![\"menu-r.4af5f7ec.gif\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250516174557-682779d53705b.gif\")
<\/p>\n \u672c\u6587\u8fd8\u6709\u914d\u5957\u7684\u7cbe\u54c1\u8d44\u6e90，\u70b9\u51fb\u83b7\u53d6 <\/p>\n
\u7b80\u4ecb：Java NIO\u662f\u81ea1.4\u7248\u672c\u5f15\u5165\u7684\u975e\u963b\u585eI\/O\u6a21\u578b，\u901a\u8fc7\u9009\u62e9\u5668\u548c\u901a\u9053\u5b9e\u73b0\u9ad8\u5e76\u53d1\u5904\u7406\u3002\u6b64\u793a\u4f8b\u5c55\u793a\u5982\u4f55\u4f7f\u7528Java NIO\u5b9e\u73b0\u4e00\u4e2a\u7b80\u5355\u7684\u670d\u52a1\u5668-\u5ba2\u6237\u7aef\u901a\u4fe1，\u6d89\u53ca\u5b57\u7b26\u4e32\u7684\u54c8\u5e0c\u8ba1\u7b97\u3002\u7b80\u8981\u4ecb\u7ecd\u4e86NIO\u5728\u670d\u52a1\u5668\u7aef\u5b9e\u73b0\u7684\u5173\u952e\u6b65\u9aa4，\u5305\u62ecServerSocketChannel\u7684\u521d\u59cb\u5316\u3001\u9009\u62e9\u5668\u7684\u6ce8\u518c\u4e0e\u4f7f\u7528\u3001\u901a\u9053\u7684\u8bfb\u5199\u64cd\u4f5c\u7b49\u3002\u672c\u793a\u4f8b\u901a\u8fc7\u7f16\u7801\u548c\u89e3\u7801\u5b57\u7b26\u4e32，\u5229\u7528\u9009\u62e9\u5668\u76d1\u542c\u901a\u9053\u4e8b\u4ef6，\u6f14\u793a\u4e86NIO\u6a21\u578b\u7684\u591a\u8def\u590d\u7528\u80fd\u529b，\u5e76\u8bf4\u660e\u4e86\u54c8\u5e0c\u503c\u7684\u8ba1\u7b97\u65b9\u6cd5\u3002 ![\"JAVA](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/05\/20250516174557-682779d53f37c.jpg\")
<\/p>\n
\u5728\u5f53\u4eca\u7684\u8f6f\u4ef6\u5f00\u53d1\u9886\u57df，\u5904\u7406\u5927\u91cf\u5e76\u53d1\u7684I\/O\u64cd\u4f5c\u662f\u4e00\u4e2a\u666e\u904d\u7684\u9700\u6c42\u3002Java NIO\u7684\u51fa\u73b0，\u4e3a\u5f00\u53d1\u8005\u63d0\u4f9b\u4e86\u4e00\u4e2a\u66f4\u9ad8\u6548\u3001\u66f4\u7075\u6d3b\u7684I\/O\u5904\u7406\u673a\u5236\u3002Java NIO\u63d0\u4f9b\u4e86\u5bf9\u975e\u963b\u585eI\/O（Non-blocking IO）\u7684\u652f\u6301，\u4f7f\u5f97\u5f00\u53d1\u8005\u80fd\u591f\u5728\u4fdd\u6301\u8fde\u63a5\u7684\u540c\u65f6，\u6267\u884c\u5176\u4ed6\u4efb\u52a1，\u5927\u5e45\u63d0\u9ad8\u4e86\u5e94\u7528\u7a0b\u5e8f\u5904\u7406\u9ad8\u5e76\u53d1I\/O\u8bf7\u6c42\u7684\u80fd\u529b\u3002 <\/p>\n
Java NIO\u901a\u8fc7\u4f7f\u7528\u7f13\u51b2\u533a(Buffer)\u3001\u901a\u9053(Channel)\u548c\u9009\u62e9\u5668(Selector)\u8fd9\u4e9b\u57fa\u672c\u7ec4\u4ef6\u6765\u5b9e\u73b0\u975e\u963b\u585eI\/O\u3002\u4e0d\u540c\u4e8e\u4f20\u7edfBIO\u7684\u5355\u7ebf\u7a0b\u5904\u7406\u6a21\u5f0f，NIO\u5f15\u5165\u4e86\u9009\u62e9\u5668\u7684\u6982\u5ff5，\u5141\u8bb8\u4e00\u4e2a\u5355\u72ec\u7684\u7ebf\u7a0b\u6765\u76d1\u89c6\u591a\u4e2a\u8f93\u5165\u901a\u9053，\u9009\u62e9\u5c31\u7eea\u7684\u901a\u9053\u6765\u5904\u7406，\u4ece\u800c\u6781\u5927\u5730\u63d0\u9ad8\u4e86\u6548\u7387\u3002 <\/p>\n
\u76f8\u8f83\u4e8e\u4f20\u7edf\u7684\u963b\u585eI\/O，Java NIO\u7684\u4e3b\u8981\u4f18\u52bf\u5728\u4e8e： <\/p>\n
\u5728\u63a5\u4e0b\u6765\u7684\u7ae0\u8282\u4e2d，\u6211\u4eec\u5c06\u8be6\u7ec6\u63a2\u8ba8Java NIO\u7684\u8fd9\u4e9b\u4f18\u52bf，\u4ee5\u53ca\u5b83\u662f\u5982\u4f55\u4e0e\u4f20\u7edf\u7684 BIO \u76f8\u6bd4\u8f83，\u5e76\u5728\u5b9e\u9645\u5e94\u7528\u4e2d\u53d1\u6325\u5176\u5f3a\u5927\u6027\u80fd\u7684\u3002\u901a\u8fc7\u7406\u89e3 NIO \u7684\u57fa\u672c\u539f\u7406\u548c\u4f18\u52bf，\u8bfb\u8005\u5c06\u80fd\u591f\u638c\u63e1 Java NIO \u7684\u6838\u5fc3\u6982\u5ff5，\u4e3a\u5728\u9ad8\u5e76\u53d1\u573a\u666f\u4e0b\u7684\u5e94\u7528\u5f00\u53d1\u6253\u4e0b\u575a\u5b9e\u7684\u57fa\u7840\u3002 <\/p>\n
Java NIO\u7684\u6838\u5fc3\u7279\u5f81\u4e4b\u4e00\u662f\u975e\u963b\u585eI\/O，\u8fd9\u4f7f\u5f97\u5b83\u5728\u9762\u5bf9\u9ad8\u5e76\u53d1\u573a\u666f\u65f6\u80fd\u63d0\u4f9b\u66f4\u4f18\u7684\u6027\u80fd\u3002\u672c\u7ae0\u5c06\u6df1\u5165\u63a2\u8ba8\u975e\u963b\u585eI\/O\u7684\u5de5\u4f5c\u539f\u7406，\u5e76\u4e0e\u4f20\u7edfBIO\u8fdb\u884c\u5bf9\u6bd4，\u63ed\u793a\u5176\u4f18\u52bf\u6240\u5728\u3002 <\/p>\n
\u975e\u963b\u585eI\/O\u7684\u6838\u5fc3\u5728\u4e8e\u901a\u9053（Channel）\u548c\u9009\u62e9\u5668（Selector）\u7684\u4f7f\u7528\u3002\u4ee5\u4e0b\u662f\u5bf9\u5176\u5de5\u4f5c\u539f\u7406\u7684\u8be6\u7ec6\u89e3\u91ca\u3002 <\/p>\n
\u901a\u9053\u662f\u4e00\u79cd\u8fde\u63a5\u5230I\/O\u670d\u52a1\u7684\u7aef\u70b9，\u5b83\u80fd\u6267\u884c\u6570\u636e\u4f20\u8f93\u3002\u7f13\u51b2\u533a\u662f\u4e00\u4e2a\u7528\u4e8e\u5b58\u50a8\u6570\u636e\u7684\u5bb9\u5668，\u901a\u9053\u5728\u8bfb\u5199\u6570\u636e\u65f6，\u5b9e\u9645\u4e0a\u662f\u5728\u64cd\u4f5c\u7f13\u51b2\u533a\u3002\u5f53\u901a\u9053\u5199\u5165\u6570\u636e\u5230\u7f13\u51b2\u533a\u65f6，\u6211\u4eec\u8bf4\u8be5\u7f13\u51b2\u533a\u88ab"\u586b\u6ee1"；\u5f53\u901a\u9053\u4ece\u7f13\u51b2\u533a\u8bfb\u53d6\u6570\u636e\u65f6，\u6211\u4eec\u8bf4\u7f13\u51b2\u533a\u88ab"\u6e05\u7a7a"\u3002\u4ee5\u4e0b\u662f\u4ee3\u7801\u793a\u4f8b： <\/p>\n
\/\/ \u521b\u5efa\u4e00\u4e2a\u7f13\u51b2\u533a
\nByteBuffer buffer = ByteBuffer.allocate(1024);<\/p>\n
\/\/ \u5199\u5165\u6570\u636e\u5230\u7f13\u51b2\u533a
\nString input = "Hello, NIO!";
\nbuffer.put(input.getBytes());<\/p>\n
