静态代理:客户,中介,房东租房场景的例子:
//抽象的接口类
package cn.thomson.proxy;
public interface rent {
public void rent();}
//房东出租此屋
package cn.thomson.proxy;
public class Host implements rent {public void rent(){
System.out.println("出租此屋");
}
//中介租屋
package cn.thomson.proxy;
public class Proxy implements rent{
private Host host;
public Proxy(Host host) {
this.host=host;
}
public void rent(){
seeHouse();
host.rent();
getMoney();
}
public void seeHouse(){
System.out.println("参观此屋");
}
public void getMoney(){
System.out.println("收取中介费");
}
}
租房客户(测试类)
package cn.thomson.proxy;
public class Customer {
public static void main(String[] args) {
Host host=new Host();
Proxy proxy=new Proxy(host);
proxy.rent();
}
}
中介只具有参观此屋和收取中介费的功能。但是打印信息如下:
此为静态代理模式。代理和代理对象实现相同的抽象方法。
+++++++++++++++++++++++++++++++++++++++++++++++++++++++
动态代理模式:
//抽象类
package ProxyFactory;
public interface IUserDao {
void save();
}
//实现抽象方法
package ProxyFactory;
public class UserDao implements IUserDao {
@Override
public void save() {
// TODO Auto-generated method stub
System.out.println("已经保存数据");
}
}
//代理类
package ProxyFactory;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;public class proxyFactory {
//目标对象
private Object target;
public proxyFactory(Object target) {
super();
this.target = target;
}
//目标对象和代理对象关联
public Object getInstance(){
return Proxy.newProxyInstance(target.getClass().getClassLoader(), target.getClass().getInterfaces(), new InvocationHandler(){
@Override
public Object invoke(Object proxy, Method method, Object[] args)
throws Throwable {
System.out.println(“事物1”);
Object obj=method.invoke(target, args);
System.out.println(“事物2”);
return obj;
}});}
}
//测试类
package ProxyFactory;
public class Test {
public static void main(String[] args) {
// TODO Auto-generated method stub
//目标对象
IUserDao target=new UserDao();
IUserDao proxy=(IUserDao)new proxyFactory(target).getInstance();
proxy.save();
}
}
测试结果为: