本文已参与「新人创作礼」活动，一起开启掘金创作之路。
代理模式：
静态代理
优缺点
代码结构
Code实现
/*******************************************************************************
* Package: com.example.demo.design.proxy.staticproxy
* Type: ILog
* Date: 2022-04-10 13:40
*
* Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
*
* You may not use this file except in compliance with the License.
*******************************************************************************/
package com.example.demo.design.proxy.staticproxy;
/**
* 功能描述： 日志接口
* 静态代理：
* 优点：对目标方法 功能增强
* 缺点：不易于维护
* @author Songxianyang
* @date 2022-04-10 13:40
*/
public interface ILog {
/**
* 打印日志
*/
void pint();
}
/*******************************************************************************
* Package: com.example.demo.design.proxy.staticproxy
* Type: ILogImpl
* Date: 2022-04-10 13:40
*
* Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
*
* You may not use this file except in compliance with the License.
*******************************************************************************/
package com.example.demo.design.proxy.staticproxy;
/**
* 功能描述：
*
* @author Songxianyang
* @date 2022-04-10 13:40
*/
public class LogImpl implements ILog {
@Override
public void pint() {
System.out.println("打印日志");
}
}
/*******************************************************************************
* Package: com.example.demo.design.proxy.staticproxy
* Type: LogProxy
* Date: 2022-04-10 13:42
*
* Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
*
* You may not use this file except in compliance with the License.
*******************************************************************************/
package com.example.demo.design.proxy.staticproxy;
/**
* 功能描述：
* 实现对方法的增强
* @author Songxianyang
* @date 2022-04-10 13:42
*/
public class LogProxy implements ILog {
private ILog iLog;
public LogProxy(ILog iLog) {
this.iLog = iLog;
}
@Override
public void pint() {
//这边写的可以是业务方法：比喻：事务的开启
System.out.println("开启事务-----");
//执行目标方法:可以做判断 是否有异常 有 回滚 无 提交
iLog.pint();
//假设 无
System.out.println("提交事务-----");
}
}
/*******************************************************************************
* Package: com.example.demo.design.proxy.staticproxy
* Type: Test
* Date: 2022-04-10 13:47
*
* Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
*
* You may not use this file except in compliance with the License.
*******************************************************************************/
package com.example.demo.design.proxy.staticproxy;
/**
* 功能描述：
*
* @author Songxianyang
* @date 2022-04-10 13:47
*/
public class Test {
public static void main(String[] args) {
// 目标类
ILog log = new LogImpl();
// 代理类
LogProxy proxy = new LogProxy(log);
// 调用代理中的方法
proxy.pint();
}
}
运行截图
动态代理
结构
/*******************************************************************************
* Package: com.example.demo.design.proxy.staticproxy
* Type: ILog
* Date: 2022-04-10 13:40
*
* Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
*
* You may not use this file except in compliance with the License.
*******************************************************************************/
package com.example.demo.design.proxy.dynamic;
/**
* 功能描述： 日志接口
* 动态代理：jdk 代理 接口代理
* 优点：对目标方法 功能增强
* 缺点：易于维护
* @author Songxianyang
* @date 2022-04-10 13:40
*/
public interface ILog {
/**
* 打印日志
*/
void pint();
/**
* 打印一个数
*/
void num( int i);
int count(int j);
}
/*******************************************************************************
* Package: com.example.demo.design.proxy.staticproxy
* Type: ILogImpl
* Date: 2022-04-10 13:40
*
* Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
*
* You may not use this file except in compliance with the License.
*******************************************************************************/
package com.example.demo.design.proxy.dynamic;
/**
* 功能描述：
*
* @author Songxianyang
* @date 2022-04-10 13:40
*/
public class LogImpl implements ILog {
@Override
public void pint() {
System.out.println("打印日志");
}
@Override
public void num(int i) {
System.out.println(i);
}
@Override
public int count(int j) {
return j;
}
}
/*******************************************************************************
* Package: com.example.demo.design.proxy.dynamic
* Type: LogProxyFactory
* Date: 2022-04-10 14:13
*
* Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
*
* You may not use this file except in compliance with the License.