\/\/ \u5728\u8bfb\u53d6\u4e4b\u524d，\u9700\u8981\u7ffb\u8f6c\u7f13\u51b2\u533a\u72b6\u6001
\nbuffer.flip();<\/p>\n
\/\/ \u8bfb\u53d6\u7f13\u51b2\u533a\u4e2d\u7684\u6570\u636e
\nwhile(buffer.hasRemaining()){
\n System.out.print((char) buffer.get());
\n}<\/p>\n
\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d， ByteBuffer \u662f\u4e00\u4e2a\u5178\u578b\u7684\u7f13\u51b2\u533a\u7c7b，\u6211\u4eec\u521b\u5efa\u4e86\u4e00\u4e2a\u53ef\u4ee5\u5b58\u50a81024\u5b57\u8282\u6570\u636e\u7684 ByteBuffer \u5b9e\u4f8b，\u7136\u540e\u628a\u4e00\u4e2a\u5b57\u7b26\u4e32\u6570\u636e\u5199\u5165\u5230\u7f13\u51b2\u533a\u4e2d\u3002\u5728\u8bfb\u53d6\u6570\u636e\u4e4b\u524d，\u6211\u4eec\u4f7f\u7528 flip() \u65b9\u6cd5\u6765\u51c6\u5907\u7f13\u51b2\u533a\u8fdb\u884c\u8bfb\u53d6，\u5b83\u5c06\u4f4d\u7f6e\u91cd\u7f6e\u4e3a0\u5e76\u6e05\u9664\u8bfb\u6807\u5fd7，\u4f7f\u5f97\u7f13\u51b2\u533a\u53ef\u4ee5\u88ab\u8bfb\u53d6\u3002 <\/p>\n
\u9009\u62e9\u5668\u662fJava NIO\u4e2d\u5b9e\u73b0\u591a\u8def\u590d\u7528\u7684\u6838\u5fc3\u7ec4\u4ef6，\u5b83\u5141\u8bb8\u4e00\u4e2a\u5355\u72ec\u7684\u7ebf\u7a0b\u6765\u76d1\u89c6\u591a\u4e2a\u8f93\u5165\u901a\u9053\u3002\u9009\u62e9\u5668\u5229\u7528\u64cd\u4f5c\u7cfb\u7edf\u63d0\u4f9b\u7684\u8d44\u6e90\u7ba1\u7406\u80fd\u529b，\u4ec5\u5728\u901a\u9053\u6709I\/O\u4e8b\u4ef6\u53d1\u751f\u65f6\u624d\u901a\u77e5\u5e94\u7528\u7a0b\u5e8f，\u4ece\u800c\u907f\u514d\u4e86\u7ebf\u7a0b\u7684\u7a7a\u95f2\u7b49\u5f85，\u63d0\u9ad8\u4e86\u7cfb\u7edf\u8d44\u6e90\u7684\u5229\u7528\u7387\u548c\u7a0b\u5e8f\u7684\u6548\u7387\u3002\u4ee5\u4e0b\u662f\u5982\u4f55\u521b\u5efa\u548c\u6ce8\u518c\u9009\u62e9\u5668\u7684\u793a\u4f8b\u4ee3\u7801： <\/p>\n
\/\/ \u521b\u5efa\u9009\u62e9\u5668
\nSelector selector = Selector.open();<\/p>\n
\/\/ \u521b\u5efa\u901a\u9053\u5e76\u8bbe\u7f6e\u4e3a\u975e\u963b\u585e\u6a21\u5f0f
\nServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
\nserverSocketChannel.configureBlocking(false);<\/p>\n
\/\/ \u6ce8\u518c\u9009\u62e9\u5668\u5e76\u76d1\u542c\u8fde\u63a5\u4e8b\u4ef6
\nSelectionKey key = serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);<\/p>\n
\/\/ \u542f\u52a8\u9009\u62e9\u5668
\nselector.select();<\/p>\n
\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d，\u6211\u4eec\u9996\u5148\u521b\u5efa\u4e86\u4e00\u4e2a\u9009\u62e9\u5668\u5b9e\u4f8b，\u7136\u540e\u6253\u5f00\u4e00\u4e2a ServerSocketChannel ，\u5c06\u5176\u914d\u7f6e\u4e3a\u975e\u963b\u585e\u6a21\u5f0f，\u5e76\u5c06\u5b83\u6ce8\u518c\u5230\u9009\u62e9\u5668\u4e0a\u3002\u6ce8\u518c\u65f6，\u6211\u4eec\u5173\u6ce8 OP_ACCEPT \u4e8b\u4ef6，\u8fd9\u610f\u5473\u7740\u6211\u4eec\u5e0c\u671b\u5f53\u6709\u65b0\u7684\u8fde\u63a5\u5230\u6765\u65f6，\u9009\u62e9\u5668\u80fd\u591f\u901a\u77e5\u6211\u4eec\u3002 <\/p>\n
\u4e0e\u975e\u963b\u585eI\/O\u76f8\u5bf9\u7684\u662f\u4f20\u7edf\u7684\u963b\u585eI\/O（Blocking I\/O），\u5176\u5de5\u4f5c\u539f\u7406\u4e0e\u975e\u963b\u585eI\/O\u5927\u76f8\u5f84\u5ead\u3002 <\/p>\n
\u5728\u4f20\u7edf\u7684\u963b\u585eI\/O\u6a21\u578b\u4e2d，\u5ba2\u6237\u7aef\u7684\u6bcf\u6b21I\/O\u64cd\u4f5c\u90fd\u4f1a\u963b\u585e\u76f8\u5e94\u7684\u7ebf\u7a0b，\u76f4\u5230\u64cd\u4f5c\u5b8c\u6210\u3002\u8fd9\u610f\u5473\u7740\u5728\u7b49\u5f85I\/O\u64cd\u4f5c\u5b8c\u6210\u671f\u95f4，\u7ebf\u7a0b\u4e0d\u80fd\u505a\u4efb\u4f55\u5176\u5b83\u5de5\u4f5c\u3002\u968f\u7740\u5e76\u53d1\u91cf\u7684\u589e\u52a0，\u8fd9\u79cd\u6a21\u578b\u4f1a\u6d88\u8017\u5927\u91cf\u7ebf\u7a0b\u8d44\u6e90，\u5e76\u5bfc\u81f4\u7cfb\u7edf\u6027\u80fd\u6025\u5267\u4e0b\u964d\u3002\u4ee5\u4f20\u7edf\u7684\u670d\u52a1\u5668\u7aefSocket\u7f16\u7a0b\u4e3a\u4f8b，\u5178\u578b\u7684\u4ee3\u7801\u5982\u4e0b： <\/p>\n
ServerSocket serverSocket = new ServerSocket(port);
\nwhile(true) {
\n \/\/ \u63a5\u53d7\u5ba2\u6237\u7aef\u8fde\u63a5，\u4f1a\u963b\u585e\u7b49\u5f85
\n Socket clientSocket = serverSocket.accept();
\n \/\/ \u4e3a\u6bcf\u4e2a\u5ba2\u6237\u7aef\u5206\u914d\u4e00\u4e2a\u65b0\u7684\u7ebf\u7a0b\u8fdb\u884c\u5904\u7406
\n new Thread(new ClientHandler(clientSocket)).start();
\n}<\/p>\n
\u6b64\u4ee3\u7801\u6bb5\u5c55\u793a\u4e86\u4f20\u7edfBIO\u7684\u963b\u585e\u7279\u6027，\u5728\u7b49\u5f85 accept() \u65b9\u6cd5\u8fd4\u56de\u4e4b\u524d，\u4e3b\u7ebf\u7a0b\u5c06\u65e0\u6cd5\u505a\u4efb\u4f55\u5176\u5b83\u4e8b\u60c5\u3002 <\/p>\n
\u4e3a\u4e86\u907f\u514d\u521b\u5efa\u5927\u91cf\u7ebf\u7a0b\u5e26\u6765\u7684\u6027\u80fd\u95ee\u9898，\u4f20\u7edfBIO\u5e38\u5e38\u4e0e\u7ebf\u7a0b\u6c60\u914d\u5408\u4f7f\u7528\u3002\u7ebf\u7a0b\u6c60\u53ef\u4ee5\u91cd\u7528\u4e00\u7ec4\u6709\u9650\u7684\u7ebf\u7a0b\u6765\u5904\u7406\u591a\u4e2a\u4efb\u52a1，\u800c\u4e0d\u662f\u4e3a\u6bcf\u4e2a\u8fde\u63a5\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u7ebf\u7a0b\u3002\u7136\u800c，\u7ebf\u7a0b\u6c60\u7684\u5f15\u5165\u867d\u7136\u7f13\u89e3\u4e86\u7ebf\u7a0b\u8d44\u6e90\u7684\u6d88\u8017，\u4f46\u7ebf\u7a0b\u7684\u9891\u7e41\u4e0a\u4e0b\u6587\u5207\u6362\u4ee5\u53ca\u7ebf\u7a0b\u7ba1\u7406\u672c\u8eab\u7684\u5f00\u9500\u4f9d\u7136\u5b58\u5728，\u4e0d\u80fd\u6839\u672c\u89e3\u51b3\u95ee\u9898\u3002 <\/p>\n
