Spring AOP基於註解的AfterThrowing
[@AfterThrowing](https://github.com/AfterThrowing "@AfterThrowing")
是一種通知類型,可以確保在方法拋出異常時運行一個通知。 以下是[@AfterThrowing](https://github.com/AfterThrowing "@AfterThrowing")
通知的語法:
語法
@AfterThrowing(pointcut="execution(* com.yiibai.Student.*(..))", throwing= "error")
public void afterThrowingAdvice(JoinPoint jp, Throwable error){
System.out.println("Method Signature: " + jp.getSignature());
System.out.println("Exception: "+error);
}
在上面的語法示例中 -
-
[@AfterReturning](https://github.com/AfterReturning "@AfterReturning")
- 如果方法返回成功,則將函數標記爲在切入點覆蓋的方法之前執行的通知。 -
[@Pointcut](https://github.com/Pointcut "@Pointcut")
- 將函數標記爲切入點 -
[@After](https://github.com/After "@After")
- 將函數標記爲在切入點覆蓋的方法之後執行的通知。 -
execution( expression )
- 涵蓋應用通知的方法的表達式。 -
throwing
- 返回的異常名稱。
要了解上面提到的[@AfterThrowing](https://github.com/AfterThrowing "@AfterThrowing")
通知相關的概念,我們寫一個Spring AOP基於註解的應用例子,它將使用基於註解配置實現通知。打開並使用Eclipse IDE,並按照以下步驟創建一個Spring應用程序:
- 更新在Spring AOP應用實例中創建過的
Student
項目。 - 更新
bean
配置並運行應用程序,如下所述。
整個項目的目錄結構如下所示 -
下面是Logging.java
文件的內容。 這實際上是一個Aspect
模塊的樣本,它定義了在各個點被調用的方法。
package com.yiibai;
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.yiibai.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文件的內容:
package com.yiibai;
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
文件的內容:
package com.yiibai;
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文件的內容:
<?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.yiibai.Student">
<property name="name" value="minsu" />
<property name="age" value="24"/>
</bean>
<!-- Definition for logging aspect -->
<bean id="logging" class="com.yiibai.Logging"/>
</beans>
運行項目
完成創建源代碼和配置文件後,運行應用程序。右鍵單擊應用程序中的MainApp.java
,並使用運行方式作爲Java應用程序命令。 如果您的應用程序一切正常,這將打印以下消息:
Exception raised
[afterThrowingAdvice] Method Signature: void com.yiibai.Student.printThrowException()
[afterThrowingAdvice] Exception: java.lang.IllegalArgumentException
Exception in thread "main" java.lang.IllegalArgumentException
at com.yiibai.Student.printThrowException(Student.java:25)
at com.yiibai.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.yiibai.Student$$EnhancerBySpringCGLIB$$bb5ffc0.printThrowException(<generated>)
at com.yiibai.MainApp.main(MainApp.java:16)