JDK中Proxy实现切面编程

切面编程：对类中的方法设置权限

JDK中Proxy实现AOP举例

PersonService.java

package com.aop.service;

public interface PersonService {
public String getUser();
public void save();
public void update();
}

PersonServiceImpl.java

package com.aop.service.impl;

import com.aop.service.PersonService;

public class PersonServiceImpl implements PersonService{
private String user = null;

public PersonServiceImpl() {
}

public PersonServiceImpl(String user){
this.user = user;
}
public String getUser() {
return user;
}

public void save() {

System.out.println("save()");
}

public void update() {
System.out.println("update()");

}
}

JDKProxyFactory.java

package com.aop.factory;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

import com.aop.service.impl.PersonServiceImpl;

public class JDKProxyFactory implements InvocationHandler {
private Object targetObject;
public Object createProxyInstance(Object targetObject){
this.targetObject = targetObject;
return Proxy.newProxyInstance(this.targetObject.getClass().getClassLoader(),
this.targetObject.getClass().getInterfaces(), this);
}
@Override
public Object invoke(Object proxy, Method method, Object[] args)
throws Throwable {
PersonServiceImpl service = (PersonServiceImpl) this.targetObject;
Object result = null;
if(service.getUser() != null){
result = method.invoke(targetObject, args);
}
return result;
}
}

测试类：AOPTest.java

package com.aop.junit;

import com.aop.factory.JDKProxyFactory;
import com.aop.service.PersonService;
import com.aop.service.impl.PersonServiceImpl;

public class AOPTest {

public static void main(String[] args) {
JDKProxyFactory factory = new JDKProxyFactory();
PersonService service = (PersonService) factory.createProxyInstance(new PersonServiceImpl());
service.save();

}
}