Spring AOP的五种通知方式代码实例

<?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-3.0.xsd
              http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
              http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
  <!--配置自动扫描的包-->
  <context:component-scan base-package="com.atguigu.spring.aop"></context:component-scan>

  <!--配置自动为匹配aspectJ 注解的Java类生成代理对象-->
  <aop:aspectj-autoproxy></aop:aspectj-autoproxy>

</beans>

//接口
public interface ArithmeticCalculator {
  int add(int i, int j);
  int sub(int i, int j);
  int mul(int i, int j);
  int div(int i, int j);
}

package com.atguigu.spring.aop;

import org.springframework.stereotype.Component;

/**
 * @Author 谢军帅
 * @Date2019/12/6 21:23
 * @Description
 */

//实现类
@Component("arithmeticCalculator")
public class ArithmeticCalculatorImpl implements ArithmeticCalculator {
  @Override
  public int add(int i, int j) {
    int relust = i+j;
    return relust;
  }

  @Override
  public int sub(int i, int j) {
    int relust = i-j;
    return relust;
  }

  @Override
  public int mul(int i, int j) {
    int relust = i*j;
    return relust;
  }

  @Override
  public int div(int i, int j) {
    int relust = i/j;
    return relust;
  }
}

package com.atguigu.spring.aop;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.*;
import org.springframework.stereotype.Component;

import java.util.Arrays;

/**
 * @Author 谢军帅
 * @Date2019/12/11 11:17
 * @Description
 */
@Component
@Aspect
public class LoggingAspect {
  /**
   * 在每一个接口的实现类的每一个方法开始之前执行一段代码
   */

  @Before("execution(public int com.atguigu.spring.aop.ArithmeticCalculator.* (..))")
  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));
  }

  @After("execution(public int com.atguigu.spring.aop.ArithmeticCalculator.* (..))")
  public void afterMethod(JoinPoint joinPoint){
    String methodName = joinPoint.getSignature().getName();

    System.out.println("The method "+methodName +" end......");
  }


  /**
   * 返回通知
   * 在方法正常结束后执行的代码
   * 返回通知是可以访问方法的返回值的！
   * @param joinPoint*/
   
  @AfterReturning(value = "execution(public int com.atguigu.spring.aop.ArithmeticCalculator.* (..))",
          returning = "result")
  public void afterReturning(JoinPoint joinPoint,Object result){
    String methodName = joinPoint.getSignature().getName();
    System.out.println("The method "+methodName +" end......result:"+result);
  }


  /**
   * 在目标方法出现异常时会执行的代码
   * 可以访问到异常对象，且可以指定在出现特定异常时在执行通知代码
   * @param joinPoint
   * @param ex*/
   
  @AfterThrowing(value = "execution(public int com.atguigu.spring.aop.ArithmeticCalculator.* (..))", throwing = "ex")
  public void afterThrowing(JoinPoint joinPoint, Exception ex){
    String methodName = joinPoint.getSignature().getName();
    System.out.println("The method "+methodName +"occurs exception :" +ex);
  }

  /**
   * 环绕通知需要携带 ProceedingJoinPoint 类型的参数
   * 环绕通知类似于动态代理的全过程：ProceedingJoinPoint 类型的参数可以决定是否执行目标方法。
   * 且环绕通知必须有返回值，返回值即为目标方法的返回值
   * @param proceedingJoinPoint
   */
  /*@Around("execution(public int com.atguigu.spring.aop.ArithmeticCalculator.* (..))")
  public Object aroundMethod(ProceedingJoinPoint proceedingJoinPoint){

    Object result = null;
    String methodName = proceedingJoinPoint.getSignature().getName();

    try {
      //前置通知
      System.out.println("The method "+methodName+" begins with "+Arrays.asList(proceedingJoinPoint.getArgs()));
      //执行目标方法
      result = proceedingJoinPoint.proceed();

      //返回通知
      System.out.println("The method ends with "+result);
    } catch (Throwable e) {
      //异常通知
      System.out.println("The method occurs exception:"+e);

      throw new RuntimeException(e);
    }

    //后置通知
    System.out.println("The method "+methodName+" ends........");

    return result;
  }*/
}

public class Test_aop {
  public static void main(String[] args) {
    ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
    ArithmeticCalculator arithmeticCalculator = (ArithmeticCalculator) context.getBean("arithmeticCalculator");
    System.out.println(arithmeticCalculator.getClass().getName());
    int result = arithmeticCalculator.add(1,2);
    System.out.println("result:"+result);
    result = arithmeticCalculator.div(200,0);
    System.out.println("result:"+result);
  }
}