package com.jeremy.aop.example;import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.springframework.stereotype.Component;
/** 使用AOP的步骤* 1声明一个切面，切面必须是在IOC容器中，所以必须添加@component注解，而且还说明是一个切面，所以还要添加@Aspect注解* 2定义通知：通知有五种，分别是前置通知、后置通知、返回通知、异常通知、环绕通知，根据业务需求定义所需的通知* 3在通知里说明通知时由那个类的那个方法执行* 4在Spring的配置文件自动扫描<context:component-scan>和配置AspectJ* 配置AspectJ是当我们调用一个目标方法时，而这个目标方法跟我注解声明的方法相匹配的时候，那么AOP框架应该自动的为那个方法所在的那个类生成一个代理对象，* 在我目标方法执行之前先来执行切面的对应的方法*/@Aspect
@Component
public class LoggingAspect {@Before("execution(* com.jeremy.aop.example.ArithmeticCalculator.*(..))")private void beforeMethod() {System.out.println("the Method begins........");}@After("execution(* com.jeremy.aop.example.ArithmeticCalculator.*(..))")private void afterMethod() {// TODO Auto-generated method stubSystem.out.println("The Method after ................");}@AfterReturning(value="execution(* com.jeremy.aop.example.ArithmeticCalculator.*(..))",returning="result")public void AfterReturning(JoinPoint joinPoint,Object result){System.out.println("The Method after ................"+result);}@AfterThrowing(value="execution(* com.jeremy.aop.example.ArithmeticCalculator.*(..))",throwing="e")public void AfterThrowing(JoinPoint joinPoint,Exception e){System.out.println("The Method afterThrowing  ................"+e.getMessage().toString());}@Around(value="execution(* com.jeremy.aop.example.ArithmeticCalculator.*(..))")public Object aroundTest(ProceedingJoinPoint pjp){String methodName=pjp.getSignature().getName();Object object=null;try {// 前置通知System.out.println("The Method "+methodName+"before  ................");object=pjp.proceed();//返回通知System.out.println(object);} catch (Throwable e) {// TODO Auto-generated catch block//异常通知System.out.println(e.getMessage().toString());}System.out.println("The Method "+methodName+"    after  ................");return object;}
}

/*** 定义一个方法, 用于声明切入点表达式. 一般地, 该方法中再不需要添入其他的代码. * 使用 @Pointcut 来声明切入点表达式. * 后面的其他通知直接使用方法名来引用当前的切入点表达式. */@Pointcut("execution(public int com.atguigu.spring.aop.ArithmeticCalculator.*(..))")public void declareJointPointExpression(){}/*** 在 com.atguigu.spring.aop.ArithmeticCalculator 接口的每一个实现类的每一个方法开始之前执行一段代码*/@Before("declareJointPointExpression()")public void beforeMethod(JoinPoint joinPoint){String methodName = joinPoint.getSignature().getName();Object [] args = joinPoint.getArgs();System.out.println("The method " + methodName + " begins with " + Arrays.asList(args));}