spring的核心思想（二）：AOP-后置通知&异常通知

后置通知：通知类实现 AfterReturnAdvice接口

异常通知：通知类实现 ThrowsAdvice接口

<!-- 管理StudentService组件对象-->
<bean class="com.pcf.service.StudentServiceImpl" id="studentService"></bean>
<!-- 注册通知-->
<bean class="com.pcf.advices.MyAfterAdvice" id="myAfterAdvice"></bean>
<aop:config>
    <aop:pointcut id="afterPc" expression="within(com.pcf.service.StudentServiceImpl)"></aop:pointcut>
    <aop:advisor advice-ref="myAfterAdvice" pointcut-ref="afterPc"></aop:advisor>
</aop:config>

package com.pcf.advices;

import org.springframework.aop.AfterReturningAdvice;
import org.springframework.aop.ThrowsAdvice;

import java.lang.reflect.Method;

/**
 * @author yourname
 * @date 2021/4/14 23:05
 */
public class MyAfterAdvice implements AfterReturningAdvice, ThrowsAdvice {
    @Override
    public void afterReturning(Object returnValue, Method method, Object[] args, Object target) throws Throwable {
        System.out.println("===============进入后置通知=================");
        System.out.println("执行的方法：" + method.getName());
        System.out.println("方法的参数：" + args[0]);
    }

    // 处理异常时通知
    public void afterThrowing(Method method, Object[] args, Object target, Exception ex){
        System.out.println("处理异常时通知");
        System.out.println("ex.getMessage()" + ex.getMessage());
    }
}