\u4f60\u6709\u6ca1\u6709\u9047\u5230\u8fc7\u8fd9\u6837\u7684\u9700\u6c42？<\/p>\n
👉 \u60f3\u7ed9\u67d0\u4e2a\u65b9\u6cd5\u52a0\u4e2a\u8017\u65f6\u7edf\u8ba1，\u4f46\u4e0d\u60f3\u6539\u539f\u6709\u4ee3\u7801？
\n👉 \u60f3\u5728\u6bcf\u4e2a\u4e1a\u52a1\u65b9\u6cd5\u6267\u884c\u524d\u540e\u6253\u5370\u65e5\u5fd7，\u96be\u9053\u8981\u6bcf\u4e2a\u65b9\u6cd5\u90fd\u624b\u52a8\u52a0 log.info()？
\n👉 \u9762\u8bd5\u5b98\u95ee：\u201cSpring \u7684 AOP \u662f\u600e\u4e48\u5b9e\u73b0\u7684？\u201d \u4f60\u5fc3\u91cc\u4e00\u7d27，\u53ea\u618b\u51fa\u4e00\u53e5：\u201c\u55ef\u2026\u2026\u7528\u4e86\u4ee3\u7406？\u201d<\/p>\n
\n\u5e26\u4f60\u5f7b\u5e95\u641e\u61c2 Java \u52a8\u6001\u4ee3\u7406（Dynamic Proxy）！<\/p>\n
\u5b83\u5c31\u50cf\u7ed9\u5bf9\u8c61\u88c5\u4e86\u4e2a\u201c\u5f71\u5206\u8eab\u201d，
\n\u4f60\u8c03\u7528\u7684\u662f\u5b83，\u5b9e\u9645\u6267\u884c\u7684\u5374\u662f\u53e6\u4e00\u4e2a\u201c\u5e55\u540e\u9ed1\u624b\u201d\u2014\u2014
\n\u800c\u4e14\u8fd9\u4e00\u5207，\u5728\u8fd0\u884c\u65f6\u81ea\u52a8\u751f\u6210，\u4e0d\u7528\u4f60\u624b\u5199\u4e00\u884c\u4ee3\u7406\u7c7b！<\/p>\n
\u60f3\u8c61\u4e00\u4e0b，\u660e\u661f（\u771f\u5b9e\u5bf9\u8c61）\u5f88\u5fd9，\u4e0d\u80fd\u4eb2\u81ea\u5904\u7406\u6240\u6709\u4e8b\u3002
\n\u4e8e\u662f\u4ed6\u627e\u4e86\u4e2a\u7ecf\u7eaa\u4eba（\u4ee3\u7406），\u5bf9\u5916\u8bf4：\u201c\u6709\u4e8b\u627e\u6211！\u201d<\/p>\n
\u7c89\u4e1d（\u8c03\u7528\u8005）\u4ee5\u4e3a\u5728\u8ddf\u660e\u661f\u6253\u4ea4\u9053，
\n\u5176\u5b9e\u662f\u7ecf\u7eaa\u4eba\u5728\u63a5\u7535\u8bdd\u3001\u8c08\u5408\u540c\u3001\u5b89\u6392\u884c\u7a0b\u2026\u2026
\n\u5fc5\u8981\u65f6，\u7ecf\u7eaa\u4eba\u624d\u4f1a\u53bb\u201c\u901a\u77e5\u201d\u660e\u661f\u672c\u4eba\u3002<\/p>\n
\u5728 Java \u4e16\u754c\u91cc：<\/p>\n
\u2705 \u52a8\u6001\u4ee3\u7406 = \u5728\u7a0b\u5e8f\u8fd0\u884c\u65f6，\u81ea\u52a8\u751f\u6210\u4e00\u4e2a\u201c\u4ee3\u7406\u7c7b\u201d，\u4ee3\u66ff\u771f\u5b9e\u5bf9\u8c61\u5904\u7406\u8bf7\u6c42<\/p>\n
\u8981\u6c42：\u88ab\u4ee3\u7406\u7684\u7c7b\u5fc5\u987b\u5b9e\u73b0\u81f3\u5c11\u4e00\u4e2a\u63a5\u53e3\u3002<\/p>\n
\/\/ 1. \u5b9a\u4e49\u63a5\u53e3
\npublic interface UserService {
\n void saveUser(String name);
\n String getUser(int id);
\n}<\/p>\n
\/\/ 2. \u771f\u5b9e\u5b9e\u73b0\u7c7b（\u660e\u661f\u672c\u4eba）
\npublic class UserServiceImpl implements UserService {
\n @Override
\n public void saveUser(String name) {
\n System.out.println("\u6b63\u5728\u4fdd\u5b58\u7528\u6237：" + name);
\n \/\/ \u6a21\u62df\u8017\u65f6
\n try { Thread.sleep(100); } catch (InterruptedException e) {}
\n }<\/p>\n
@Override
\n public String getUser(int id) {
\n System.out.println("\u6b63\u5728\u67e5\u8be2\u7528\u6237：" + id);
\n return "\u7528\u6237" + id;
\n }
\n}<\/p>\n
\/\/ 3. \u7ecf\u7eaa\u4eba（InvocationHandler）\u2014\u2014 \u6838\u5fc3！\u62e6\u622a\u6240\u6709\u65b9\u6cd5\u8c03\u7528