\u975e\u963b\u585eI\/O\u6a21\u578b\u901a\u8fc7\u5176\u72ec\u7279\u7684\u673a\u5236，\u6709\u6548\u5730\u89e3\u51b3\u4e86\u4f20\u7edf\u963b\u585e\u6a21\u578b\u7684\u5c40\u9650\u6027，\u5e26\u6765\u4e86\u591a\u65b9\u9762\u7684\u4f18\u52bf\u3002 <\/p>\n
\u975e\u963b\u585eI\/O\u6a21\u578b\u5229\u7528\u4e86\u64cd\u4f5c\u7cfb\u7edf\u7684\u591a\u8def\u590d\u7528\u7279\u6027，\u901a\u8fc7\u8f83\u5c11\u7684\u7ebf\u7a0b\u5c31\u80fd\u5904\u7406\u5927\u91cf\u7684\u5e76\u53d1\u8fde\u63a5\u3002\u8fd9\u79cd\u6a21\u5f0f\u4e0b，\u5e94\u7528\u7a0b\u5e8f\u4ec5\u5728I\/O\u4e8b\u4ef6\u5b9e\u9645\u53d1\u751f\u65f6\u624d\u5360\u7528CPU\u65f6\u95f4，\u5927\u5927\u51cf\u5c11\u4e86\u4e0d\u5fc5\u8981\u7684CPU\u6d88\u8017，\u4ece\u800c\u63d0\u9ad8\u4e86\u7cfb\u7edf\u7684\u6574\u4f53\u6027\u80fd\u3002 <\/p>\n
\u591a\u8def\u590d\u7528\u6280\u672f\u5141\u8bb8\u591a\u4e2a\u7f51\u7edc\u8fde\u63a5\u590d\u7528\u4e00\u4e2a\u6216\u5c11\u6570\u51e0\u4e2a\u7ebf\u7a0b，\u5f53\u67d0\u4e2a\u8fde\u63a5\u6709I\/O\u4e8b\u4ef6\u53d1\u751f\u65f6，\u5e94\u7528\u7a0b\u5e8f\u624d\u4f1a\u5bf9\u8be5\u8fde\u63a5\u8fdb\u884c\u5904\u7406\u3002\u8fd9\u79cd\u6a21\u578b\u7684\u4f18\u52bf\u5728\u4e8e\u53ef\u4ee5\u975e\u5e38\u9ad8\u6548\u5730\u5904\u7406\u5927\u91cf\u7684\u5e76\u53d1\u8fde\u63a5，\u56e0\u4e3a\u5b83\u5c06\u8fde\u63a5\u72b6\u6001\u7684\u68c0\u67e5\u548c\u5b9e\u9645\u7684\u6570\u636e\u4f20\u8f93\u5206\u79bb\u5f00\u6765，\u907f\u514d\u4e86\u7ebf\u7a0b\u7684\u65e0\u6548\u7b49\u5f85\u3002 <\/p>\n
\u901a\u8fc7\u6df1\u5165\u7406\u89e3\u975e\u963b\u585eI\/O\u7684\u5de5\u4f5c\u539f\u7406，\u5e76\u5c06\u5176\u4e0e\u4f20\u7edfBIO\u8fdb\u884c\u6bd4\u8f83，\u6211\u4eec\u6e05\u6670\u5730\u770b\u5230\u4e86Java NIO\u8bbe\u8ba1\u7684\u5408\u7406\u6027\u4e0e\u5148\u8fdb\u6027\u3002NIO\u7684\u4f18\u52bf\u4e0d\u4ec5\u4ec5\u5728\u4e8e\u7406\u8bba\u4e0a\u7684\u63d0\u5347，\u66f4\u5728\u4e8e\u5b9e\u9645\u5e94\u7528\u4e2d\u5bf9\u8d44\u6e90\u7684\u8282\u7ea6\u4e0e\u6548\u7387\u7684\u63d0\u9ad8\u3002\u8fd9\u79cd\u975e\u963b\u585e\u3001\u4e8b\u4ef6\u9a71\u52a8\u7684\u6a21\u578b\u4e3a\u6784\u5efa\u9ad8\u6027\u80fd\u3001\u9ad8\u53ef\u6269\u5c55\u6027\u7684\u7f51\u7edc\u5e94\u7528\u7a0b\u5e8f\u63d0\u4f9b\u4e86\u4e00\u4e2a\u4f18\u79c0\u7684\u89e3\u51b3\u65b9\u6848\u3002 <\/p>\n
\u63a5\u4e0b\u6765，\u6211\u4eec\u5c06\u8fdb\u4e00\u6b65\u63a2\u8ba8Java NIO\u4e2d\u7684\u5173\u952e\u7ec4\u4ef6\u2014\u2014\u901a\u9053\u548c\u9009\u62e9\u5668\u2014\u2014\u5b83\u4eec\u5982\u4f55\u5728\u5b9e\u8df5\u4e2d\u53d1\u6325\u4f5c\u7528，\u5e76\u7ed9\u51fa\u5177\u4f53\u7684\u4f7f\u7528\u793a\u4f8b\u3002 <\/p>\n
\u5728Java NIO\u4e2d，\u901a\u9053（Channel）\u548c\u9009\u62e9\u5668（Selector）\u662f\u5b9e\u73b0\u975e\u963b\u585eI\/O\u64cd\u4f5c\u7684\u5173\u952e\u7ec4\u4ef6\u3002\u672c\u7ae0\u8282\u6211\u4eec\u5c06\u6df1\u5165\u63a2\u8ba8\u901a\u9053\u548c\u9009\u62e9\u5668\u7684\u57fa\u672c\u6982\u5ff5\u3001\u5de5\u4f5c\u539f\u7406\u4ee5\u53ca\u5b83\u4eec\u7684\u8054\u5408\u4f7f\u7528\u65b9\u6cd5\u3002 <\/p>\n
\u901a\u9053（Channel）\u662fNIO\u4e2d\u7528\u4e8e\u5728\u7f13\u51b2\u533a（Buffer）\u548cI\/O\u6e90\u6216I\/O\u76ee\u6807\u4e4b\u95f4\u8fdb\u884c\u6570\u636e\u4f20\u8f93\u7684\u62bd\u8c61\u3002\u5b83\u7c7b\u4f3c\u4e8e\u4f20\u7edf\u7684\u6d41（Stream），\u4f46\u901a\u9053\u65e2\u53ef\u4ee5\u8fdb\u884c\u8bfb\u64cd\u4f5c，\u4e5f\u53ef\u4ee5\u8fdb\u884c\u5199\u64cd\u4f5c\u3002 <\/p>\n
\u901a\u9053\u7684\u7279\u6027\u5305\u62ec： – \u53cc\u5411\u6027 ：\u901a\u9053\u53ef\u4ee5\u540c\u65f6\u652f\u6301\u8bfb\u5199\u64cd\u4f5c，\u800c\u4f20\u7edf\u6d41\u901a\u5e38\u662f\u5355\u5411\u7684\u3002 – \u76f4\u63a5\u4e0e\u5185\u5b58\u4ea4\u4e92 ：\u901a\u9053\u53ef\u4ee5\u901a\u8fc7\u76f4\u63a5\u5185\u5b58（Direct Buffer）\u6765\u51cf\u5c11\u6570\u636e\u590d\u5236\u7684\u6b21\u6570，\u63d0\u9ad8\u6027\u80fd\u3002 – \u975e\u963b\u585eI\/O\u64cd\u4f5c ：\u901a\u9053\u53ef\u4ee5\u914d\u7f6e\u4e3a\u975e\u963b\u585e\u6a21\u5f0f，\u4e0d\u4f1a\u5728I\/O\u64cd\u4f5c\u65f6\u4f7f\u7ebf\u7a0b\u6302\u8d77\u3002 <\/p>\n
\u5728Java NIO\u4e2d，\u901a\u9053\u4e3b\u8981\u6709\u4e24\u79cd\u7c7b\u578b： <\/p>\n
\u6587\u4ef6\u901a\u9053\u7684\u4f7f\u7528\u793a\u4f8b\u4ee3\u7801： <\/p>\n
import java.nio.ByteBuffer;
\nimport java.nio.channels.FileChannel;
\nimport java.io.RandomAccessFile;
\nimport java.nio.file.Paths;
\nimport java.nio.file.StandardOpenOption;<\/p>\n
public class FileChannelExample {
\n public static void main(String[] args) throws Exception {
\n RandomAccessFile aFile = new RandomAccessFile("example.txt", "rw");
\n FileChannel fileChannel = aFile.getChannel();
\n ByteBuffer buf = ByteBuffer.allocate(48);<\/p>\n
int bytesRead = fileChannel.read(buf); \/\/ \u8bfb\u53d6\u6570\u636e\u5230buf\u7f13\u51b2\u533a
