java代理的两种实现
package dao;public interface BookFacade { public void addBook(); }--------------------------------package dao.impl;import dao.BookFacade;public class BookFacadeImpl implements BookFacade { public void addBook() { System.out.println("add by jdk proxy"); } } --------------------------------package proxy;import java.lang.reflect.InvocationHandler; import java.lang.reflect.Method; import java.lang.reflect.Proxy; //JDK动态代理代理类 public class BookFacadeProxy implements InvocationHandler { private Object target; /** * 绑定委托对象并返回一个代理类 * @param target * @return */ public Object bind(Object target) { this.target = target; //取得代理对象 return Proxy.newProxyInstance(target.getClass().getClassLoader(), target.getClass().getInterfaces(), this); //要绑定接口(这是一个缺陷，cglib弥补了这一缺陷) } /** * 调用方法 */ public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { Object result=null; System.out.println("事物开始"); //执行方法 result=method.invoke(target, args); System.out.println("事物结束"); return result; } } --------------------------package proxy;import dao.BookFacade;import dao.impl.*;// 使用JDK的动态代理必须依靠接口实现public class TestProxy { public static void main(String[] args) { BookFacadeProxy proxy = new BookFacadeProxy(); BookFacade bookProxy = (BookFacade) proxy.bind(new BookFacadeImpl()); bookProxy.addBook(); } } /*以上为java反射下的代理*/-------------------------------------------package dao.cglib;public class BookFacade { //未使用接口 public void addBook() { System.out.println("add by Cglib."); } } --------------------------------------------package proxy;import java.lang.reflect.Method; import net.sf.cglib.proxy.Enhancer; import net.sf.cglib.proxy.MethodInterceptor; import net.sf.cglib.proxy.MethodProxy; // 实现MethodInterceptor的intercept(拦截器)public class BookFacadeCglib implements MethodInterceptor { private Object target; //创建代理对象 public Object getInstance(Object target) { this.target = target; Enhancer enhancer = new Enhancer(); enhancer.setSuperclass(this.target.getClass()); // 回调方法 enhancer.setCallback(this); // 创建代理对象 return enhancer.create(); } // 回调方法 (拦截器:默认拦截子类)--在这里可以做很多的文章哦 public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable { System.out.println("Begin"); proxy.invokeSuper(obj, args); //obj调用对象，args参数列表 System.out.println("End"); return null; } }----------------------------------------package proxy;import dao.cglib.BookFacade;//使用cglib的代理public class TestCglib { public static void main(String[] args) { BookFacadeCglib cglib=new BookFacadeCglib(); BookFacade bookCglib=(BookFacade)cglib.getInstance(new BookFacade()); bookCglib.addBook(); } }