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这里我们就需要用到cglib-nodep-2.1_3.jar这个包

下面代码是演示的是一个用户权限判断，并赋予这个用户相应的操作。这里我做的是这样的用户权限设置：只要用户名不为空，那么就赋予它操作目标类中的所有方法的权利

代码一：

package cn.itcast.service;
public interface IPersonService {
public void save(String name);
}

代码二 CGlibProxyFactory.java和JDKProxyFactory.java

package cn.itcast.service.aop;
import java.lang.reflect.Method;
import cn.itcast.service.impl.personServiceBean;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;
public class CGlibProxyFactory implements MethodInterceptor{
private Object targetObject;
public Object createProxyIntance(Object targetObject){
this.targetObject = targetObject;
Enhancer enhancer = new Enhancer();
enhancer.setSuperclass(this.targetObject.getClass());//CGlib是集成目标类，然后覆盖目标类中的非final方法，这样达到代理的效果
enhancer.setCallback(this);
return enhancer.create();
}
public Object intercept(Object proxy, Method method, Object[] args,
MethodProxy methodProxy) throws Throwable {
personServiceBean bean =(personServiceBean) this.targetObject;
Object result = null;
if(bean.getUser()!=null){
//advice -->AOP术语：前置通知
try {
result = methodProxy.invoke(targetObject, args);
//afteradvice-->AOP术语：后置通知
} catch (Exception e) {
//Exceptionadvice-->AOP术语：例外通知
}finally{
//finallyadvice-->AOP术语：最终通知
}
}
return result;
}
}

package cn.itcast.service.aop;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import cn.itcast.service.impl.personServiceBean2;
public class JDKProxyFactory implements InvocationHandler{
private Object targetObject;
public Object createProxyIntance(Object targetObject){
this.targetObject =targetObject;
return Proxy.newProxyInstance(this.targetObject.getClass().getClassLoader()
, this.targetObject.getClass().getInterfaces(), this);
}
public Object invoke(Object arg0, Method arg1, Object[] arg2)
throws Throwable {
personServiceBean2 bean =(personServiceBean2) this.targetObject;
Object result = null;
if(bean.getUser()!=null){
result = arg1.invoke(targetObject, arg2);
}
return result;
}
}

代码三：personServiceBean.java和personServiceBean2.java

package cn.itcast.service.impl;
import cn.itcast.service.IPersonService;
public class personServiceBean  {
private String user ;

public String getUser() {
return user;
}
public personServiceBean() {
}

public personServiceBean(String user) {
this.user = user;
}

public String getPersonName(Integer personId) {
return "postino";
}

public void save(String name) {
System.out.println("这是save方法");
}
}

package cn.itcast.service.impl;
import cn.itcast.service.IPersonService;
public class personServiceBean2 implements IPersonService {
private String user ;
public String getUser() {
return user;
}
public personServiceBean2() {
}
public personServiceBean2(String user) {
this.user = user;
}
public String getPersonName(Integer personId) {
return "postino";
}
public void save(String name) {
System.out.println("这是save方法");
}
public void update(String name, Integer personId) {
System.out.println("这是update方法");
}
}

测试类：AOPTest.java

package junit.test;
import static org.junit.Assert.*;
import org.junit.BeforeClass;
import org.junit.Test;
import cn.itcast.service.aop.CGlibProxyFactory;
import cn.itcast.service.aop.JDKProxyFactory;
import cn.itcast.service.impl.personServiceBean;
import cn.itcast.service.impl.personServiceBean2;
import cn.itcast.service.IPersonService;
public class AOPTest {
@BeforeClass
public static void setUpBeforeClass() throws Exception {
}
@Test public void proxyTest(){
JDKProxyFactory jdkpf = new JDKProxyFactory();
IPersonService ipersonService = (IPersonService)jdkpf.createProxyIntance(new personServiceBean2(""));
ipersonService.save("");
}
@Test public void proxyTest2(){
CGlibProxyFactory jdkpf = new CGlibProxyFactory();
personServiceBean service = (personServiceBean)jdkpf.createProxyIntance(new personServiceBean(""));
service.save("");
}
}

学习总结：
1:JDKProxy拦截是，通过新建一个Proxy对象来实现的，里面传入三个参数，一个目标类的类加载器，一个目标类实现了的接口，一个目标类对象Proxy.newProxyInstance(this.targetObject.getClass().getClassLoader() , this.targetObject.getClass().getInterfaces(), this);

2：CGlib是通过定义Enhancer类的对象，然后覆盖目标类的非final方法实现的集成，在通过回调

3：如果是用JDKProxy实现拦截，那么目标类必须是面向接口编程。而CGlib则不需要