\npublic class LoggingInvocationHandler implements InvocationHandler {
\n private Object target; \/\/ \u771f\u5b9e\u5bf9\u8c61<\/p>\n
public LoggingInvocationHandler(Object target) {
\n this.target = target;
\n }<\/p>\n
@Override
\n public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
\n \/\/ \u3010\u524d\u7f6e\u589e\u5f3a\u3011\u65b9\u6cd5\u6267\u884c\u524d
\n String methodName = method.getName();
\n System.out.println("\u3010\u4ee3\u7406\u62e6\u622a\u3011\u5373\u5c06\u6267\u884c\u65b9\u6cd5：" + methodName + "，\u53c2\u6570：" + Arrays.toString(args));<\/p>\n
long start = System.currentTimeMillis();<\/p>\n
\/\/ \u3010\u6838\u5fc3\u3011\u8c03\u7528\u771f\u5b9e\u5bf9\u8c61\u7684\u65b9\u6cd5
\n Object result = method.invoke(target, args);<\/p>\n
\/\/ \u3010\u540e\u7f6e\u589e\u5f3a\u3011\u65b9\u6cd5\u6267\u884c\u540e
\n long cost = System.currentTimeMillis() – start;
\n System.out.println("\u3010\u4ee3\u7406\u62e6\u622a\u3011\u65b9\u6cd5 " + methodName + " \u6267\u884c\u5b8c\u6210，\u8017\u65f6：" + cost + "ms，\u8fd4\u56de\u503c：" + result);<\/p>\n
return result;
\n }
\n}<\/p>\n
\/\/ 4. \u5ba2\u6237\u7aef\u4f7f\u7528（\u7c89\u4e1d\u627e\u660e\u661f）
\npublic class Client {
\n public static void main(String[] args) {
\n \/\/ \u771f\u5b9e\u5bf9\u8c61
\n UserService realService = new UserServiceImpl();<\/p>\n
\/\/ \u521b\u5efa\u4ee3\u7406\u5bf9\u8c61（\u7ecf\u7eaa\u4eba\u4e0a\u5c97！）
\n UserService proxyService = (UserService) Proxy.newProxyInstance(
\n realService.getClass().getClassLoader(), \/\/ \u7c7b\u52a0\u8f7d\u5668
\n realService.getClass().getInterfaces(), \/\/ \u4ee3\u7406\u54ea\u4e9b\u63a5\u53e3
\n new LoggingInvocationHandler(realService) \/\/ \u4ee3\u7406\u903b\u8f91
\n );<\/p>\n
\/\/ \u8c03\u7528\u8005\u4ee5\u4e3a\u5728\u8c03\u771f\u5b9e\u5bf9\u8c61，\u5176\u5b9e\u662f\u4ee3\u7406\u5728\u5904\u7406
\n proxyService.saveUser("\u5f20\u4e09");
\n proxyService.getUser(1001);
\n }
\n}<\/p>\n
\u3010\u4ee3\u7406\u62e6\u622a\u3011\u5373\u5c06\u6267\u884c\u65b9\u6cd5：saveUser，\u53c2\u6570：[\u5f20\u4e09]
\n\u6b63\u5728\u4fdd\u5b58\u7528\u6237：\u5f20\u4e09
\n\u3010\u4ee3\u7406\u62e6\u622a\u3011\u65b9\u6cd5 saveUser \u6267\u884c\u5b8c\u6210，\u8017\u65f6：105ms，\u8fd4\u56de\u503c：null<\/p>\n
\u3010\u4ee3\u7406\u62e6\u622a\u3011\u5373\u5c06\u6267\u884c\u65b9\u6cd5：getUser，\u53c2\u6570：[1001]
\n\u6b63\u5728\u67e5\u8be2\u7528\u6237：1001
\n\u3010\u4ee3\u7406\u62e6\u622a\u3011\u65b9\u6cd5 getUser \u6267\u884c\u5b8c\u6210，\u8017\u65f6：2ms，\u8fd4\u56de\u503c：\u7528\u62371001<\/p>\n
💡 \u770b！\u6211\u4eec\u6ca1\u6539\u4e00\u884c UserServiceImpl \u7684\u4ee3\u7801，\u5c31\u5b9e\u73b0\u4e86\u65e5\u5fd7\u548c\u6027\u80fd\u76d1\u63a7！<\/p>\n
\u95ee\u9898：\u5982\u679c\u7c7b\u6ca1\u5b9e\u73b0\u63a5\u53e3，JDK \u4ee3\u7406\u5c31\u6b47\u83dc\u4e86\u3002<\/p>\n
\u89e3\u51b3\u65b9\u6848：CGLIB（Code Generation Library）