\n while (bytesRead != -1) {
\n buf.flip(); \/\/ \u5207\u6362\u8bfb\u6a21\u5f0f
\n while(buf.hasRemaining()){
\n System.out.print((char) buf.get()); \/\/ \u6253\u5370\u8bfb\u53d6\u7684\u6570\u636e
\n }
\n buf.clear(); \/\/ \u6e05\u7a7a\u7f13\u51b2\u533a，\u4e3a\u4e0b\u4e00\u6b21\u8bfb\u53d6\u505a\u51c6\u5907
\n bytesRead = fileChannel.read(buf); \/\/ \u7ee7\u7eed\u8bfb\u53d6\u6570\u636e
\n }
\n fileChannel.close();
\n aFile.close();
\n }
\n}<\/p>\n
\u7f51\u7edc\u901a\u9053\u7684\u4f7f\u7528\u793a\u4f8b\u4ee3\u7801： <\/p>\n
import java.nio.ByteBuffer;
\nimport java.nio.channels.SocketChannel;
\nimport java.net.InetSocketAddress;<\/p>\n
public class SocketChannelExample {
\n public static void main(String[] args) throws Exception {
\n SocketChannel socketChannel = SocketChannel.open();
\n socketChannel.connect(new InetSocketAddress("localhost", 8080));
\n String msg = "Hello NIO!";
\n ByteBuffer buffer = ByteBuffer.wrap(msg.getBytes());
\n socketChannel.write(buffer); \/\/ \u53d1\u9001\u6570\u636e
\n buffer.clear(); \/\/ \u6e05\u7a7a\u7f13\u51b2\u533a
\n socketChannel.read(buffer); \/\/ \u63a5\u6536\u6570\u636e
\n socketChannel.close();
\n }
\n}<\/p>\n
\u9009\u62e9\u5668（Selector）\u662f\u4e00\u4e2a\u53ef\u4ee5\u76d1\u542c\u591a\u4e2a\u901a\u9053（Channel）I\/O\u4e8b\u4ef6\u7684\u7ec4\u4ef6\u3002\u901a\u8fc7\u4f7f\u7528\u9009\u62e9\u5668，\u4e00\u4e2a\u7ebf\u7a0b\u53ef\u4ee5\u7ba1\u7406\u591a\u4e2a\u7f51\u7edc\u8fde\u63a5\u3002 <\/p>\n
\u9009\u62e9\u5668\u7684\u5de5\u4f5c\u539f\u7406\u57fa\u4e8e\u4ee5\u4e0b\u6b65\u9aa4： 1. \u901a\u8fc7 Selector.open() \u521b\u5efa\u9009\u62e9\u5668\u5b9e\u4f8b\u3002 2. \u5c06\u7f51\u7edc\u901a\u9053\u6ce8\u518c\u5230\u9009\u62e9\u5668\u4e0a，\u5e76\u8bbe\u7f6e\u611f\u5174\u8da3\u7684I\/O\u4e8b\u4ef6\u7c7b\u578b\u3002 3. \u5728\u9700\u8981\u7684\u65f6\u5019，\u8c03\u7528\u9009\u62e9\u5668\u7684 select() \u65b9\u6cd5\u6765\u7b49\u5f85\u4e8b\u4ef6\u7684\u53d1\u751f\u3002 4. \u5982\u679c\u6709\u901a\u9053\u4e0a\u7684\u4e8b\u4ef6\u5c31\u7eea，\u5219\u8fd4\u56de\u4e8b\u4ef6\u96c6\u5408\u3002 5. \u6839\u636e\u4e8b\u4ef6\u7c7b\u578b，\u5bf9\u76f8\u5e94\u7684\u901a\u9053\u8fdb\u884c\u64cd\u4f5c\u3002 <\/p>\n
\u9009\u62e9\u5668\u7684\u521b\u5efa\u548c\u4f7f\u7528\u793a\u4f8b\u4ee3\u7801： <\/p>\n
import java.nio.channels.*;
\nimport java.net.InetSocketAddress;
\nimport java.util.Iterator;
\nimport java.util.Set;<\/p>\n
public class SelectorExample {
\n public static void main(String[] args) throws Exception {
\n Selector selector = Selector.open();
\n ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
\n serverSocketChannel.bind(new InetSocketAddress(8080));
\n serverSocketChannel.configureBlocking(false);
\n serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);<\/p>\n
while (true) {
\n if (selector.select() > 0) {
\n Set<SelectionKey> keys = selector.selectedKeys();
\n Iterator<SelectionKey> iterator = keys.iterator();
\n while (iterator.hasNext()) {
\n SelectionKey key = iterator.next();
\n if (key.isAcceptable()) {
\n \/\/ \u5904\u7406\u65b0\u7684\u8fde\u63a5
\n } else if (key.isReadable()) {
\n \/\/ \u5904\u7406\u8bfb\u4e8b\u4ef6
\n }
\n iterator.remove(); \/\/ \u6e05\u9664\u5df2\u5904\u7406\u7684\u4e8b\u4ef6
\n }
\n }
\n }
\n }
\n}<\/p>\n
\u5f53\u901a\u9053\u6ce8\u518c\u5230\u9009\u62e9\u5668\u4e0a\u65f6，\u4f1a\u4ea7\u751f\u4e00\u4e2a SelectionKey \u5b9e\u4f8b\u3002 SelectionKey \u662f\u8868\u793a\u901a\u9053\u4e0e\u9009\u62e9\u5668\u4e4b\u95f4\u5173\u8054\u7684\u552f\u4e00\u6807\u8bc6，\u5e76\u4e14\u5305\u542b\u4e00\u4e9b\u989d\u5916\u7684\u4fe1\u606f，\u5982\u611f\u5174\u8da3\u7684\u4e8b\u4ef6\u7c7b\u578b\u548c\u901a\u9053\u9644\u52a0\u7684\u6570\u636e\u5bf9\u8c61\u3002 <\/p>\n
SelectionKey \u7684\u4e3b\u8981\u65b9\u6cd5\u5305\u62ec： – interestOps(int ops) ：\u8bbe\u7f6e\u6216\u66f4\u65b0\u611f\u5174\u8da3\u7684\u64cd\u4f5c\u96c6\u5408\u3002 – readyOps() ：\u8fd4\u56de\u901a\u9053\u5df2\u5c31\u7eea\u7684\u64cd\u4f5c\u96c6\u5408\u3002 – channel() ：\u8fd4\u56de\u5173\u8054\u7684\u901a\u9053\u3002 – selector() ：\u8fd4\u56de\u5173\u8054\u7684\u9009\u62e9\u5668\u3002 – attachment() ：\u8fd4\u56de\u9644\u52a0\u5bf9\u8c61\u3002 – attach(Object ob) ：\u8bbe\u7f6e\u9644\u52a0\u5bf9\u8c61\u3002 <\/p>\n
\u8981\u5c06\u901a\u9053\u4e0e\u9009\u62e9\u5668\u5173\u8054\u8d77\u6765，\u53ef\u4ee5\u8c03\u7528\u901a\u9053\u7684 register(Selector sel, int ops, Object att) \u65b9\u6cd5\u3002\u8fd9\u91cc\u7684\u53c2\u6570\u5305\u62ec\u9009\u62e9\u5668\u5b9e\u4f8b\u3001\u611f\u5174\u8da3\u7684I\/O\u4e8b\u4ef6\u7c7b\u578b\u4ee5\u53ca\u8981\u9644\u52a0\u5230\u9009\u62e9\u952e\u4e0a\u7684\u5bf9\u8c61\u3002 <\/p>\n
\u4f8b\u5982： <\/p>\n
ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
\nSelector selector = Selector.open();
\n\/\/ \u6ce8\u518c\u611f\u5174\u8da3\u7684\u4e8b\u4ef6\u4e3aOP_ACCEPT
\nserverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);<\/p>\n
