[Original]java Web learning Note 106:spring Learn---AOP notifications: pre-notification, post-notification, return notification, exception notification, surround notification

1. Notification Classification:

@before: pre-notification, executed before method execution

@after: Post notification, executed after method execution

@afterrunning: Returns a notification that executes after the method returns the result

@afterthrowing: Exception notification After a method throws an exception

@Around: Surround notification, around method execution

　　about the method signature See 5th

2. Front-facing notification

　　　　

3. Post notification: The results of the target method execution cannot be accessed in the post notification

4. Return notification

5. Exception notification

　　　　　　　　

6. Surround Notifications

　　　　　　

　　　　　　

1  PackageCom.jason.spring.aop.impl;2 3 Importjava.util.Arrays;4 Importjava.util.List;5 6 ImportOrg.aspectj.lang.JoinPoint;7 ImportOrg.aspectj.lang.ProceedingJoinPoint;8 ImportOrg.aspectj.lang.annotation.After;9 Importorg.aspectj.lang.annotation.AfterReturning;Ten Importorg.aspectj.lang.annotation.AfterThrowing; One ImportOrg.aspectj.lang.annotation.Around; A ImportOrg.aspectj.lang.annotation.Aspect; - ImportOrg.aspectj.lang.annotation.Before; - Importorg.springframework.stereotype.Component; the  -  - //declare this class as a slice - //1. The class needs to be placed in the IOC container + @Component - //2. Re-declared as a slice + @Aspect A  Public classLoggingaspect { at      -     //declares that the method is a pre-notification: What classes are executed before the target method starts, and which methods -     //role: @before When the target method is called, and the target method matches the method of the annotation declaration, the AOP framework automatically generates a proxy object for the class where the method is located, and the method to execute the annotation before the target method executes -     //wildcard characters supported -     //@Before ("Execution (public int com.jason.spring.aop.impl.arithmeticcaculatorimpl.* (int, int))" ) -@Before ("Execution (* com.jason.spring.aop.impl.*.* (int, int))") in      Public voidBeforemethod (Joinpoint joinpoint) { -String MethodName =joinpoint.getsignature (). GetName (); tolist<object> args =arrays.aslist (Joinpoint.getargs ()); +System.out.println ("the method" + MethodName + "begins" +args); -     } the      *     /** $      * Panax Notoginseng * @Author: [email protected] - * @Title: Aftermethod the * @Time: December 1, 2016 + * @Description: Code executed after the method executes, regardless of whether the method has an exception A      * the      * @paramJoinpoint +      */ -@After ("Execution (* com.jason.spring.aop.impl.*.* (int, int))") $      Public voidAftermethod (Joinpoint joinpoint) { $String MethodName =joinpoint.getsignature (). GetName (); -list<object> args =arrays.aslist (Joinpoint.getargs ()); -System.out.println ("the method" + MethodName + "End" +args); the     } -     Wuyi     /** the      *  - * @Author: [email protected] Wu * @Title: afterreturning - * @Time: December 1, 2016 About * @Description: Executes the code after the normal end of the method, and put back the notification is a return value that can be accessed to the method $      * -      * @paramJoinpoint -      */ -@AfterReturning (value= "Execution (* com.jason.spring.aop.impl.*.* (..))", returning= "result") A      Public voidafterreturning (joinpoint joinpoint, Object result) { +String MethodName =joinpoint.getsignature (). GetName (); theSystem.out.println ("the method" + MethodName + "End with" +result); -     } $      the     /** the      *  the * @Author: [email protected] the * @Title: afterthrowting - * @Time: December 1, 2016 in * @Description: Executes code when the target method has an exception, can access the exception object, and can specify that the notification code is executed when a specific exception occurs the      * the      * @paramJoinpoint About      * @paramex the      */ the@AfterThrowing (value= "Execution (* com.jason.spring.aop.impl.*.* (..))", throwing= "ex") the      Public voidafterthrowting (Joinpoint joinpoint, Exception ex) { +String MethodName =joinpoint.getsignature (). GetName (); -System.out.println ("the method" + MethodName + "occurs exceptions" +ex); the     }Bayi      the     /** the      *  - * @Author: [email protected] - * @Title: Around the * @Time: December 1, 2016 the * @Description: Surround notifications need to carry Proceedingjoinpoint type parameters the * Surround notification is similar to the whole process of dynamic agents the * Proceedingjoinpoint: Can decide whether to execute the target method - * Surround notification must have a return value, which is the return value of the target method the      *     the      * @paramProceedingjoinpoint the      */94@Around ("Execution (* com.jason.spring.aop.impl.*.* (..))") the      PublicObject Around (proceedingjoinpoint proceedingjoinpoint) { the          theObject result =NULL;98String MethodName =proceedingjoinpoint.getsignature (). GetName (); About          -         //Execute target Method101         Try {102             //front-facing notifications103System.out.println ("the method" + MethodName + "begin with" +arrays.aslist (Proceedingjoinpoint.getargs ()));104              theresult =proceedingjoinpoint.proceed ();106             107             //Post Notification108System.out.println ("the method" + MethodName + "End with" +result);109              the}Catch(Throwable e) {111             //Exception Notification theSystem.out.println ("The method occurs exception:" +e);113             Throw Newruntimeexception (); the         } the             //Post Notification the             117System.out.println ("the method" + MethodName + "End with" +result);118         119         returnresult; -         121     }122     123     124}

　　　　

[Original]java Web learning Note 106:spring Learn---AOP notifications: pre-notification, post-notification, return notification, exception notification, surround notification