动态代理模式的角色：
--抽象角色：是真实对象和代理对象的公共接口
--代理角色：对真实对象进行封装，可以操作真实对象
--真实角色：依赖代理角色，代理真正操纵的类
抽象角色：
subject.java
package com.wansha.proxy;
public interface Subject {
public void request();
}
真实角色：
Subject1.java
package com.wansha.proxy;
public class Subject1 implements Subject {
@Override
public void request() {
System.out.println("Subject1");
}
}
Subject2.java
package com.wansha.proxy;
public class Subject2 implements Subject {
@Override
public void request() {
System.out.println("Subject2");
}
}
生成代理角色的实现类
ProxySubject.java
package com.wansha.proxy;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
public class ProxySubject implements InvocationHandler {
private Object obj;
public ProxySubject(Object obj){
this.obj = obj;
}
public ProxySubject(){
}
@Override
public Object invoke(Object proxy, Method method, Object[] args)
throws Throwable {
System.out.println("代理方法执行之前");
method.invoke(obj,args);
System.out.println("代理方法执行之后");
return null;
}
public void setObj(Object obj) {
this.obj = obj;
}
public Object getfactory()throws Exception{
if(obj == null){
throw new Exception("没有目标对象");
}
return Proxy.newProxyInstance(obj.getClass().getClassLoader(),obj.getClass().getInterfaces(),new ProxySubject(obj));//生成代理角色
}
}
客户端：
Client.java
package com.wansha.proxy;
import java.lang.reflect.Proxy;
public class Client {
public static void main(String[] args) throws Exception{
realSubject real = new realSubject();
Subject1 real1 = new Subject1();
Subject2 real2 = new Subject2();
ProxySubject proSub= new ProxySubject();
proSub.setObj(real);
Subject sub = (Subject)proSub.getfactory();
sub.request();
}
}