代理模式

结构

Subject接口

package 结构;

/**
 * @Program: 设计模式
 * @Description: Subject类定义了 RealSubject和Proxy的共用接口，
 *               这样就能在任何能够使用RealSubject的地方使用Proxy了
 * @Author Mokairui
 * @Date 2020/12/5 11:46
 */
public interface Subject {

    void request();

}

RealSubject具体实现类

package 结构;

/**
 * @Program: 设计模式
 * @Description: 定义了Proxy所代表的真实实体
 * @Author Mokairui
 * @Date 2020/12/5 11:48
 */
public class RealSubject implements Subject {

    @Override
    public void request() {
        System.out.println("真实的请求");
    }
}

代理对象

package 结构;

/**
 * @Program: 设计模式
 * @Description: 保存一个引用使得代理可以访问实体，并提供一个于Subject的接口相同的接口，
 *               这样代理就可以用来替代实体
 * @Author Mokairui
 * @Date 2020/12/5 11:50
 */
public class Proxy implements Subject {

    private RealSubject realSubject;

    @Override
    public void request() {
        if (realSubject == null) {
            realSubject = new RealSubject();
        }
        // 调用方法，但是在这里就可以就可以添加你想要的额外功能等
        realSubject.request();
    }
}

测试

package 结构;

/**
 * @Program: 设计模式
 * @Description: 测试类
 * @Author Mokairui
 * @Date 2020/12/5 12:22
 */
public class Demo {

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

}

静态代理

礼物接口

package example.静态;

/**
 * @Program: 设计模式
 * @Description: 送礼物的接口
 * @Author Mokairui
 * @Date 2020/12/5 13:43
 */
public interface IGiveGift {

    void GiveDolls();

    void GiveFlowers();

    void GiveChocolate();

}

被追求者

package example.静态;

/**
 * @Program: 设计模式
 * @Description: 被追求者
 * @Author Mokairui
 * @Date 2020/12/5 14:29
 */
public class SchoolGirl {

    private String name;

    public SchoolGirl() {
    }

    public SchoolGirl(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

}

追求者

package example.静态;

/**
 * @Program: 设计模式
 * @Description: 追求者
 * @Author Mokairui
 * @Date 2020/12/5 13:44
 */
public class Pursuit implements IGiveGift {

    private SchoolGirl schoolGirl;

    public void setSchoolGirl(SchoolGirl schoolGirl) {
        this.schoolGirl = schoolGirl;
    }

    @Override
    public void GiveDolls() {
        System.out.println(schoolGirl.getName() + "送你洋娃娃");
    }

    @Override
    public void GiveFlowers() {
        System.out.println(schoolGirl.getName() + "送你鲜花");
    }

    @Override
    public void GiveChocolate() {
        System.out.println(schoolGirl.getName() + "送你巧克力");
    }
}

代理类

package example.静态;

/**
 * @Program: 设计模式
 * @Description: 代理类
 * @Author Mokairui
 * @Date 2020/12/5 14:33
 */
public class Proxy implements IGiveGift {

    private Pursuit pursuit;

    public void setPursuit(Pursuit pursuit) {
        this.pursuit = pursuit;
    }

    @Override
    public void GiveDolls() {
        System.out.println("我是代理了送洋娃娃,我可以在这里加额外需求");
        pursuit.GiveDolls();

    }

    @Override
    public void GiveFlowers() {
        System.out.println("我是代理了送鲜花，我可以在这里加额外需求");
        pursuit.GiveFlowers();
    }

    @Override
    public void GiveChocolate() {
        System.out.println("我是代理了送巧克力，我可以再这里加额外需求");
        pursuit.GiveChocolate();
    }
}

测试

package example.静态;

/**
 * @Program: 设计模式
 * @Description: 测试类
 * @Author Mokairui
 * @Date 2020/12/5 14:36
 */
public class Demo {
    public static void main(String[] args) {
        SchoolGirl schoolGirl = new SchoolGirl("yanzi");
        Pursuit pursuit = new Pursuit();
        pursuit.setSchoolGirl(schoolGirl);

        Proxy proxy = new Proxy();
        proxy.setPursuit(pursuit);

        proxy.GiveDolls();
        System.out.println("-----------------");
        proxy.GiveFlowers();
        System.out.println("------------------");
        proxy.GiveChocolate();
    }
}

