01_静态代理

张创琦

方法1：通过extends继承代理

缺点：只能继承自一个父类。继承数量有限

TeamService.java

package com.kkb.service;
public class TeamService {
    @Override
    public void add(){
            System.out.println("TeamService--------add-------");
    }
}

ProxyTeamService.java

继承自TeamService.java

package com.kkb.service.staticproxy;
import com.kkb.service.TeamService;
public class ProxyTeamService extends TeamService {
    public void add() {
        try{
            System.out.println("开始事务");
            super.add();
            System.out.println("提交事务");
        } catch(Exception e) {
            System.out.println("回滚事务");
        }
    }
}

test类

public void test02(){
    ProxyTeamService proxyTeamService = new ProxyTeamService();
    proxyTeamService.add();
}

方法2：通过implements接口代理

2.1：代理类和被代理类实现同一个接口

IService.java

package com.kkb.service;
/**
 * 接口定义核心方法
 *
 */
public interface IService {
    void add();
}

UserService.java

package com.kkb.service;
public class UserService implements IService {
    @Override
    public void add() {
        System.out.println("UserService------add------");
    }
}

代理类和被代理类实现同一个接口

ProxyTranService.java

package com.kkb.service.staticproxy;
import com.kkb.service.IService;
/**
 * 基于接口的静态代理
 * 代理类和被代理类实现同一个接口
 */
public class ProxyTranService implements IService {
    private IService service;  //被代理的对象
    public ProxyTranService(IService service) {
        this.service = service;
    }
    @Override
    public void add() {
        try{
            System.out.println("开始事务");
            service.add();
            System.out.println("提交事务");
        } catch(Exception e) {
            System.out.println("回滚事务");
        }
    }
}

Test

@Test
public void test03(){
    UserService userService = new UserService();
    ProxyTranService tranService = new ProxyTranService(userService);//一级代理
    tranService.add();
}

2.2：多级代理模式

ProxyLogService.java

package com.kkb.service.staticproxy;
import com.kkb.service.IService;
public class ProxyLogService implements IService {
    private IService service;
    public ProxyLogService(IService service) {
        this.service = service;
    }
    @Override
    public void add() {
        try{
            System.out.println("开始日志");
            service.add();
            System.out.println("结束日志");
        } catch(Exception e) {
            System.out.println("异常日志");
        }
    }
}

Test

public static void main(String[] args) {
    UserService userService = new UserService();
    ProxyTranService tranService = new ProxyTranService(userService);//一级代理
    ProxyLogService logService = new ProxyLogService(tranService);//二级代理
    logService.add(); 
}