接口的应用：代理模式

/*
接口的应用:代理模式
 */
public class NetWorkTest {
    public static void main(String[] args) {
        Server server = new Server();
        new ProxyServer(server);
        ProxyServer proxyServer = new ProxyServer(server);
        proxyServer.browse();
    }
}
interface NetWork{
    public void browse();
}
//被代理类
class Server implements NetWork{

    @Override
    public void browse() {
        System.out.println("真实的服务器访问网络");
    }
}
//代理类
class ProxyServer implements NetWork{
    private NetWork work;
    public ProxyServer(NetWork work){//对属性进行初始化
        this.work=work;
    }
    public void check(){
        System.out.println("联网之前的检查工作");
    }
    @Override
    public void browse() {
        check();
        work.browse();
    }
}