1.IUserService.java
package com.zy.aop07;
import java.util.List;
public interface IUserService {
/**
* 获取所有的用户对象列表
* @return
*/
List<Object> getAllUser();
/**
* 保存用户
* @param user
* @return
*/
boolean saveUser(Object user);
/**
* 根据用户uid删除该uid对应的用户信息
* @param uid
* @return
*/
boolean deleteUser(int uid);
/**
* 更新指定用户信息
* @param obj
* @return
*/
boolean updateUser(Object obj);
void getUserByUid();
}
2.UserServiceImpl.java
package com.zy.aop07;
import org.springframework.stereotype.Component;
import java.util.ArrayList;
import java.util.List;
@Component("us")
public class UserServiceImpl implements IUserService {
@Override
public List<Object> getAllUser() {
System.out.println("--------getAllUser----------");
return new ArrayList<>();
}
@Override
public boolean saveUser(Object user) {
System.out.println("--------saveUser----------");
return true;
}
@Override
public boolean deleteUser(int uid) {
System.out.println("--------deleteUser----------");
return false;
}
@Override
public boolean updateUser(Object obj) {
System.out.println("--------updateUser----------");
return true;
}
@Override
public void getUserByUid() {
System.out.println("--------getUserByUid----------");
System.out.println(1 / 0);
String str = null;
System.out.println(str.length());
}
}
3.MyAspect.java
package com.zy.aop07;
/**
* 自定义切面类，分别有前置方法和后置方法
*/
public class MyAspect {
public void before(){
System.out.println("this is my aspect before");
}
public void after(){
System.out.println("this is my aspect after");
}
}
4.beans.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<!--<bean id="us" class="com.zy.aop07.UserServiceImpl" />-->
<!--
context:component-scan上下文的组件扫描
base-package指定要扫描的包为com.zy.aop07
-->
<context:component-scan base-package="com.zy.aop07" />
<!--
指定BeanPostProcessor的Factory hook，让每个bean对象初始化是自动回调该对象中的回调方法
-->
<bean class="com.zy.aop07.MyBeanPostProcessor" />
</beans>
5.MyBeanPostProcessor.java
package com.zy.aop07;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
/**
* 配置了包扫描之后，该类会初始化两个对象EventListenerMethodProcessor和DefaultEventListenerFactory，再外加我们自己的组件对象
*
* 所以会发现有三个before打印
*
* 我还专门加了一个UserServiceImpl2，你会发现将有四个before的打印（注意看看该类上的Component注解是否启用）
*
*/
public class MyBeanPostProcessor implements BeanPostProcessor {
@Override
public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
System.out.println("this is before " + bean);
return bean;
}
@Override
public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
System.out.println("this is after");
return Proxy.newProxyInstance(MyBeanPostProcessor.class.getClassLoader(), bean.getClass().getInterfaces(), new InvocationHandler() {
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
MyAspect ma = new MyAspect();
ma.before();
Object obj = method.invoke(bean, args);
ma.after();
return obj;
}
});
}
}
6.TestAOP07.java
package com.zy.aop07;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class TestAOP07 {
@Test
public void testAOP07(){
ApplicationContext ac = new ClassPathXmlApplicationContext("com/zy/aop07/beans.xml");
IUserService us = ac.getBean("us", IUserService.class);
us.deleteUser(1);
us.updateUser("zhangsan");
us.saveUser("lisi");
us.getAllUser();
us.getUserByUid();
}
}
