\/\/ base.privateMethod(); \/\/ \u7f16\u8bd1\u9519\u8bef&#xff01;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u6587\u4ef6: DifferentPackageSubClass.java<\/span><br \/>\n<span class=\"token keyword\">package<\/span> <span class=\"token namespace\">com<span class=\"token punctuation\">.<\/span>example<span class=\"token punctuation\">.<\/span>other<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token keyword\">import<\/span> <span class=\"token namespace\">com<span class=\"token punctuation\">.<\/span>example<span class=\"token punctuation\">.<\/span>access<span class=\"token punctuation\">.<\/span><\/span><span class=\"token class-name\">BaseClass<\/span><span class=\"token punctuation\">;<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u4e0d\u540c\u5305\u7684\u5b50\u7c7b<\/span><br \/>\n<span class=\"token keyword\">public<\/span> <span class=\"token keyword\">class<\/span> <span class=\"token class-name\">DifferentPackageSubClass<\/span> <span class=\"token keyword\">extends<\/span> <span class=\"token class-name\">BaseClass<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">public<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">accessFromSubClass<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;&#061;&#061;&#061; DifferentPackageSubClass \u8bbf\u95ee &#061;&#061;&#061;&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;publicField: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> publicField<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n        <span class=\"token class-name\">System<\/span><span class=\"token punctuation\">.<\/span>out<span class=\"token punctuation\">.<\/span><span class=\"token function\">println<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;protectedField: &#034;<\/span> <span class=\"token operator\">&#043;<\/span> protectedField<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK (\u5b50\u7c7b\u7279\u6743)<\/span><br \/>\n        <span class=\"token comment\">\/\/ System.out.println(defaultField); \/\/ \u7f16\u8bd1\u9519\u8bef&#xff01; (\u4e0d\u540c\u5305)<\/span><br \/>\n        <span class=\"token comment\">\/\/ System.out.println(privateField); \/\/ \u7f16\u8bd1\u9519\u8bef&#xff01;<\/span><br \/>\n        <span class=\"token function\">publicMethod<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK<\/span><br \/>\n        <span class=\"token function\">protectedMethod<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ OK (\u5b50\u7c7b\u7279\u6743)<\/span><br \/>\n        <span class=\"token comment\">\/\/ defaultMethod(); \/\/ \u7f16\u8bd1\u9519\u8bef&#xff01; (\u4e0d\u540c\u5305)<\/span><br \/>\n        <span class=\"token comment\">\/\/ privateMethod(); \/\/ \u7f16\u8bd1\u9519\u8bef&#xff01;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<p>\u5173\u952e\u70b9&#xff1a;<\/p>\n<ul>\n<li>DifferentPackageClass\u53ea\u80fd\u8bbf\u95eeBaseClass\u7684public\u6210\u5458\u3002<\/li>\n<li>DifferentPackageSubClass\u4f5c\u4e3a\u5b50\u7c7b&#xff0c;\u53ef\u4ee5\u8bbf\u95eepublic\u548cprotected\u6210\u5458&#xff0c;\u4f46\u4e0d\u80fd\u8bbf\u95eedefault&#xff08;\u5305\u8bbf\u95ee\u6743\u9650&#xff09;\u6210\u5458\u3002<\/li>\n<\/ul>\n<h4>4.2 \u5c01\u88c5\u7684\u5b9e\u8df5&#xff1a;\u4e3a\u4ec0\u4e48\u4f7f\u7528 getter \u548c setter&#xff1f;<\/h4>\n<p>\u76f4\u63a5\u5c06\u5b57\u6bb5\u8bbe\u4e3apublic\u867d\u7136\u7b80\u5355&#xff0c;\u4f46\u7834\u574f\u4e86\u5c01\u88c5\u6027\u3002\u4f7f\u7528private\u5b57\u6bb5\u914d\u5408public getter\u548csetter\u65b9\u6cd5\u662f\u6807\u51c6\u505a\u6cd5&#xff0c;\u539f\u56e0\u5982\u4e0b&#xff1a;<\/p>\n<li>\u6570\u636e\u9a8c\u8bc1&#xff08;Data Validation&#xff09;&#xff1a;\u5728setter\u65b9\u6cd5\u4e2d\u53ef\u4ee5\u52a0\u5165\u903b\u8f91&#xff0c;\u786e\u4fdd\u6570\u636e\u7684\u6709\u6548\u6027\u3002<span class=\"token keyword\">public<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">setAge<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">int<\/span> age<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>age <span class=\"token operator\">&lt;<\/span> <span class=\"token number\">0<\/span> <span class=\"token operator\">||<\/span> age <span class=\"token operator\">&gt;<\/span> <span class=\"token number\">150<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        <span class=\"token keyword\">throw<\/span> <span class=\"token keyword\">new<\/span> <span class=\"token class-name\">IllegalArgumentException<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Age must be between 0 and 150.