@AfterThrowing
是一种通知类型,可以确保在方法抛出异常时运行一个通知。 以下是@AfterThrowing
通知的语法:
语法
@AfterThrowing(pointcut="execution(* com.zyiz.Student.*(..))", throwing= "error") public void afterThrowingAdvice(JoinPoint jp, Throwable error){ System.out.println("Method Signature: " + jp.getSignature()); System.out.println("Exception: "+error); }
在上面的语法示例中 -
@AfterReturning
- 如果方法返回成功,则将函数标记为在切入点覆盖的方法之前执行的通知。@Pointcut
- 将函数标记为切入点@After
- 将函数标记为在切入点覆盖的方法之后执行的通知。execution( expression )
- 涵盖应用通知的方法的表达式。throwing
- 返回的异常名称。要了解上面提到的@AfterThrowing
通知相关的概念,我们写一个Spring AOP基于注解的应用例子,它将使用基于注解配置实现通知。打开并使用Eclipse IDE,并按照以下步骤创建一个Spring应用程序:
Student
项目。bean
配置并运行应用程序,如下所述。整个项目的目录结构如下所示 -
下面是Logging.java
文件的内容。 这实际上是一个Aspect
模块的样本,它定义了在各个点被调用的方法。
package com.zyiz; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.JoinPoint; import org.aspectj.lang.annotation.AfterThrowing; @Aspect public class Logging { /** * This is the method which I would like to execute * after a selected method execution throws exception. */ @AfterThrowing(pointcut="execution(* com.zyiz.Student.*(..))", throwing= "error") public void afterThrowingAdvice(JoinPoint jp, Throwable error){ System.out.println("[afterThrowingAdvice] Method Signature: " + jp.getSignature()); System.out.println("[afterThrowingAdvice] Exception: "+error); } }
以下是Student.java文件的内容:
package com.zyiz; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class MainApp { public static void main(String[] args) { ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml"); Student student = (Student) context.getBean("student"); student.printThrowException(); } }
以下是MainApp.java
文件的内容:
package com.zyiz; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class MainApp { public static void main(String[] args) { ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml"); Student student = (Student) context.getBean("student"); student.printThrowException(); } }
以下是配置文件Beans.xml文件的内容:
<?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" 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 "> <aop:aspectj-autoproxy/> <!-- Definition for student bean --> <bean id="student" class="com.zyiz.Student"> <property name="name" value="minsu" /> <property name="age" value="24"/> </bean> <!-- Definition for logging aspect --> <bean id="logging" class="com.zyiz.Logging"/> </beans>
完成创建源代码和配置文件后,运行应用程序。右键单击应用程序中的MainApp.java
,并使用运行方式作为Java应用程序命令。 如果您的应用程序一切正常,这将打印以下消息:
Exception raised [afterThrowingAdvice] Method Signature: void com.zyiz.Student.printThrowException() [afterThrowingAdvice] Exception: java.lang.IllegalArgumentException Exception in thread "main" java.lang.IllegalArgumentException at com.zyiz.Student.printThrowException(Student.java:25) at com.zyiz.Student$$FastClassBySpringCGLIB$$e9280b4b.invoke(<generated>) at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:717) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) at org.springframework.aop.aspectj.AspectJAfterThrowingAdvice.invoke(AspectJAfterThrowingAdvice.java:58) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:653) at com.zyiz.Student$$EnhancerBySpringCGLIB$$bb5ffc0.printThrowException(<generated>) at com.zyiz.MainApp.main(MainApp.java:16)