\u4f7f\u7528\u9009\u62e9\u5668，\u6211\u4eec\u53ef\u4ee5\u5728\u5355\u4e2a\u7ebf\u7a0b\u4e2d\u76d1\u542c\u591a\u4e2a\u901a\u9053\u7684I\/O\u4e8b\u4ef6，\u8fd9\u79cd\u65b9\u5f0f\u79f0\u4e3a\u591a\u8def\u590d\u7528\u3002\u5f53\u4e8b\u4ef6\u5c31\u7eea\u65f6，\u9009\u62e9\u5668\u5c06\u8fd4\u56de\u5c31\u7eea\u7684\u901a\u9053\u96c6，\u5f00\u53d1\u8005\u53ef\u4ee5\u904d\u5386\u8fd9\u4e9b\u901a\u9053，\u5e76\u6839\u636e\u901a\u9053\u7684\u5c31\u7eea\u72b6\u6001\u6267\u884c\u76f8\u5e94\u7684\u5904\u7406\u903b\u8f91\u3002 <\/p>\n
\u4e8b\u4ef6\u7c7b\u578b\u4e3b\u8981\u5305\u62ec： – OP_ACCEPT ：\u63a5\u53d7\u8fde\u63a5\u5c31\u7eea\u3002 – OP_CONNECT ：\u8fde\u63a5\u64cd\u4f5c\u5c31\u7eea\u3002 – OP_READ ：\u8bfb\u64cd\u4f5c\u5c31\u7eea\u3002 – OP_WRITE ：\u5199\u64cd\u4f5c\u5c31\u7eea\u3002 <\/p>\n
\u793a\u4f8b： <\/p>\n
Set<SelectionKey> keys = selector.selectedKeys();
\nfor (SelectionKey key : keys) {
\n if (key.isAcceptable()) {
\n \/\/ \u5904\u7406\u63a5\u53d7\u65b0\u8fde\u63a5\u7684\u903b\u8f91
\n }
\n if (key.isReadable()) {
\n \/\/ \u5904\u7406\u8bfb\u53d6\u6570\u636e\u7684\u903b\u8f91
\n }
\n}<\/p>\n
\u901a\u8fc7\u672c\u7ae0\u8282\u7684\u4ecb\u7ecd，\u6211\u4eec\u4e86\u89e3\u4e86Java NIO\u4e2d\u901a\u9053\u548c\u9009\u62e9\u5668\u7684\u5b9a\u4e49\u3001\u7279\u70b9\u53ca\u5e94\u7528\u3002\u5728\u4e0b\u4e00\u7ae0\u8282\u4e2d，\u6211\u4eec\u5c06\u6df1\u5165\u63a2\u8ba8Java NIO\u5728\u7f51\u7edc\u7f16\u7a0b\u65b9\u9762\u7684\u5e94\u7528\u548c\u5b9e\u8df5\u3002 <\/p>\n
ServerSocketChannel\u662fJava NIO\u4e2d\u7684\u4e00\u4e2a\u7f51\u7edc\u901a\u4fe1\u901a\u9053，\u5b83\u7528\u4e8e\u76d1\u542c\u6765\u81ea\u5ba2\u6237\u7aef\u7684TCP\u8fde\u63a5\u8bf7\u6c42\u3002\u4e0e\u4f20\u7edf\u7684ServerSocket\u76f8\u6bd4，ServerSocketChannel\u652f\u6301\u975e\u963b\u585e\u6a21\u5f0f，\u8fd9\u610f\u5473\u7740\u5728\u6ca1\u6709\u8fde\u63a5\u53ef\u7528\u65f6，\u8c03\u7528ServerSocketChannel\u7684accept()\u65b9\u6cd5\u4e0d\u4f1a\u963b\u585e\u7ebf\u7a0b，\u800c\u662f\u7acb\u5373\u8fd4\u56denull\u3002 <\/p>\n
ServerSocketChannel\u5728\u5185\u90e8\u4f7f\u7528\u4e86Selector\u6765\u5b9e\u73b0\u975e\u963b\u585e\u6a21\u5f0f\u4e0b\u7684\u591a\u8def\u590d\u7528\u3002\u8fd9\u610f\u5473\u7740ServerSocketChannel\u53ef\u4ee5\u4e0e\u4e00\u4e2a\u6216\u591a\u4e2aSelector\u5bf9\u8c61\u5173\u8054，\u4ee5\u5b9e\u73b0\u5bf9\u591a\u4e2aChannel\u7684\u9ad8\u6548\u76d1\u542c\u548c\u7ba1\u7406\u3002\u5f53\u76d1\u542c\u5230\u4e8b\u4ef6（\u5982\u8fde\u63a5\u8bf7\u6c42）\u65f6，ServerSocketChannel\u4f1a\u901a\u77e5\u6ce8\u518c\u5728\u5176\u4e0a\u7684Selector，\u4ece\u800c\u53ef\u4ee5\u9ad8\u6548\u5730\u5904\u7406\u591a\u4e2a\u4e8b\u4ef6\u3002 <\/p>\n
ServerSocketChannel\u7684\u521b\u5efa\u548c\u7ed1\u5b9a\u8fc7\u7a0b\u5982\u4e0b： 1. \u9996\u5148\u901a\u8fc7 ServerSocketChannel.open() \u65b9\u6cd5\u521b\u5efa\u4e00\u4e2aServerSocketChannel\u5b9e\u4f8b\u3002 2. \u7136\u540e\u914d\u7f6e\u8be5\u5b9e\u4f8b\u4e3a\u975e\u963b\u585e\u6a21\u5f0f serverSocketChannel.configureBlocking(false); \u3002 3. \u4f7f\u7528 serverSocketChannel.socket().bind(new InetSocketAddress(port)); \u65b9\u6cd5\u7ed1\u5b9a\u5230\u6307\u5b9a\u7684\u7aef\u53e3\u3002 <\/p>\n
\u8fd9\u91cc\u6709\u4e00\u4e2a\u4ee3\u7801\u793a\u4f8b，\u5c55\u793a\u4e86\u5982\u4f55\u521d\u59cb\u5316\u548c\u914d\u7f6eServerSocketChannel： <\/p>\n
\/\/ \u6253\u5f00ServerSocketChannel
\nServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
\n\/\/ \u914d\u7f6e\u4e3a\u975e\u963b\u585e\u6a21\u5f0f
\nserverSocketChannel.configureBlocking(false);
\n\/\/ \u7ed1\u5b9a\u5230\u6307\u5b9a\u7aef\u53e3
\nInetSocketAddress isa = new InetSocketAddress(port);
\nserverSocketChannel.socket().bind(isa);<\/p>\n
\u6267\u884c\u903b\u8f91\u8bf4\u660e： – open \u65b9\u6cd5\u7528\u4e8e\u6253\u5f00\u4e00\u4e2a\u65b0\u7684ServerSocketChannel\u5b9e\u4f8b\u3002 – configureBlocking(false) \u65b9\u6cd5\u786e\u4fddServerSocketChannel\u662f\u975e\u963b\u585e\u7684\u3002 – bind \u65b9\u6cd5\u5c06ServerSocketChannel\u7ed1\u5b9a\u5230\u6307\u5b9a\u7684\u7aef\u53e3\u4e0a\u3002 <\/p>\n
\u8981\u4f7f\u7528\u9009\u62e9\u5668\u76d1\u542c\u4e8b\u4ef6，\u9996\u5148\u9700\u8981\u5c06ServerSocketChannel\u6ce8\u518c\u5230Selector\u4e0a，\u5e76\u6307\u5b9a\u611f\u5174\u8da3\u7684\u64cd\u4f5c，\u6bd4\u5982\u8fde\u63a5\u5efa\u7acb（OP_ACCEPT）\u4e8b\u4ef6\u3002\u8fd9\u901a\u8fc7\u521b\u5efa\u4e00\u4e2aSelectionKey\u6765\u5b8c\u6210，\u5b83\u4ee3\u8868\u4e86ServerSocketChannel\u548cSelector\u4e4b\u95f4\u7684\u5173\u7cfb\u3002 <\/p>\n
\u4ee5\u4e0b\u662f\u5982\u4f55\u5c06ServerSocketChannel\u6ce8\u518c\u5230Selector\u7684\u4ee3\u7801\u793a\u4f8b： <\/p>\n
\/\/ \u6253\u5f00\u9009\u62e9\u5668
\nSelector selector = Selector.open();
\n\/\/ \u6ce8\u518cServerSocketChannel\u5230\u9009\u62e9\u5668，\u5173\u6ce8\u8fde\u63a5\u4e8b\u4ef6
\nserverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);<\/p>\n
