- pom中添加两个依赖
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
<version>5.2.5.RELEASE</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.9.5</version>
</dependency>
- 创建UserDAO和UserDaoImpl
public interface UserDao {
public void addUser();
public void deleteUser();
}
@Repository("userDao")
public class UserDaoImpl implements UserDao {
@Override
public void addUser() {
System.out.println("添加用户");
// int i = 1/0;
}
@Override
public void deleteUser() {
System.out.println("删除用户");
}
}
- 定义切面类,编写通知
@Aspect // 定义切面类
@Component // 定义组件
public class MyAspect {
// 定义切入点表达式
@Pointcut("execution(* com.mason.*.*(..))")
public void myPointCut(){}
// 前置通知
@Before("myPointCut()")
public void myBefore(JoinPoint joinPoint){
System.out.print("前置通知。。。");
System.out.print("目标类是:" + joinPoint.getTarget());
System.out.println(", 被植入增强处理的方法是:"+joinPoint.getSignature().getName());
}
// 后置通知
@AfterReturning("myPointCut()")
public void myAfterReturning(JoinPoint joinPoint){
System.out.print("后置通知。。。");
System.out.println("被增强的方法为" + joinPoint.getSignature().getName());
}
// 环绕通知
@Around("myPointCut()")
public Object myAround(ProceedingJoinPoint proceedingJoinPoint) throws Throwable{
System.out.println("环绕开始。。。");
// 执行当前目标方法
Object obj = proceedingJoinPoint.proceed();
System.out.println("环绕结束");
return obj;
}
@AfterThrowing(value = "myPointCut()",throwing = "e")
public void myAfterThrowing(JoinPoint joinPoint, Throwable e){
System.out.println("异常通知" + e.getMessage());
}
@After("myPointCut()")
public void myAfter(){
System.out.println("最终通知。。。");
}
}
- 编写xml配置文件
<?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 https://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">
<context:component-scan base-package="com.mason"/>
<!--启动基于注解的声明式AspectJ支持-->
<aop:aspectj-autoproxy/>
</beans>
- 测试:
public class Test {
public static void main(String[] args) {
ApplicationContext applicationContext =
new ClassPathXmlApplicationContext("spring.xml");
UserDao userDao = (UserDao) applicationContext.getBean("userDao");
userDao.addUser();
}
}
结果:
环绕开始。。。
前置通知。。。目标类是:com.mason.UserDaoImpl@28701274, 被植入增强处理的方法是:addUser
添加用户
环绕结束
最终通知。。。
后置通知。。。被增强的方法为addUser