Java设计模式之代理模式详解

// 抽象主题
public interface Subject {
    void request();
}
// 真实主题
public class RealSubject implements Subject {
    @Override
    public void request() {
        System.out.println("RealSubject is performing the request.");
    }
}
// 代理
public class Proxy implements Subject {
    private RealSubject realSubject;
    public Proxy(RealSubject realSubject) {
        this.realSubject = realSubject;
    }
    @Override
    public void request() {
        System.out.println("Proxy is performing additional operations before the request.");
        realSubject.request();
        System.out.println("Proxy is performing additional operations after the request.");
    }
}

// 安全代理例子
Proxy proxy = new Proxy(new RealSubject());
proxy.request(); // 通过代理进行安全性控制