Spring 学习(八)：AOP异常通知和环绕通知

一、配置异常通知的步骤(AspectJ方式)

1. 只有在切点报异常才能触发异常通知，否则无效
2. 在Spirng 中只有 AspectJ 方式提供可异常通知的方法
3. 实现步骤
   1. 新建类，在类写任意名称的方法

      package com.zhang.advice;
      
      public class MyThrowAdvice {
      
      	public void myexception(Exception e) {
      		System.out.println("执行异常通知，异常信息："+e.getMessage());
      	}
      }
      

   2. 在 spring 配置文件中配置
      2.1 < aop:aspect/>的 ref 属性表示：方法在哪个类中
      2.2 < aop:xxx/> 表示什么通知
      2.3 method: 当触发这个通知时，调用哪个方法
      2.4 在异常通知里，throwing表示异常对象名，必须和通知中方法参数名相同(不用写异常对象)

      <?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:tx="http://www.springframework.org/schema/tx"
          xmlns:context="http://www.springframework.org/schema/context"
          xsi:schemaLocation="http://www.springframework.org/schema/beans
              http://www.springframework.org/schema/beans/spring-beans.xsd
              http://www.springframework.org/schema/tx
              http://www.springframework.org/schema/tx/spring-tx.xsd
              http://www.springframework.org/schema/aop
              http://www.springframework.org/schema/aop/spring-aop.xsd
              http://www.springframework.org/schema/context
              http://www.springframework.org/schema/context/spring-context.xsd"
              default-autowire="byName">
              
              <bean id="mythrow" class="com.zhang.advice.MyThrowAdvice"></bean>
              
              <aop:config>
          		<aop:aspect ref="mythrow">
          			<aop:pointcut expression="execution(* com.zhang.pojo.Demo.demo2(..))" id="mypoint"/>
          			<aop:after-throwing method="myexception" pointcut-ref="mypoint" throwing="e"/>
          		</aop:aspect>
          	</aop:config>
              
             <bean id="demo" class="com.zhang.pojo.Demo"></bean>
              
      </beans>
      

二、配置异常通知的步骤(Schema-based方式)

1. 新建一个类实现 ThrowsAdvice接口
   1.1 必须自己写方法，且必须叫 afterThrowing
   1.2 有两种参数方式，必须是1个或者4个
   1.3 异常类型要与切点报的异常类型一致

   package com.zhang.advice;
   import java.lang.reflect.Method;
   
   import org.springframework.aop.ThrowsAdvice;
   
   public class MyThrowAdvice implements ThrowsAdvice{
   
   //	public void afterThrowing(Method arg0,Object[] arg1,Object arg2,Exception e) {
   //		System.out.println("执行异常通知");
   //	}
   	
   	public void afterThrowing(Exception e) {
   		System.out.println("执行异常通知");
   	}
   }
   
   

2. 配置 spring 配置文件

   <?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:tx="http://www.springframework.org/schema/tx"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans.xsd
           http://www.springframework.org/schema/tx
           http://www.springframework.org/schema/tx/spring-tx.xsd
           http://www.springframework.org/schema/aop
           http://www.springframework.org/schema/aop/spring-aop.xsd
           http://www.springframework.org/schema/context
           http://www.springframework.org/schema/context/spring-context.xsd"
           default-autowire="byName">
           
           <!-- 注入通知类 -->
           <bean id="myBefore" class="com.zhang.advice.MyBefore"></bean>
           <bean id="myAfter" class="com.zhang.advice.MyAfter"></bean>
           <bean id="mythrow" class="com.zhang.advice.MyThrowAdvice"></bean>
           
           <aop:config>
           	<aop:pointcut expression="execution(* com.zhang.pojo.Demo.demo2(..))" id="mypoint"/>
           	<aop:advisor advice-ref="mythrow" pointcut-ref="mypoint" />
       	</aop:config>
           
           
          <bean id="demo" class="com.zhang.pojo.Demo"></bean>
   	
   </beans>	
   

三、配置环绕通知的步骤(Schema-based方式)

把前置通知和后置通知都写到一个通知中，组成了环绕

1. 新建一个类实现 MethodInterceptor接口

   package com.zhang.advice;
   import org.aopalliance.intercept.MethodInterceptor;
   import org.aopalliance.intercept.MethodInvocation;
   
   public class MyArround implements MethodInterceptor{
   
   	@Override
   	public Object invoke(MethodInvocation arg0) throws Throwable {
   		
   		System.out.println("环绕--前置");
   		Object result = arg0.proceed();//放行，执行切点程序
   		System.out.println("环绕--后置");
   		return result;
   	}
   
   }
   

2. spring 配置文件

   <?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:tx="http://www.springframework.org/schema/tx"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans.xsd
           http://www.springframework.org/schema/tx
           http://www.springframework.org/schema/tx/spring-tx.xsd
           http://www.springframework.org/schema/aop
           http://www.springframework.org/schema/aop/spring-aop.xsd
           http://www.springframework.org/schema/context
           http://www.springframework.org/schema/context/spring-context.xsd"
           default-autowire="byName">
           
           <!-- 注入通知类 -->
           <bean id="myBefore" class="com.zhang.advice.MyBefore"></bean>
           <bean id="myAfter" class="com.zhang.advice.MyAfter"></bean>
           <bean id="mythrow" class="com.zhang.advice.MyThrowAdvice"></bean>
           <bean id="myArround" class="com.zhang.advice.MyArround"></bean>
           
           <aop:config>
           	<aop:pointcut expression="execution(* com.zhang.pojo.Demo.demo2(..))" id="mypoint"/>
           	<aop:advisor advice-ref="myArround" pointcut-ref="mypoint" />
       	</aop:config>
           
           
          <bean id="demo" class="com.zhang.pojo.Demo"></bean>
           
   </beans>
   
   

本文地址：https://blog.csdn.net/qq_43478581/article/details/110825979