java 各种 proxy 示例

Author: YunaiV

README.md

@@ -397,10 +397,10 @@
 
 如下是草稿目录，未来需要整理下
 
-# lab-9
-
-记录阅读极客时间《数据结构与算法之美》的题目。
-
 # lab-50
 
 Email 示例
+
+# lab-69-proxy
+
+动态代理

lab-69-proxy/lab-69-proxy-cglib/pom.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+ xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+ <parent>
+ <artifactId>lab-69</artifactId>
+ <groupId>cn.iocoder.springboot.labs</groupId>
+ <version>1.0-SNAPSHOT</version>
+ </parent>
+ <modelVersion>4.0.0</modelVersion>
+
+ <artifactId>lab-69-proxy-cglib</artifactId>
+
+ <dependencies>
+ <dependency>
+ <groupId>cglib</groupId>
+ <artifactId>cglib</artifactId>
+ <version>3.3.0</version>
+ </dependency>
+ </dependencies>
+
+</project>

lab-69-proxy/lab-69-proxy-cglib/src/main/java/cn/iocoder/springboot/labs/lab69/TestProxyMain.java

@@ -0,0 +1,19 @@
+package cn.iocoder.springboot.labs.lab69;
+
+import cn.iocoder.springboot.labs.lab69.intercept.UserServiceMethodInterceptor;
+import cn.iocoder.springboot.labs.lab69.service.UserServiceImpl;
+import net.sf.cglib.proxy.Enhancer;
+
+public class TestProxyMain {
+
+ public static void main(String[] args) {
+ // 创建 cglib 增强对象
+ Enhancer enhancer = new Enhancer();
+ enhancer.setSuperclass(UserServiceImpl.class); // 设置父类
+ enhancer.setCallback(new UserServiceMethodInterceptor());
+ // 创建代理
+ UserServiceImpl userService = (UserServiceImpl) enhancer.create();
+ userService.create("yunai", "buzhidao");
+ }
+
+}

lab-69-proxy/lab-69-proxy-cglib/src/main/java/cn/iocoder/springboot/labs/lab69/intercept/UserServiceMethodInterceptor.java

@@ -0,0 +1,17 @@
+package cn.iocoder.springboot.labs.lab69.intercept;
+
+import net.sf.cglib.proxy.MethodInterceptor;
+import net.sf.cglib.proxy.MethodProxy;
+
+import java.lang.reflect.Method;
+
+public class UserServiceMethodInterceptor implements MethodInterceptor {
+
+ public Object intercept(Object object, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
+ System.out.println("before invoke");
+ Object ret = methodProxy.invokeSuper(object, args);
+ System.out.println("after invoke");
+ return ret;
+ }
+
+}

lab-69-proxy/lab-69-proxy-cglib/src/main/java/cn/iocoder/springboot/labs/lab69/service/UserServiceImpl.java

@@ -0,0 +1,9 @@
+package cn.iocoder.springboot.labs.lab69.service;
+
+public class UserServiceImpl {
+
+ public void create(String username, String password) {
+ System.out.println(String.format("登陆的用户名(%s) 密码(%s)", username, password));
+ }
+
+}

lab-69-proxy/lab-69-proxy-jdk/pom.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+ xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+ <parent>
+ <artifactId>lab-69</artifactId>
+ <groupId>cn.iocoder.springboot.labs</groupId>
+ <version>1.0-SNAPSHOT</version>
+ </parent>
+ <modelVersion>4.0.0</modelVersion>
+
+ <artifactId>lab-69-proxy-jdk</artifactId>
+
+ <dependencies>
+ <dependency>
+ <groupId>commons-io</groupId>
+ <artifactId>commons-io</artifactId>
+ <version>2.7</version>
+ </dependency>
+ </dependencies>
+
+</project>

lab-69-proxy/lab-69-proxy-jdk/src/main/java/cn/iocoder/springboot/labs/lab69/GenerateProxyMain.java

@@ -0,0 +1,25 @@
+package cn.iocoder.springboot.labs.lab69;
+
+import cn.iocoder.springboot.labs.lab69.service.UserServiceImpl;
+import org.apache.commons.io.IOUtils;
+import sun.misc.ProxyGenerator;
+
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.lang.reflect.Proxy;
+
+/**
+ * 生成 JDK {@link Proxy} 的示例代码
+ *
+ * 生成后，我们可以反编译查看具体的类
+ */
+public class GenerateProxyMain {
+
+ public static void main(String[] args) throws IOException {
+ // 生成字节码
+ byte[] classFile = ProxyGenerator.generateProxyClass("$Proxy11", UserServiceImpl.class.getInterfaces());
+ // 写入到磁盘
+ IOUtils.write(classFile, new FileOutputStream("/Users/yunai/ls/$Proxy11.class"));
+ }
+
+}

lab-69-proxy/lab-69-proxy-jdk/src/main/java/cn/iocoder/springboot/labs/lab69/TestProxyMain.java

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+package cn.iocoder.springboot.labs.lab69;
+
+import cn.iocoder.springboot.labs.lab69.handler.UserServiceHandler;
+import cn.iocoder.springboot.labs.lab69.service.UserService;
+import cn.iocoder.springboot.labs.lab69.service.UserServiceImpl;
+
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Proxy;
+
+/**
+ * 使用 JDK {@link Proxy} 实现一个动态代理的示例
+ */
+public class TestProxyMain {
+
+ public static void main(String[] args) {
+ // 创建 UserService 对象
+ UserService userService = new UserServiceImpl();
+ // JDK 处理器
+ InvocationHandler handler = new UserServiceHandler(userService);
+ // 创建代理
+ UserService userServiceProxy = (UserService) Proxy.newProxyInstance(TestProxyMain.class.getClassLoader(), userService.getClass().getInterfaces(), handler);
+ // 执行
+ userServiceProxy.create("yunai", "buzhidao");
+ }
+
+}

lab-69-proxy/lab-69-proxy-jdk/src/main/java/cn/iocoder/springboot/labs/lab69/handler/UserServiceHandler.java

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+package cn.iocoder.springboot.labs.lab69.handler;
+
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
+
+public class UserServiceHandler implements InvocationHandler {
+
+ /**
+ * 被代理的对象
+ */
+ private final Object object;
+
+ public UserServiceHandler(Object object) {
+ this.object = object;
+ }
+
+ public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
+ System.out.println("before invoke");
+ Object ret = method.invoke(object, args);
+ System.out.println("after invoke");
+ return ret;
+ }
+
+}

lab-69-proxy/lab-69-proxy-jdk/src/main/java/cn/iocoder/springboot/labs/lab69/service/UserService.java

@@ -0,0 +1,7 @@
+package cn.iocoder.springboot.labs.lab69.service;
+
+public interface UserService {
+
+ void create(String username, String password);
+
+}