动态代理

JDK代理

追求者和被追求者，送礼物的接口这里就不重复写了

DynamicProxyHandler类

package example.动态.jdk;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;

/**
 * @Program: 设计模式
 * @Description: 动态代理对象
 * @Author Mokairui
 * @Date 2020/12/5 13:08
 */
public class DynamicProxyHandler implements InvocationHandler {

    private Pursuit pursuit;

    public DynamicProxyHandler(Pursuit pursuit) {
        this.pursuit = pursuit;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        Object result = null;
        if ("GiveDolls".equals(method.getName())) {
            // 用来区别增强的不同方法
            System.out.print("最最可爱的");
        }

        if ("GiveFlowers".equals(method.getName())) {
            // 针对不同的方法，增强不同的内容
            System.out.println("五颜六色的哦");
        }
        result = method.invoke(this.pursuit, args);

        return result;
    }

}

测试类

package example.动态.jdk;

import java.lang.reflect.Proxy;

/**
 * @Program: 设计模式
 * @Description: 测试类
 * @Author Mokairui
 * @Date 2020/12/5 13:11
 */
public class Demo {
    public static void main(String[] args) {
        Pursuit pursuit = new Pursuit();
        pursuit.setSchoolGirl(new SchoolGirl("yanzi"));

        IGiveGift proxy = (IGiveGift) Proxy.newProxyInstance(pursuit.getClass().getClassLoader()
                , pursuit.getClass().getInterfaces()
                , new DynamicProxyHandler(pursuit));

        proxy.GiveDolls();
        System.out.println("---------------------");
        proxy.GiveFlowers();
        System.out.println("---------------------");
        proxy.GiveChocolate();
    }
}

CGLIB代理

追求者的类，本来是实现接口，这里就变成了一个普通的类

package example.动态.cglib;

/**
 * @Program: 设计模式
 * @Description:
 * @Author Mokairui
 * @Date 2020/12/14 22:15
 */
public class Pursuit {

    private SchoolGift schoolGift;


    public void setSchoolGift(SchoolGift schoolGift) {
        this.schoolGift = schoolGift;
    }


    public void giveDolls() {
        System.out.println("追求者送" + schoolGift.getName() + "娃娃");
    }

    public void giveFlowers() {
        System.out.println("追求者送" + schoolGift.getName() + "鲜花");
    }

    public void giveChocolate() {
        System.out.println("追求者送" + schoolGift.getName() + "巧克力");
    }
}

代理类

package example.动态.cglib;

import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

import java.lang.reflect.Method;

/**
 * @Program: 设计模式
 * @Description:
 * @Author Mokairui
 * @Date 2020/12/14 22:26
 */
public class DynamicProxyCglibHandler implements MethodInterceptor {

    // 需要代理的对象
    private Pursuit pursuit;

    public DynamicProxyCglibHandler(Pursuit pursuit) {
        this.pursuit = pursuit;
    }

    /**
     * 代理的核心方法
     * @param proxy
     * @param method
     * @param args
     * @param methodProxy
     * @return
     * @throws Throwable
     */
    @Override
    public Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
        Object obj = null;
        System.out.println("代理方法前");
        method.invoke(pursuit, args);
        System.out.println("代理方法后");
        return obj;
    }
}

测试类

package example.动态.cglib;


import net.sf.cglib.proxy.Enhancer;


/**
 * @Program: 设计模式
 * @Description:
 * @Author Mokairui
 * @Date 2020/12/14 22:10
 */
public class Demo {

    public static void main(String[] args) {
        SchoolGift schoolGift = new SchoolGift();
        schoolGift.setName("燕子");
        Pursuit pursuit = new Pursuit();

        pursuit.setSchoolGift(schoolGift);

        Pursuit proxy = (Pursuit) Enhancer.create(pursuit.getClass(),
                new DynamicProxyCglibHandler(pursuit));

        proxy.giveDolls();
        System.out.println("-----------------");
        proxy.giveFlowers();
        System.out.println("----------------");
        proxy.giveChocolate();

    }

}

posted on 2020-12-20 21:24 莫铠瑞阅读(51) 评论(0) 收藏举报