&#034;<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n    <span class=\"token punctuation\">}<\/span><br \/>\n    <span class=\"token keyword\">this<\/span><span class=\"token punctuation\">.<\/span>age <span class=\"token operator\">&#061;<\/span> age<span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span><\/p>\n<\/li>\n<li>\u63a7\u5236\u8bbf\u95ee&#xff08;Controlled Access&#xff09;&#xff1a;\u53ef\u4ee5\u53ea\u63d0\u4f9bgetter&#xff08;\u53ea\u8bfb&#xff09;\u6216\u53ea\u63d0\u4f9bsetter&#xff08;\u53ea\u5199&#xff09;&#xff0c;\u6216\u8005\u5bf9\u8bfb\u5199\u65bd\u52a0\u4e0d\u540c\u7684\u6761\u4ef6\u3002<span class=\"token comment\">\/\/ \u53ea\u8bfb\u5b57\u6bb5<\/span><br \/>\n<span class=\"token keyword\">private<\/span> <span class=\"token keyword\">final<\/span> <span class=\"token class-name\">String<\/span> id<span class=\"token punctuation\">;<\/span> <span class=\"token comment\">\/\/ final \u8868\u793a\u4e0d\u53ef\u53d8<\/span><br \/>\n<span class=\"token keyword\">public<\/span> <span class=\"token class-name\">String<\/span> <span class=\"token function\">getId<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span> <span class=\"token keyword\">return<\/span> id<span class=\"token punctuation\">;<\/span> <span class=\"token punctuation\">}<\/span> <span class=\"token comment\">\/\/ \u53ea\u6709 getter<\/span><\/p>\n<p><span class=\"token comment\">\/\/ \u53ea\u5199\u5b57\u6bb5&#xff08;\u8f83\u5c11\u89c1&#xff09;<\/span><br \/>\n<span class=\"token keyword\">private<\/span> <span class=\"token class-name\">String<\/span> passwordHash<span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token keyword\">public<\/span> <span class=\"token keyword\">void<\/span> <span class=\"token function\">setPassword<\/span><span class=\"token punctuation\">(<\/span><span class=\"token class-name\">String<\/span> password<span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">this<\/span><span class=\"token punctuation\">.<\/span>passwordHash <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">hashPassword<\/span><span class=\"token punctuation\">(<\/span>password<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token punctuation\">}<\/span> <span class=\"token comment\">\/\/ \u53ea\u6709 setter<\/span><\/p>\n<\/li>\n<li>\u5ef6\u8fdf\u521d\u59cb\u5316&#xff08;Lazy Initialization&#xff09;&#xff1a;getter\u65b9\u6cd5\u53ef\u4ee5\u5728\u7b2c\u4e00\u6b21\u8bbf\u95ee\u65f6\u624d\u8ba1\u7b97\u6216\u52a0\u8f7d\u6570\u636e\u3002<span class=\"token keyword\">private<\/span> <span class=\"token class-name\">ExpensiveObject<\/span> expensiveObject<span class=\"token punctuation\">;<\/span><br \/>\n<span class=\"token keyword\">public<\/span> <span class=\"token class-name\">ExpensiveObject<\/span> <span class=\"token function\">getExpensiveObject<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n    <span class=\"token keyword\">if<\/span> <span class=\"token punctuation\">(<\/span>expensiveObject <span class=\"token operator\">&#061;&#061;<\/span> <span class=\"token keyword\">null<\/span><span class=\"token punctuation\">)<\/span> <span class=\"token punctuation\">{<\/span><br \/>\n        expensiveObject <span class=\"token operator\">&#061;<\/span> <span class=\"token function\">loadExpensiveObject<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span> <span class=\"token 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