\u6267\u884c\u903b\u8f91\u8bf4\u660e： – Selector.open() \u65b9\u6cd5\u7528\u4e8e\u6253\u5f00\u4e00\u4e2a\u65b0\u7684\u9009\u62e9\u5668\u3002 – register \u65b9\u6cd5\u5c06ServerSocketChannel\u6ce8\u518c\u5230\u9009\u62e9\u5668\u4e0a，\u5e76\u6307\u660e\u5173\u6ce8\u7684\u64cd\u4f5c\u7c7b\u578b\u4e3a OP_ACCEPT \u3002 <\/p>\n
\u5f53ServerSocketChannel\u76d1\u542c\u5230\u8fde\u63a5\u8bf7\u6c42\u4e8b\u4ef6\u65f6，\u901a\u8fc7SelectionKey\u7684interestOps()\u65b9\u6cd5\u53ef\u4ee5\u68c0\u67e5\u8be5\u4e8b\u4ef6\u662f\u5426\u53d1\u751f\u3002\u53d1\u751f\u540e，\u9700\u8981\u5bf9\u8fde\u63a5\u8fdb\u884c\u63a5\u53d7\u5e76\u51c6\u5907\u8bfb\u5199\u6570\u636e\u3002 <\/p>\n
\u4ee3\u7801\u5757\u5c55\u793a\u4e86\u4e00\u4e2a\u4e8b\u4ef6\u5904\u7406\u7b56\u7565\u7684\u5b9e\u73b0： <\/p>\n
while (selector.select() > 0) {
\n \/\/ \u83b7\u53d6\u6240\u6709\u4e8b\u4ef6
\n Set<SelectionKey> keys = selector.selectedKeys();
\n Iterator<SelectionKey> iterator = keys.iterator();<\/p>\n
while (iterator.hasNext()) {
\n SelectionKey key = iterator.next();
\n iterator.remove();<\/p>\n
\/\/ \u68c0\u67e5\u662f\u5426\u662f\u8fde\u63a5\u5efa\u7acb\u4e8b\u4ef6
\n if (key.isAcceptable()) {
\n SocketChannel socketChannel = serverSocketChannel.accept();
\n socketChannel.configureBlocking(false);
\n \/\/ \u4e3a\u65b0\u8fde\u63a5\u7684SocketChannel\u6ce8\u518c\u8bfb\u4e8b\u4ef6
\n socketChannel.register(selector, SelectionKey.OP_READ);
\n }
\n \/\/ \u5176\u4ed6\u4e8b\u4ef6\u5904\u7406…
\n }
\n}<\/p>\n
\u6267\u884c\u903b\u8f91\u8bf4\u660e： – select() \u65b9\u6cd5\u963b\u585e\u5f53\u524d\u7ebf\u7a0b，\u76f4\u5230\u81f3\u5c11\u6709\u4e00\u4e2a\u4e8b\u4ef6\u53d1\u751f\u3002 – selectedKeys() \u65b9\u6cd5\u83b7\u53d6\u5df2\u9009\u62e9\u952e\u96c6，\u8fd9\u4e9b\u952e\u96c6\u4ee3\u8868\u4e86\u53d1\u751f\u7684\u4e8b\u4ef6\u3002 – isAcceptable() \u65b9\u6cd5\u7528\u4e8e\u68c0\u67e5\u4e8b\u4ef6\u662f\u5426\u4e3a\u53ef\u63a5\u53d7\u7684\u8fde\u63a5\u4e8b\u4ef6\u3002 – accept() \u65b9\u6cd5\u63a5\u53d7\u4e00\u4e2a\u65b0\u7684\u8fde\u63a5，\u5e76\u8fd4\u56de\u4e00\u4e2a\u65b0\u7684SocketChannel\u5b9e\u4f8b\u3002 – \u6ce8\u518c\u65b0SocketChannel\u5230\u9009\u62e9\u5668，\u5e76\u6307\u660e\u5173\u6ce8\u8bfb\u4e8b\u4ef6\u3002 <\/p>\n
\u901a\u9053\u7684\u8bfb\u5199\u64cd\u4f5c\u662f\u901a\u8fc7SocketChannel\u8fdb\u884c\u7684，\u6bcf\u4e2aSocketChannel\u90fd\u662f\u4e00\u4e2a\u53cc\u5411\u7684\u6570\u636e\u901a\u9053，\u65e2\u53ef\u4ee5\u4ece\u901a\u9053\u8bfb\u53d6\u6570\u636e\u5230\u7f13\u51b2\u533a，\u4e5f\u53ef\u4ee5\u5c06\u7f13\u51b2\u533a\u7684\u6570\u636e\u5199\u5165\u5230\u901a\u9053\u3002 <\/p>\n
\u4ee5\u4e0b\u662f\u5982\u4f55\u901a\u8fc7SocketChannel\u8fdb\u884c\u8bfb\u5199\u7684\u4ee3\u7801\u793a\u4f8b： <\/p>\n
ByteBuffer buffer = ByteBuffer.allocate(1024);
\nSocketChannel channel = … \/\/ \u83b7\u53d6\u5230\u6709\u6548\u7684SocketChannel\u5b9e\u4f8b
\nint bytesRead = channel.read(buffer);<\/p>\n
\/\/ \u5c06buffer\u5207\u6362\u5230\u8bfb\u6a21\u5f0f
\nbuffer.flip();<\/p>\n
\/\/ \u4ecebuffer\u4e2d\u8bfb\u53d6\u6570\u636e
\nwhile(buffer.hasRemaining()) {
\n System.out.print((char) buffer.get());
\n}<\/p>\n
\/\/ \u5199\u5165\u6570\u636e\u5230\u901a\u9053
\nbuffer.clear();
\nbuffer.put("Data to send".getBytes());
\nbuffer.flip();
\nint bytesWritten = channel.write(buffer);<\/p>\n
\u6267\u884c\u903b\u8f91\u8bf4\u660e： – allocate \u65b9\u6cd5\u7528\u4e8e\u5206\u914d\u4e00\u4e2a\u65b0\u7684\u7f13\u51b2\u533a\u3002 – read \u65b9\u6cd5\u4ece\u901a\u9053\u8bfb\u53d6\u6570\u636e\u5230\u7f13\u51b2\u533a，\u8fd4\u56de\u8bfb\u53d6\u7684\u5b57\u8282\u6570\u3002 – flip \u65b9\u6cd5\u7528\u4e8e\u51c6\u5907\u4ece\u7f13\u51b2\u533a\u8bfb\u53d6\u6570\u636e，\u5c06limit\u8bbe\u7f6e\u4e3aposition，\u5e76\u5c06position\u7f6e\u4e3a0\u3002 – hasRemaining \u65b9\u6cd5\u68c0\u67e5\u7f13\u51b2\u533a\u662f\u5426\u8fd8\u6709\u5269\u4f59\u6570\u636e\u3002 – get \u65b9\u6cd5\u4ece\u7f13\u51b2\u533a\u4e2d\u8bfb\u53d6\u6570\u636e\u3002 – clear \u65b9\u6cd5\u7528\u4e8e\u6e05\u9664\u7f13\u51b2\u533a，\u51c6\u5907\u518d\u6b21\u5199\u5165\u6570\u636e\u3002 – put \u65b9\u6cd5\u7528\u4e8e\u5c06\u6570\u636e\u5199\u5165\u7f13\u51b2\u533a\u3002 – write \u65b9\u6cd5\u5c06\u7f13\u51b2\u533a\u7684\u6570\u636e\u5199\u5165\u5230\u901a\u9053，\u8fd4\u56de\u5199\u5165\u7684\u5b57\u8282\u6570\u3002 <\/p>\n
\u6b63\u786e\u5730\u4f7f\u7528\u7f13\u51b2\u533a\u662f\u63d0\u9ad8\u6570\u636e\u5904\u7406\u6548\u7387\u7684\u5173\u952e\u3002\u4e0b\u9762\u662f\u4e00\u4e9b\u6570\u636e\u5904\u7406\u6280\u5de7： <\/p>\n
\u8fd9\u91cc\u662f\u4e00\u4e2a\u5c55\u793a\u4e86\u5982\u4f55\u4f7f\u7528 compact() \u65b9\u6cd5\u7684\u4ee3\u7801\u793a\u4f8b： <\/p>\n
int bytesRead = channel.read(buffer);
\nbuffer.flip();<\/p>\n
\/\/ \u5904\u7406\u6570\u636e…<\/p>\n
\/\/ \u5199\u5165\u5b8c\u6210\u540e，\u51c6\u5907\u66f4\u591a\u6570\u636e
\nbuffer.compact();<\/p>\n
