SpringAOP-代理模式

proxy.png uml.png

客户端与接口交互
proxy与具体类都需事先接口
proxy用于额外实现织入的内容

例子

接口类

public interface Subject {
    void request();
    void hello();
}

真正实现类

public class RealSubject implements Subject{
    @Override
    public void request() {
        System.out.println("real subject execute request");
    }

    @Override
    public void hello() {
        System.out.println("hello");
    }
}

代理类

public class Proxy implements Subject{

// 代理类中引用实际实现类
    private RealSubject realSubject;

    public Proxy(RealSubject realSubject) {
        this.realSubject = realSubject;
    }

// 在实际对象执行相应逻辑的前后通过代理对象添加额外的逻辑功能
    @Override
    public void request() {
        System.out.println("before");
        try{
            realSubject.request();
        }catch (Exception e){
            System.out.println("ex:"+e.getMessage());
            throw e;
        }finally {
            System.out.println("after");
        }
    }

    @Override
    public void hello() {
        realSubject.hello();
    }
}

客户端

public class Client {

    public static void main(String[] args){
        Subject subject = new Proxy(new RealSubject());
        subject.request();
    }
}