编译阶段不用关心代理的类，运行阶段才指定代理哪一个对象。
InvocationHandler接口是JDK提供的动态代理接口，
自定义动态代理类实现InvocationHandler接口。
invoke方法是必须实现的，它完成对真实方法的调用，
给定一个接口，动态代理会宣称“已经实现该接口的所有方法了，”动态代理怎么实现被代理接口中的方法呢?
通过InvocationHandler接口，所有方法都通过Handler处理，即所有被代理的方法都由InvocationHandler接管实际的处理任务。
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| public class GamePlayerIH implements InvocationHandler {
Object object = null;
public GamePlayerIH(Object object) {
this.object = object;
}
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
return method.invoke(object, args);
}
}
public class Client {
public static void main(String[] args) {
iGamePlayer gamePlayer = new GamePlayer("张三");
InvocationHandler handler = new GamePlayerIH(gamePlayer);
iGamePlayer proxyInstance = (iGamePlayer) Proxy.newProxyInstance(gamePlayer.getClass().getClassLoader(),gamePlayer.getClass().getInterfaces(), handler);
proxyInstance.login("zs","123");
proxyInstance.killBoss();
proxyInstance.update();
}
}
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第二种方式
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| public class AutoProxy implements InvocationHandler {
private Singer singer;
public Object getproxy(Singer singer) {
this.singer = singer;
Object instance = Proxy.newProxyInstance(singer.getClass().getClassLoader(), singer.getClass().getInterfaces(), this);
return instance;
}
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
System.out.println("前置通知");
Object invoke = method.invoke(singer);
System.out.println("后置通知");
return invoke;
}
}
Client端
Star star = (Star) new AutoProxy().getproxy(new Singer());
star.show();
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第三种方式
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| public class GamePlayerIH {
Object object = null;
public GamePlayerIH(Object object) {
this.object = object;
}
public Object getproxyInstance() {
return Proxy.newProxyInstance(object.getClass().getClassLoader(),object.getClass().getInterfaces(), new InvocationHandler() {
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
if (method.getName().equalsIgnoreCase("login")) {
System.out.println("快上号看看!!!有人登录你的账号了！！！");
}
return method.invoke(object, args);
}
});
}
}
Client
iGamePlayer gamePlayer = new GamePlayer("zs");
GamePlayerIH gamePlayerIH = new GamePlayerIH(gamePlayer);
iGamePlayer instance = (iGamePlayer)gamePlayerIH.getproxyInstance();
instance.login("zs","123");
instance.killBoss();
instance.update();
|
参考博客
动态代理
