Spring AOP的默认代理方式是jdk动态代理,还有另外一种代理方式是cglib代理,简单说前者基于接口,后者基于继承,基本思路是将被代理对象的类作为父类,然后创建子类来进行方法的调用,调用的同时可以插入我们需要加入的方法。
二:
(1)pojo类
package net.wang.cglib;
/**
* User pojo类
* @author LiuRuoWang
*/
public class User {
private Integer id;
private String name;
public void setId(Integer id) {
this.id = id;
}
public Integer getId() {
return id;
}
public void setName(String name) {
this.name = name;
}
public String getName() {
return name;
}
}
(2)接口UserService
package net.wang.cglib;
public interface UserService {
public void addUser(User user);
public User getUser(int id);
}
(3)实现类UserServiceImpl
package net.wang.cglib;
public class UserServiceImpl implements UserService{
public void addUser(User user) {
System.out.println("add User!");
}
public User getUser(int id) {
User user=new User();
user.setId(id);
System.out.println("get User!");
return user;
}
}
(4)中间类CGProxy,需实现MethodInterceptor接口
package net.wang.cglib;
import Java.lang.reflect.Method;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;
public class CGProxy implements MethodInterceptor{
//代理对象
private Object target;
public CGProxy(Object target) {
this.target=target;
}
public Object getProxyObject(){
Enhancer enhancer = new Enhancer();
//设置被代理对象类为父类
enhancer.setSuperclass(target.getClass());
//回调intercept方法
enhancer.setCallback(this);
//创建代理对象
return enhancer.create();
}
public Object intercept(Object arg0, Method arg1, Object[] arg2,
MethodProxy arg3) throws Throwable {
System.out.println("do sth before!");
Object result=arg3.invokeSuper(arg0, arg2);
System.out.println("do sth after!");
return result;
}
}
(5)测试
package net.wang.cglib;
public class CGProxyTest {
public static void main(String[] args) {
//被代理对象
Object proxyedObject = new UserServiceImpl();
CGProxy cgProxy = new CGProxy(proxyedObject);
UserService proxyObject = (UserService) cgProxy.getProxyObject();
proxyObject.getUser(1);
proxyObject.addUser(new User());
}
}
以上代码继承接口,并不是代表着基于jdk动态代理方式,只是纯粹的面向接口编程,具体是哪种代理方式,还需看中间类的具体实现。
结果:
Spring AOP自定义注解方式实现日志管理