Spring AOP demo 和获取被CGLIB代理的对象

本文分为两部分：1）给出Spring AOP的一个例子（会使用CGLIB代理）；2）给出获取被CGLIB代理的原始对象。

1、Spring AOP Demo

这部分参考了博文（http://www.voidcn.com/blog/daguanjia11/article/p-4628090.html）

1.1添加maven依赖

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>4.0.5.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>4.0.5.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.0.5.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>4.0.5.RELEASE</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.8.1</version>
</dependency>

1.2添加测试类

public class SpringAopTest {

public static class Car {
public void go() {
System.out.println("go go go!");
}
}

public static class CarLogger {

public void beforeRun() {
System.out.println("car is going to run");
}

public void afterRun() {
System.out.println("car is running");
}
}

public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("spring-aop-test.xml");
Car car = (Car) context.getBean("car");
System.out.println(car.getClass());
car.go();
}
}

1.3添加spring配置文件

放置在classpath的根目录下，额，放在resources目录下也就行了。

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd">

<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd" >
<bean id="car" class="com.SpringAopTest.Car"/>
<bean id="logger" class="com.SpringAopTest.CarLogger" />
<aop:config>
<aop:aspect ref="logger">
<aop:pointcut expression="execution(* com.SpringAopTest.Car.go(..))" id="go"/>

<aop:before pointcut-ref="go" method="beforeRun" />
<aop:after pointcut-ref="go" method="afterRun" />
</aop:aspect>
</aop:config>
</beans>

</beans>

1.4运行main函数

得到如下结果：

car is going to run
go go go!
car is running

呐，你看go go go!前后都有后添加的动作吧。

2、获取被CGLIB代理的对象

这部分内容参考了博文（https://www.geek-share.com/detail/2634200485.html）

我们先通过debug看一下被代理对象被藏在哪里了

好，看完了，我们来写一下代码，如下：

import java.lang.reflect.Field;

import org.springframework.aop.framework.AdvisedSupport;
import org.springframework.aop.support.AopUtils;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
* Created by qm on 17/2/15.
*/
public class SpringAopTest {

public static class Car {
public void go() {
System.out.println("go go go!");
}
}

public static class CarLogger {

public void beforeRun() {
System.out.println("car is going to run");
}

public void afterRun() {
System.out.println("car is running");
}
}

public static Object getTarget(Object beanInstance) {
if (!AopUtils.isAopProxy(beanInstance)) {
return beanInstance;
} else if (AopUtils.isCglibProxy(beanInstance)) {
try {
Field h = beanInstance.getClass().getDeclaredField("CGLIB$CALLBACK_0");
h.setAccessible(true);
Object dynamicAdvisedInterceptor = h.get(beanInstance);

Field advised = dynamicAdvisedInterceptor.getClass().getDeclaredField("advised");
advised.setAccessible(true);

Object target = ((AdvisedSupport) advised.get(dynamicAdvisedInterceptor)).getTargetSource().getTarget();
return target;
} catch (NoSuchFieldException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}

}
return null;

}

public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("spring-aop-test.xml");
Car car = (Car) context.getBean("car");
Object target = getTarget(car);
System.out.println(target == car);
System.out.println(car.getClass());
System.out.println(target.getClass());
car.go();
}
}