\u6267\u884c\u903b\u8f91\u8bf4\u660e： – \u5f53\u7f13\u51b2\u533a\u88ab\u8bfb\u53d6\u540e，\u8c03\u7528 compact() \u65b9\u6cd5\u5c06\u672a\u8bfb\u53d6\u7684\u6570\u636e\u79fb\u81f3\u7f13\u51b2\u533a\u7684\u5f00\u5934，\u5e76\u51c6\u5907\u63a5\u6536\u66f4\u591a\u6570\u636e\u3002 <\/p>\n
\u901a\u8fc7\u4e0a\u8ff0\u5b9e\u4f8b\u548c\u4ee3\u7801\u7684\u4f7f\u7528，\u8bfb\u8005\u5e94\u8be5\u80fd\u591f\u5bf9Java NIO\u7f51\u7edc\u7f16\u7a0b\u6709\u4e00\u4e2a\u6bd4\u8f83\u6df1\u5165\u7684\u7406\u89e3\u548c\u638c\u63e1\u3002\u63a5\u4e0b\u6765，\u6211\u4eec\u5c06\u5728\u7b2c\u4e94\u7ae0\u4e2d\u6df1\u5165\u63a2\u8ba8NIO\u6570\u636e\u5904\u7406\u4e0e\u4f18\u5316\u3002 <\/p>\n
\u5728\u5904\u7406\u5927\u89c4\u6a21\u6570\u636e\u65f6，\u6570\u636e\u7684\u5b58\u53d6\u548c\u4f20\u8f93\u6548\u7387\u76f4\u63a5\u5173\u7cfb\u5230\u5e94\u7528\u7a0b\u5e8f\u7684\u6027\u80fd\u3002Java NIO\u901a\u8fc7Buffer\u63d0\u4f9b\u4e86\u9ad8\u6548\u7684\u6570\u636e\u5904\u7406\u673a\u5236，\u800c\u5176\u975e\u963b\u585e\u7279\u6027\u4e5f\u4e3a\u6570\u636e\u7684\u5373\u65f6\u6821\u9a8c\u548c\u5904\u7406\u63d0\u4f9b\u4e86\u53ef\u80fd\u3002\u672c\u7ae0\u5c06\u6df1\u5165\u4e86\u89e3Buffer\u7684\u4f7f\u7528\u65b9\u6cd5\u548c\u5b57\u7b26\u4e32\u7f16\u7801\u89e3\u7801\u673a\u5236，\u540c\u65f6\u63a2\u8ba8\u5982\u4f55\u5229\u7528NIO\u8fdb\u884c\u6570\u636e\u6821\u9a8c\u548c\u4f18\u5316\u3002 <\/p>\n
Buffer\u662fNIO\u6570\u636e\u5904\u7406\u7684\u6838\u5fc3\u7ec4\u4ef6\u4e4b\u4e00，\u5b83\u662f\u4e00\u4e2a\u5bf9\u8c61，\u4ee3\u8868\u4e86\u6570\u636e\u7684\u4e34\u65f6\u5b58\u50a8\u3002\u6240\u6709\u7684NIO\u6570\u636e\u4f20\u8f93\u90fd\u662f\u901a\u8fc7Buffer\u5b8c\u6210\u7684，\u65e0\u8bba\u662f\u4ece\u7f51\u7edc\u8bfb\u53d6\u6570\u636e\u5230\u5185\u5b58，\u8fd8\u662f\u4ece\u5185\u5b58\u4f20\u8f93\u5230\u7f51\u7edc\u3002 <\/p>\n
Buffer\u53ef\u4ee5\u770b\u4f5c\u662f\u4e00\u4e2a\u6570\u7ec4，\u5b83\u53ef\u4ee5\u88ab\u586b\u5145\u6570\u636e\u3001\u8bfb\u53d6\u6570\u636e，\u5e76\u4e14\u53ef\u4ee5\u67e5\u8be2\u6570\u636e\u7684\u72b6\u6001\u3002Buffer\u7684\u4e3b\u8981\u5c5e\u6027\u5305\u62ec\u5bb9\u91cf（capacity）\u3001\u4f4d\u7f6e（position）\u3001\u9650\u5236（limit）\u548c\u6807\u8bb0（mark）\u3002 <\/p>\n
Buffer\u6709\u591a\u79cd\u7c7b\u578b，\u5305\u62ecByteBuffer\u3001CharBuffer\u3001ShortBuffer\u3001IntBuffer\u3001LongBuffer\u3001FloatBuffer\u3001DoubleBuffer\u7b49\u3002\u6bcf\u79cd\u7c7b\u578b\u90fd\u5bf9\u5e94Java\u57fa\u672c\u6570\u636e\u7c7b\u578b\u7684\u5b58\u50a8\u3002 <\/p>\n
Buffer\u64cd\u4f5c\u901a\u5e38\u5305\u542b\u4ee5\u4e0b\u6b65\u9aa4： <\/p>\n
\u6027\u80fd\u4f18\u5316\u65b9\u9762，Buffer\u63d0\u4f9b\u4e86 DirectBuffer ，\u8fd9\u7c7bBuffer\u7684\u6570\u636e\u76f4\u63a5\u5728\u7cfb\u7edf\u5185\u5b58\u4e2d\u5206\u914d，\u800c\u975eJVM\u7ba1\u7406\u7684\u5806\u5185\u5b58\u3002\u5b83\u53ef\u4ee5\u51cf\u5c11\u4e00\u6b21\u6570\u636e\u590d\u5236，\u4ece\u800c\u63d0\u9ad8\u6027\u80fd，\u7279\u522b\u662f\u5728\u5904\u7406\u5927\u91cf\u6570\u636e\u65f6\u3002 <\/p>\n
Java NIO\u4e0d\u4ec5\u5728\u5b57\u8282\u7ea7\u522b\u63d0\u4f9b\u4e86\u9ad8\u6548\u7684\u6570\u636e\u5904\u7406，\u8fd8\u63d0\u4f9b\u4e86\u5b57\u7b26\u96c6（Charset）\u7684\u62bd\u8c61，\u4ee5\u652f\u6301\u5b57\u7b26\u4e32\u7684\u7f16\u7801\u548c\u89e3\u7801\u3002 <\/p>\n
\u7f16\u7801（Encoding）\u662f\u5c06\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u5b57\u8282\u5e8f\u5217\u7684\u8fc7\u7a0b，\u89e3\u7801（Decoding）\u5219\u662f\u5c06\u5b57\u8282\u5e8f\u5217\u8f6c\u6362\u56de\u5b57\u7b26\u4e32\u7684\u8fc7\u7a0b\u3002\u5728Java NIO\u4e2d，Charset\u7c7b\u548c\u76f8\u5173\u7684CharsetEncoder\u548cCharsetDecoder\u7c7b\u63d0\u4f9b\u4e86\u8fd9\u4e9b\u529f\u80fd\u3002 <\/p>\n
\u4f7f\u7528Charset\u65f6，\u53ef\u4ee5\u901a\u8fc7Charset\u7684 forName() \u65b9\u6cd5\u83b7\u53d6\u4e00\u4e2aCharset\u5b9e\u4f8b\u3002\u7136\u540e，\u5229\u7528Charset\u5b9e\u4f8b\u7684 newEncoder() \u548c newDecoder() \u65b9\u6cd5\u6765\u83b7\u53d6\u76f8\u5e94\u7684\u7f16\u7801\u5668\u548c\u89e3\u7801\u5668\u3002 <\/p>\n
\u4ee5\u4e0b\u662f\u4f7f\u7528NIO\u8fdb\u884c\u5b57\u7b26\u4e32\u7f16\u7801\u89e3\u7801\u7684\u57fa\u672c\u6b65\u9aa4： <\/p>\n
\u4ee3\u7801\u793a\u4f8b： <\/p>\n
Charset charset = Charset.forName("UTF-8");
\nCharsetEncoder encoder = charset.newEncoder();
\nCharsetDecoder decoder = charset.newDecoder();<\/p>\n
CharBuffer charBuffer = CharBuffer.allocate(1024);
\ncharBuffer.put("Hello, World!");
\ncharBuffer.flip();<\/p>\n
ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
\nencoder.encode(charBuffer, byteBuffer, true);
\nbyteBuffer.flip();<\/p>\n
CharBuffer decodedBuffer = charset.decode(byteBuffer);
\nSystem.out.println(decodedBuffer.toString());<\/p>\n
\u6570\u636e\u5728\u4f20\u8f93\u8fc7\u7a0b\u4e2d\u53ef\u80fd\u4f1a\u635f\u574f，\u56e0\u6b64\u9700\u8981\u4e00\u79cd\u65b9\u5f0f\u6765\u9a8c\u8bc1\u6570\u636e\u7684\u5b8c\u6574\u6027\u3002\u54c8\u5e0c\u51fd\u6570\u53ef\u4ee5\u7528\u6765\u8ba1\u7b97\u6570\u636e\u7684\u54c8\u5e0c\u503c，\u901a\u8fc7\u6bd4\u5bf9\u54c8\u5e0c\u503c\u6765\u9a8c\u8bc1\u6570\u636e\u662f\u5426\u88ab\u7be1\u6539\u3002 <\/p>\n
