Java静态代理和动态代理总结

public interface Hello { void say(String msg);}

public class HelloImpl implements Hello { public void say(String msg) {  System.out.println("Hi,"+msg); }}

public class HelloProxy implements Hello{ private Hello hello; public HelloProxy(Hello hello){  this.hello = hello; } public void say(String msg){  before();  hello.say(msg);  after(); } private void before(){  System.out.println("Before"); } private void after(){  System.out.println("After"); }}

/** * @Author LZHL * @Create 2017-02-19 10:26 * @Description */public class Main { public static void main(String[] args) throws Exception {  HelloImpl target = new HelloImpl();  HelloProxy proxy = new HelloProxy(target);  proxy.say("LZHL"); }}

public class HelloTarget { public void sayHello(String name){  System.out.println("Hi,"+name); }}

public class HelloProxy extends HelloTarget{　　private HelloTarget target;　　public HelloProxy(HelloTarget target){　　　　this.target = target;　　} 　　@Override public void sayHello(String name) {  this.before();  target.sayHello(name);  this.after(); } private void before(){  System.out.println("Before"); } private void after(){  System.out.println("After"); }}

public class Main { public static void main(String[] args) throws Exception {  HelloTarget target = new HelloTarget(); 　　　　HelloProxy proxy= new HelloProxy(target);  proxy.sayHello("LZHL"); }}

/** * @Author LZHL * @Create 2017-02-19 12:46 * @Description */public class Main { public static void main(String[] args){  final HelloImpl target = new HelloImpl();  Object proxyInstance = Proxy.newProxyInstance(target.getClass().getClassLoader(), target.getClass().getInterfaces(), new InvocationHandler() {   /*    * proxy: 代理对象    * method: 目标对象的方法对象    * args: 目标对象方法的参数    * return: 目标对象方法的返回值    */   public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {    System.out.println("before");    Object retValue = method.invoke(target, args);    System.out.println("after");    return retValue;   }  });  Hello proxy = (Hello) proxyInstance;  proxy.say("LYX");  //可以把InvocationHandler提取出来，单独写一个类，为了方便大家看，这里我用内部类的形式  class JDKProxy implements InvocationHandler {   private Object target;   public JDKProxy(Object target){    this.target = target;   }   public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {    before();    Object result = method.invoke(target, args);    after();    return result;   }   private void before(){    System.out.println("Before");   }   private void after(){    System.out.println("After");   }  }  InvocationHandler ih = new JDKProxy(target);  Object proxyInstance2 = Proxy.newProxyInstance(target.getClass().getClassLoader(), target.getClass().getInterfaces(), ih);  Hello proxy2 = (Hello) proxyInstance2;  proxy2.say("LZHL"); }}

<dependencies> <!-- https://mvnrepository.com/artifact/cglib/cglib --> <dependency>  <groupId>cglib</groupId>  <artifactId>cglib</artifactId>  <version>3.2.4</version> </dependency></dependencies>

public class Hi { public void sayHi(String msg){  System.out.println("Hi,"+msg); }}

/** * @Author LZHL * @Create 2017-02-19 13:19 * @Description */public class Main { public static void main(String[] args) {  Enhancer enhancer = new Enhancer();  //设置父类  enhancer.setSuperclass(Hi.class);  //设置回调函数  enhancer.setCallback(new MethodInterceptor() {   public Object intercept(Object target, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {    System.out.println("before");    Object retValue = methodProxy.invokeSuper(target, args);    System.out.println("after");    return retValue;   }  });  Object proxy = enhancer.create();  Hi hi = (Hi) proxy;  hi.sayHi("LXY");  //可以把MethodInterceptor提取出来，单独写一个类，为了方便大家看，这里我用内部类的形式  class CGLibProxy implements MethodInterceptor {   public <T> T getProxy(Class<T> clazz){    return (T) Enhancer.create(clazz, this);   }   public Object intercept(Object target, Method method, Object[] args, MethodProxy proxy) throws Throwable {    before();    Object result = proxy.invokeSuper(target, args);    after();    return result;   }   private void before(){    System.out.println("Before");   }   private void after(){    System.out.println("After");   }  }  CGLibProxy cgLibProxy = new CGLibProxy();  Hi hi2 = cgLibProxy.getProxy(Hi.class);  hi2.sayHi("LZHL"); }}