\n\u5b83\u901a\u8fc7\u7ee7\u627f\u771f\u5b9e\u7c7b，\u751f\u6210\u5b50\u7c7b\u4f5c\u4e3a\u4ee3\u7406\u3002<\/p>\n
\/\/ \u4e00\u4e2a\u6ca1\u6709\u63a5\u53e3\u7684\u7c7b
\npublic class OrderService {
\n public void createOrder(String orderId) {
\n System.out.println("\u521b\u5efa\u8ba2\u5355：" + orderId);
\n }
\n}<\/p>\n
Spring AOP \u4f1a\u751f\u6210\u4e00\u4e2a\u4ee3\u7406\u7c7b，\u50cf\u8fd9\u6837：<\/p>\n
\/\/ \u4f2a\u4ee3\u7801：CGLIB \u751f\u6210\u7684\u4ee3\u7406\u7c7b
\npublic class OrderService$$EnhancerByCGLIB extends OrderService {
\n private MethodInterceptor interceptor;<\/p>\n
@Override
\n public void createOrder(String orderId) {
\n \/\/ \u8c03\u7528\u62e6\u622a\u5668（\u7c7b\u4f3c InvocationHandler）
\n interceptor.intercept(this, \u65b9\u6cd5\u5bf9\u8c61, \u53c2\u6570, \u539f\u65b9\u6cd5\u5f15\u7528);
\n }
\n}<\/p>\n
public class UserServiceProxy implements UserService {
\n private UserService target;<\/p>\n
public UserServiceProxy(UserService target) {
\n this.target = target;
\n }<\/p>\n
@Override
\n public void saveUser(String name) {
\n System.out.println("\u524d\u7f6e\u65e5\u5fd7");
\n target.saveUser(name);
\n System.out.println("\u540e\u7f6e\u65e5\u5fd7");
\n }<\/p>\n
\/\/ getUser \u4e5f\u8981\u5199\u4e00\u904d\u2026\u2026\u91cd\u590d\u4ee3\u7801！
\n}<\/p>\n
\u2705 \u52a8\u6001\u4ee3\u7406 = \u9ad8\u5ea6\u590d\u7528，\u65e0\u9700\u63d0\u524d\u5199\u4ee3\u7406\u7c7b，\u8fd0\u884c\u65f6\u81ea\u52a8\u751f\u6210<\/p>\n
| \u5b9e\u73b0\u673a\u5236<\/td>\n | \u57fa\u4e8e\u63a5\u53e3，\u751f\u6210\u5b9e\u73b0\u7c7b<\/td>\n | \u57fa\u4e8e\u7ee7\u627f，\u751f\u6210\u5b50\u7c7b<\/td>\n<\/tr>\n | ||||||||||||
| \u662f\u5426\u9700\u8981\u63a5\u53e3<\/td>\n | \u5fc5\u987b\u6709<\/td>\n | \u4e0d\u9700\u8981<\/td>\n<\/tr>\n | ||||||||||||
| \u4ee3\u7406 final \u7c7b<\/td>\n | \u4e0d\u884c<\/td>\n | \u4e0d\u884c<\/td>\n<\/tr>\n | ||||||||||||
| \u6027\u80fd<\/td>\n | JDK 1.8+ \u5df2\u4f18\u5316，\u6027\u80fd\u597d<\/td>\n | \u7565\u5feb（\u76f4\u63a5\u8c03\u7528）<\/td>\n<\/tr>\n | ||||||||||||
| Spring \u9ed8\u8ba4\u7b56\u7565<\/td>\n | \u6709\u63a5\u53e3\u7528 JDK<\/td>\n | \u65e0\u63a5\u53e3\u7528 CGLIB<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n 💡 \u52a0\u5206\u70b9： \n Q2:\u00a0Proxy.newProxyInstance\u00a0\u8fd4\u56de\u7684\u662f\u4ec0\u4e48\u5bf9\u8c61？<\/h4>\n\u7b54： \n Q3: \u52a8\u6001\u4ee3\u7406\u5728\u5b9e\u9645\u9879\u76ee\u4e2d\u7528\u5728\u54ea？<\/h4>\n\u7b54：<\/p>\n 💬 \u6211\u5728\u9879\u76ee\u4e2d\u7528 AOP + \u52a8\u6001\u4ee3\u7406\u7edf\u4e00\u5904\u7406\u63a5\u53e3\u8017\u65f6\u76d1\u63a7\u548c\u64cd\u4f5c\u65e5\u5fd7，\u51cf\u5c11\u4e86\u5927\u91cf\u91cd\u590d\u4ee3\u7801\u3002<\/p>\n \n Q4: \u4e3a\u4ec0\u4e48 JDK \u52a8\u6001\u4ee3\u7406\u5fc5\u987b\u57fa\u4e8e\u63a5\u53e3？<\/h4>\n\u7b54： \n \u2705 \u603b\u7ed3：\u4e00\u5f20\u8868\u641e\u61c2\u6838\u5fc3\u8981\u70b9<\/h3>\n
|