*******************************************************************************/
package com.example.demo.design.proxy.dynamic;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
/**
* 功能描述：
* 代理工厂
* @author Songxianyang
* @date 2022-04-10 14:13
*/
public class LogProxyFactory {
/**
* 目标对象
*/
private Object target;
public LogProxyFactory(Object target) {
this.target = target;
}
/**
* 获取目标对象实例
* @return
*/
public Object getTargetExample() {
return Proxy.newProxyInstance(target.getClass().getClassLoader(), target.getClass().getInterfaces(),
new InvocationHandler() {
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
System.out.println("jdk 代理开始");
// 两个参数进行说明 1、目标类 2、参数数组
Object invoke = method.invoke(target, args);
System.out.println("jdk 代理结束");
return invoke;
}
});
}
}
/*******************************************************************************
* Package: com.example.demo.design.proxy.dynamic
* Type: Test
* Date: 2022-04-10 14:21
*
* Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
*
* You may not use this file except in compliance with the License.
*******************************************************************************/
package com.example.demo.design.proxy.dynamic;
/**
* 功能描述：
*
* @author Songxianyang
* @date 2022-04-10 14:21
*/
public class Test {
public static void main(String[] args) {
ILog log = new LogImpl();
LogProxyFactory factory = new LogProxyFactory(log);
// 强制类型转换 要转成 接口的类型 特别奇怪
ILog logn = (ILog) factory.getTargetExample();
//logn.pint();
//logn.num(99);
System.out.println(logn.count(9));
}
}
运行测试
cglib 动态代理
结构
/*******************************************************************************
* Package: com.example.demo.design.proxy.cjlib
* Type: Log
* Date: 2022-04-10 16:56
*
* Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
*
* You may not use this file except in compliance with the License.
*******************************************************************************/
package com.example.demo.design.proxy.cjlib;
/**
* 功能描述：cglib 代理
* 对象代理 并不需要来代理接口
*
*
* @author Songxianyang
* @date 2022-04-10 16:56
*/
public class Log {
public void pint() {
System.out.println("SteveCode 在学习 cglib 动态代理 哈哈");
}
}
/*******************************************************************************
* Package: com.example.demo.design.proxy.cjlib
* Type: ProxyFactory
* Date: 2022-04-10 16:57
*
* Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
*
* You may not use this file except in compliance with the License.
*******************************************************************************/
package com.example.demo.design.proxy.cjlib;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;
import java.lang.reflect.Method;
/**
* 功能描述：
*
* @author Songxianyang
* @date 2022-04-10 16:57
*/
public class ProxyFactory implements MethodInterceptor {
/**
* 目标对象
*/
private Object target;
public ProxyFactory(Object target) {
this.target = target;
}
/**
* 获取代理对象 比较重要
*/
public Object getTargetExample() {
// 创建工具类
Enhancer enhancer = new Enhancer();
// 设置父类
enhancer.setSuperclass(target.getClass());
// 设置回调函数
enhancer.setCallback(this);
// 创建代理对象
return enhancer.create();
}
/**
* 方法增强
* @param o
* @param method 代理对象中的执行方法
* @param args 参数
* @param methodProxy 代理的方法
* @return
* @throws Throwable
*/
@Override
public Object intercept(Object o, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
System.out.println("cglib 代理方法的增强~~~~");
Object invoke = method.invoke(target, args);
System.out.println("cglib 代理方法的提交~~~~");
return invoke;
}
}
/*******************************************************************************
* Package: com.example.demo.design.proxy.cjlib
* Type: Test
* Date: 2022-04-10 17:10
*
* Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
*
* You may not use this file except in compliance with the License.
*******************************************************************************/
package com.example.demo.design.proxy.cjlib;
/**
* 功能描述：
*
* @author Songxianyang
* @date 2022-04-10 17:10
*/
public class Test {
public static void main(String[] args) {
// 目标对象
Log log = new Log();
//获取代理工厂
ProxyFactory factory = new ProxyFactory(log);
// 或缺代理对象
Log log2 = (Log) factory.getTargetExample();
// 执行被代理的方法
log2.pint();
}
}
