Spring阶段性学习总结（十 一）Aspect实现各种通知

package SpringAopImp;

public interface Calculator {
    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 SpringAopImp;


import org.springframework.stereotype.Component;

@Component
public class CalculatorImp  implements Calculator {
       
    @Override
    public int add(int i, int j) {
        int result=i+j;
        System.out.println("Method is Running");
        return result;
    }

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

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

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

package SpringAopImp;

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

import java.util.Arrays;
import java.util.List;

//把这个类声明为一个切面:1、把该类放入到IOC容器中

@Component
@Aspect
public class LoggingAspect {

    //前置通知在目标方法开始前执行
    @Before("execution(public int SpringAopImp.CalculatorImp.add(int ,int))")
    public void beforeMethod(JoinPoint joinPoint) {
        String methodName = joinPoint.getSignature().getName();
        List<Object> args = Arrays.asList(joinPoint.getArgs());
        System.out.println("The Method:" + methodName + " beginWith:" + args);
    }

    //后置通知，在目标方法开始后执行，无论方法是否发生异常
    @After("execution(public int SpringAopImp.CalculatorImp.add(int ,int))")
    public void afterMethod(JoinPoint joinPoint) {
        String methodName = joinPoint.getSignature().getName();
        System.out.println("The Method:" + methodName + " ends");
    }

    //返回通知，在目标方法正常结束后执行的代码，返回通知是可以返回方法的返回值的
    @AfterReturning(value = "execution(public int SpringAopImp.CalculatorImp.add(int ,int))", returning = "result")
    public void afterReturning(JoinPoint joinPoint, Object result) {
        String methodName = joinPoint.getSignature().getName();
        System.out.println("The Method:" + methodName + " endsWith:" + result);
    }

    /*
     * 异常通知，在目标方法出现异常的时候，调用代码
     * 可以访问异常对象；且可以指定在出现特定异常时在执行通知代码
     * */
    @AfterThrowing(value = "execution(public int SpringAopImp.CalculatorImp.add(int ,int))", throwing = "ex")
    public void afterThrowing(JoinPoint joinPoint, Exception ex) {
        String methodName = joinPoint.getSignature().getName();
        System.out.println("The Method :" + methodName + "has Exception: " + ex);
    }

}

<?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:context="http://www.springframework.org/schema/context"
       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/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">

        <context:component-scan base-package="SpringAopImp"></context:component-scan>
        <!--使 AspectJ注解起作用  :自动为匹配的类生成代理对象-->
      <aop:aspectj-autoproxy></aop:aspectj-autoproxy>
</beans>

package SpringAopImp;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Main {
    public static void main(String[] args) {
        ClassPathXmlApplicationContext ctx= new ClassPathXmlApplicationContext("SpringAopImp/SpringAopImp.xml");
        Calculator calculatorImp = (Calculator) ctx.getBean("calculatorImp");
        System.out.println(calculatorImp.getClass().getName());
        System.out.println(calculatorImp.add(1,3));
    }
}