spring之aop实例
面向切面编程(也叫面向方面编程):Aspect Oriented Programming(AOP),是软件开发中的一个热点,也是 Spring
框架中的一个重要内容。利用 AOP 可以对业务逻辑的各个部分进行隔离,从而使得业务逻辑各部分之间的耦合度
降低,提高程序的可重用性,同时提高了开发的效率。
主要的功能是:日志记录,性能统计,安全控制,事务处理,异常处理等等。
spring之aop实例分析
1,前置通知;2,后置通知;3,环绕通知;4,返回通知;5,异常通知
StudentService接口
package com.java1234.service;
public interface StudentService {
public void addStudent(String name);
}
StudentServiceImpl实现类
package com.java1234.service.impl;
import com.java1234.service.StudentService;
public class StudentServiceImpl implements StudentService{
@Override
public void addStudent(String name) {
// System.out.println("开始添加学生"+name);
System.out.println("添加学生"+name);
System.out.println(1/0);
// System.out.println("完成学生"+name+"的添加");
}
}
测试类
package com.java1234.test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.java1234.service.StudentService;
public class T {
public static void main(String[] args) {
ApplicationContext ac=new ClassPathXmlApplicationContext("beans.xml");
StudentService studentService=(StudentService)ac.getBean("studentService");
studentService.addStudent("张三");
}
}
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"
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">
//定义切面bean(studentServiceAspect)
<bean id="studentServiceAspect" class="com.java1234.advice.StudentServiceAspect"></bean>
<bean id="studentService" class="com.java1234.service.impl.StudentServiceImpl"></bean>
//切面配置
<aop:config>
<aop:aspect id="studentServiceAspect" ref="studentServiceAspect">//切面bean(studentServiceAspect)
//切点,*.*(..)第二个*代表任意的方法名,小括号中..代表方法可以任意参数
<aop:pointcut expression="execution(* com.java1234.service.*.*(..))" id="businessService"/>
//前置通知;后置通知;环绕通知;返回通知;异常通知
<aop:before method="doBefore" pointcut-ref="businessService"/>
<aop:after method="doAfter" pointcut-ref="businessService"/>
<aop:around method="doAround" pointcut-ref="businessService"/>
<aop:after-returning method="doAfterReturning" pointcut-ref="businessService"/>
<aop:after-throwing method="doAfterThrowing" pointcut-ref="businessService" throwing="ex"/>
</aop:aspect>
</aop:config>
</beans>
切面类
package com.java1234.advice;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
public class StudentServiceAspect {
public void doBefore(JoinPoint jp){
System.out.println("类名:"+jp.getTarget().getClass().getName());
System.out.println("方法名:"+jp.getSignature().getName());
System.out.println("开始添加学生:"+jp.getArgs()[0]);
}
public void doAfter(JoinPoint jp){
System.out.println("类名:"+jp.getTarget().getClass().getName());
System.out.println("方法名:"+jp.getSignature().getName());
System.out.println("学生添加完成:"+jp.getArgs()[0]);
}
public Object doAround(ProceedingJoinPoint pjp) throws Throwable{
System.out.println("添加学生前");
Object retVal=pjp.proceed();
System.out.println(retVal);
System.out.println("添加学生后");
return retVal;
}
public void doAfterReturning(JoinPoint jp){
System.out.println("返回通知");
}
public void doAfterThrowing(JoinPoint jp,Throwable ex){
System.out.println("异常通知");
System.out.println("异常信息:"+ex.getMessage());
}
}
运行结果: