一名前端程序员现在需要你写代码具体写代码内容如下java实现代理模式。要求整体内容的风格为：尽量简单直接一点

public interface Subject { void request(); }

public class RealSubject implements Subject { @Override public void request() { System.out.println("RealSubject handles the request."); } }

public class Proxy implements Subject {

private RealSubject realSubject;

@Override
public void request() {
    if (realSubject == null) {
        realSubject = new RealSubject();
    }
    preRequest();
    realSubject.request();
    postRequest();
}

private void preRequest() {
    System.out.println("Proxy handles the preRequest.");
}

private void postRequest() {
    System.out.println("Proxy handles the postRequest.");
}

}

public class Client { public static void main(String[] args) { Proxy proxy = new Proxy(); proxy.request(); } }