代理模式6（9）

隐藏真实访问对象，对外代理对象

package structural;

public class ProxyMain {

    public static void main(String[] args) {
        ProxySubject proxy = new ProxySubject();
        proxy.getRequest();
    }

}

interface Subject{
    void getRequest();
}

class RealSubject implements Subject{

    @Override
    public void getRequest() {
        System.out.println("你访问到真的我了！");
    }
    
}

class ProxySubject implements Subject{

    private RealSubject realSubject;
    @Override
    public void getRequest() {
        
        if(realSubject == null){
            realSubject = new RealSubject();
        }
        
        preRequest();
        realSubject.getRequest();
        endRequest();
        
    }
    private void preRequest() {
        System.out.println("处理前！");
    }
    private void endRequest() {
        System.out.println("处理后！");
    }
    
    
}