\u54c8\u5e0c\u7b97\u6cd5\u662f\u4e00\u79cd\u5c06\u8f93\u5165\u6570\u636e\u8f6c\u6362\u4e3a\u56fa\u5b9a\u957f\u5ea6\u8f93\u51fa（\u54c8\u5e0c\u503c）\u7684\u7b97\u6cd5\u3002\u4e00\u4e2a\u597d\u7684\u54c8\u5e0c\u7b97\u6cd5\u5e94\u5f53\u6ee1\u8db3\u4ee5\u4e0b\u6761\u4ef6： <\/p>\n
\u5e94\u7528\u573a\u666f\u5305\u62ec\u6570\u636e\u5b8c\u6574\u6027\u6821\u9a8c\u3001\u6570\u636e\u7d22\u5f15\u548c\u6620\u5c04\u3001\u5bc6\u7801\u5b58\u50a8\u7b49\u3002 <\/p>\n
\u5728Java NIO\u4e2d，\u53ef\u4ee5\u4f7f\u7528MessageDigest\u7c7b\u6765\u8ba1\u7b97\u6570\u636e\u7684\u54c8\u5e0c\u503c\u3002\u4f7f\u7528NIO\u8bfb\u53d6\u6570\u636e\u5230Buffer\u540e，\u53ef\u4ee5\u5229\u7528\u8fd9\u4e9bBuffer\u7684\u6570\u636e\u76f4\u63a5\u8ba1\u7b97\u54c8\u5e0c\u503c，\u65e0\u9700\u5148\u5c06\u6570\u636e\u5199\u5165\u6570\u7ec4\u6216\u5b57\u7b26\u4e32\u3002 <\/p>\n
\u4ee3\u7801\u793a\u4f8b： <\/p>\n
MessageDigest digest = MessageDigest.getInstance("SHA-256");<\/p>\n
\/\/ \u5047\u8bbe\u6211\u4eec\u5df2\u7ecf\u8bfb\u53d6\u6570\u636e\u5230ByteBuffer
\nByteBuffer byteBuffer = ByteBuffer.allocate(1024);
\n\/\/ …（\u8bfb\u53d6\u6570\u636e\u5230ByteBuffer\u7684\u903b\u8f91）<\/p>\n
\/\/ \u8ba1\u7b97\u54c8\u5e0c\u503c
\nwhile (byteBuffer.hasRemaining()) {
\n digest.update(byteBuffer.get());
\n}<\/p>\n
byte[] hashBytes = digest.digest();
\n\/\/ \u8f93\u51fa\u6216\u5b58\u50a8\u54c8\u5e0c\u503c
\nSystem.out.println(Hex.encodeToString(hashBytes));<\/p>\n
\u901a\u8fc7\u4e0a\u8ff0\u7ae0\u8282，\u6211\u4eec\u53ef\u4ee5\u770b\u5230Java NIO\u5728\u6570\u636e\u5904\u7406\u548c\u4f18\u5316\u65b9\u9762\u7684\u5f3a\u5927\u529f\u80fd\u3002\u5728\u5904\u7406\u5927\u91cf\u6570\u636e\u7684\u573a\u666f\u4e0b，\u5408\u7406\u5229\u7528Buffer\u3001\u5b57\u7b26\u96c6\u548c\u54c8\u5e0c\u6821\u9a8c，\u53ef\u4ee5\u4f7f\u5e94\u7528\u7a0b\u5e8f\u66f4\u52a0\u9ad8\u6548\u548c\u7a33\u5b9a\u3002\u4e0b\u4e00\u7ae0\u5c06\u63a2\u8ba8\u5982\u4f55\u5728\u5b9e\u9645\u9879\u76ee\u4e2d\u7efc\u5408\u8fd0\u7528\u8fd9\u4e9b\u77e5\u8bc6，\u5b9e\u73b0\u66f4\u590d\u6742\u7684\u5e94\u7528\u9700\u6c42\u3002 <\/p>\n
\u672c\u6587\u8fd8\u6709\u914d\u5957\u7684\u7cbe\u54c1\u8d44\u6e90，\u70b9\u51fb\u83b7\u53d6 <\/p>\n
\u7b80\u4ecb：Java NIO\u662f\u81ea1.4\u7248\u672c\u5f15\u5165\u7684\u975e\u963b\u585eI\/O\u6a21\u578b，\u901a\u8fc7\u9009\u62e9\u5668\u548c\u901a\u9053\u5b9e\u73b0\u9ad8\u5e76\u53d1\u5904\u7406\u3002\u6b64\u793a\u4f8b\u5c55\u793a\u5982\u4f55\u4f7f\u7528Java NIO\u5b9e\u73b0\u4e00\u4e2a\u7b80\u5355\u7684\u670d\u52a1\u5668-\u5ba2\u6237\u7aef\u901a\u4fe1，\u6d89\u53ca\u5b57\u7b26\u4e32\u7684\u54c8\u5e0c\u8ba1\u7b97\u3002\u7b80\u8981\u4ecb\u7ecd\u4e86NIO\u5728\u670d\u52a1\u5668\u7aef\u5b9e\u73b0\u7684\u5173\u952e\u6b65\u9aa4，\u5305\u62ecServerSocketChannel\u7684\u521d\u59cb\u5316\u3001\u9009\u62e9\u5668\u7684\u6ce8\u518c\u4e0e\u4f7f\u7528\u3001\u901a\u9053\u7684\u8bfb\u5199\u64cd\u4f5c\u7b49\u3002\u672c\u793a\u4f8b\u901a\u8fc7\u7f16\u7801\u548c\u89e3\u7801\u5b57\u7b26\u4e32，\u5229\u7528\u9009\u62e9\u5668\u76d1\u542c\u901a\u9053\u4e8b\u4ef6，\u6f14\u793a\u4e86NIO\u6a21\u578b\u7684\u591a\u8def\u590d\u7528\u80fd\u529b，\u5e76\u8bf4\u660e\u4e86\u54c8\u5e0c\u503c\u7684\u8ba1\u7b97\u65b9\u6cd5\u3002 <\/p>\n
\u672c\u6587\u8fd8\u6709\u914d\u5957\u7684\u7cbe\u54c1\u8d44\u6e90，\u70b9\u51fb\u83b7\u53d6 <\/p><\/p>\n","protected":false},"excerpt":{"rendered":"
\u6587\u7ae0\u6d4f\u89c8\u9605\u8bfb695\u6b21\uff0c\u70b9\u8d5e13\u6b21\uff0c\u6536\u85cf10\u6b21\u3002\u901a\u8fc7\u6df1\u5165\u7406\u89e3\u975e\u963b\u585eI\/O\u7684\u5de5\u4f5c\u539f\u7406\uff0c\u5e76\u5c06\u5176\u4e0e\u4f20\u7edfBIO\u8fdb\u884c\u6bd4\u8f83\uff0c\u6211\u4eec\u6e05\u6670\u5730\u770b\u5230\u4e86Java NIO\u8bbe\u8ba1\u7684\u5408\u7406\u6027\u4e0e\u5148\u8fdb\u6027\u3002NIO\u7684\u4f18\u52bf\u4e0d\u4ec5\u4ec5\u5728\u4e8e\u7406\u8bba\u4e0a\u7684\u63d0\u5347\uff0c\u66f4\u5728\u4e8e\u5b9e\u9645\u5e94\u7528\u4e2d\u5bf9\u8d44\u6e90\u7684\u8282\u7ea6\u4e0e\u6548\u7387\u7684\u63d0\u9ad8\u3002\u8fd9\u79cd\u975e\u963b\u585e\u3001\u4e8b\u4ef6\u9a71\u52a8\u7684\u6a21\u578b\u4e3a\u6784\u5efa\u9ad8\u6027\u80fd\u3001\u9ad8\u53ef\u6269\u5c55\u6027\u7684\u7f51\u7edc\u5e94\u7528\u7a0b\u5e8f\u63d0\u4f9b\u4e86\u4e00\u4e2a\u4f18\u79c0\u7684\u89e3\u51b3\u65b9\u6848\u3002\u63a5\u4e0b\u6765\uff0c\u6211\u4eec\u5c06\u8fdb\u4e00\u6b65\u63a2\u8ba8Java NIO\u4e2d\u7684\u5173\u952e\u7ec4\u4ef6\u2014\u2014\u901a\u9053\u548c\u9009\u62e9\u5668\u2014\u2014\u5b83\u4eec\u5982\u4f55\u5728\u5b9e\u8df5\u4e2d\u53d1\u6325\u4f5c\u7528\uff0c\u5e76\u7ed9\u51fa\u5177\u4f53\u7684\u4f7f\u7528\u793a\u4f8b\u3002<\/p>\n","protected":false},"author":2,"featured_media":37693,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"topic":[],"class_list":["post-37695","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-server"],"yoast_head":"\n