Spring AOP + AspectJ Annotation Example

原文地址：http://www.mkyong.com/spring3/spring-aop-aspectj-annotation-example/

In this tutorial, we show you how to integrate AspectJ annotation with Spring AOP framework. In simple, Spring AOP + AspectJ allow you to intercept method easily.

Common AspectJ annotations :

@Before – Run before the method execution
@After – Run after the method returned a result
@AfterReturning – Run after the method returned a result, intercept the returned result as well.
@AfterThrowing – Run after the method throws an exception
@Around – Run around the method execution, combine all
three advices above.

1. Directory Structure

See directory structure of this example.

2. Project Dependencies

To enable AspectJ, you need aspectjrt.jar, aspectjweaver.jar and spring-aop.jar. See following Maven

pom.xml

file.

AspectJ supported since Spring 2.0
This example is using Spring 3, but the AspectJ features are supported since Spring 2.0.

File : pom.xml

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<project ...>



<properties>

<spring.version>3.0.5.RELEASE</spring.version>

</properties>



<dependencies>



<dependency>

<groupId>org.springframework</groupId>

<artifactId>spring-core</artifactId>

<version>${spring.version}</version>

</dependency>



<dependency>

<groupId>org.springframework</groupId>

<artifactId>spring-context</artifactId>

<version>${spring.version}</version>

</dependency>



<!-- Spring AOP + AspectJ -->

<dependency>

<groupId>org.springframework</groupId>

<artifactId>spring-aop</artifactId>

<version>${spring.version}</version>

</dependency>



<dependency>

<groupId>org.aspectj</groupId>

<artifactId>aspectjrt</artifactId>

<version>1.6.11</version>

</dependency>



<dependency>

<groupId>org.aspectj</groupId>

<artifactId>aspectjweaver</artifactId>

<version>1.6.11</version>

</dependency>



</dependencies>

</project>

3. Spring Beans

Normal bean, with few methods, later intercept it via AspectJ annotation.

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package com.mkyong.customer.bo;



public interface CustomerBo {



void addCustomer();



String addCustomerReturnValue();



void addCustomerThrowException() throws Exception;



void addCustomerAround(String name);

}

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package com.mkyong.customer.bo.impl;



import com.mkyong.customer.bo.CustomerBo;



public class CustomerBoImpl implements CustomerBo {



public void addCustomer(){

System.out.println("addCustomer() is running ");

}



public String addCustomerReturnValue(){

System.out.println("addCustomerReturnValue() is running ");

return "abc";

}



public void addCustomerThrowException() throws Exception {

System.out.println("addCustomerThrowException() is running ");

throw new Exception("Generic Error");

}



public void addCustomerAround(String name){

System.out.println("addCustomerAround() is running, args : " + name);

}

}

4. Enable AspectJ

In Spring configuration file, put “

<aop:aspectj-autoproxy />

“,
and define your Aspect (interceptor) and normal bean.

File : Spring-Customer.xml

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<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 />



<bean id="customerBo" class="com.mkyong.customer.bo.impl.CustomerBoImpl" />



<!-- Aspect -->

<bean id="logAspect" class="com.mkyong.aspect.LoggingAspect" />



</beans>

4. AspectJ @Before

In below example, the

logBefore()

method will be executed
before the execution of customerBo interface,

addCustomer()

method.
Note

AspectJ “pointcuts” is used to declare which method is going to intercept, and you should refer to this Spring
AOP pointcuts guide for full list of supported pointcuts expressions.

File : LoggingAspect.java

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package com.mkyong.aspect;



import org.aspectj.lang.JoinPoint;

import org.aspectj.lang.annotation.Aspect;

import org.aspectj.lang.annotation.Before;



@Aspect

public class LoggingAspect {



@Before("execution(* com.mkyong.customer.bo.CustomerBo.addCustomer(..))")

public void logBefore(JoinPoint joinPoint) {



System.out.println("logBefore() is running!");

System.out.println("hijacked : " + joinPoint.getSignature().getName());

System.out.println("******");

}



}

Run it(applicationContext.xml)

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public static void main(String args[]){

ApplicationContext appContext = new ClassPathXmlApplicationContext("applicationContext.xml");

CustomerBo customer = (CustomerBo) appContext.getBean("customerBo");

customer.addCustomer();

}

5. AspectJ @After

In below example, the

logAfter()

method will be executed
after the execution of customerBo interface,

addCustomer()

method.

File : LoggingAspect.java
.

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package com.mkyong.aspect;



import org.aspectj.lang.JoinPoint;

import org.aspectj.lang.annotation.Aspect;

import org.aspectj.lang.annotation.After;



@Aspect

public class LoggingAspect {



@After("execution(* com.mkyong.customer.bo.CustomerBo.addCustomer(..))")

public void logAfter(JoinPoint joinPoint) {



System.out.println("logAfter() is running!");

System.out.println("hijacked : " + joinPoint.getSignature().getName());

System.out.println("******");



}



}

Run it

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CustomerBo customer = (CustomerBo) appContext.getBean("customerBo");

customer.addCustomer();

6. AspectJ @AfterReturning

In below example, the

logAfterReturning()

method will be
executed after the execution of customerBo interface,

addCustomerReturnValue()

method.
In addition, you can intercept the returned value with the “returning” attribute.

To intercept returned value, the value of the “returning” attribute (result) need to be same with the method parameter (result).

File : LoggingAspect.java

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package com.mkyong.aspect;



import org.aspectj.lang.JoinPoint;

import org.aspectj.lang.annotation.Aspect;

import org.aspectj.lang.annotation.AfterReturning;



@Aspect

public class LoggingAspect {



@AfterReturning(

pointcut = "execution(* com.mkyong.customer.bo.CustomerBo.addCustomerReturnValue(..))",

returning= "result")

public void logAfterReturning(JoinPoint joinPoint, Object result) {



System.out.println("logAfterReturning() is running!");

System.out.println("hijacked : " + joinPoint.getSignature().getName());

System.out.println("Method returned value is : " + result);

System.out.println("******");



}



}

Run it

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CustomerBo customer = (CustomerBo) appContext.getBean("customerBo");

customer.addCustomerReturnValue();

7. AspectJ @AfterReturning

In below example, the

logAfterThrowing()

method will be executed
if the customerBo interface,

addCustomerThrowException()

method
is throwing an exception.

File : LoggingAspect.java

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package com.mkyong.aspect;



import org.aspectj.lang.JoinPoint;

import org.aspectj.lang.annotation.Aspect;

import org.aspectj.lang.annotation.AfterThrowing;



@Aspect

public class LoggingAspect {



@AfterThrowing(

pointcut = "execution(* com.mkyong.customer.bo.CustomerBo.addCustomerThrowException(..))",

throwing= "error")

public void logAfterThrowing(JoinPoint joinPoint, Throwable error) {



System.out.println("logAfterThrowing() is running!");

System.out.println("hijacked : " + joinPoint.getSignature().getName());

System.out.println("Exception : " + error);

System.out.println("******");



}

}

Run it

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CustomerBo customer = (CustomerBo) appContext.getBean("customerBo");

customer.addCustomerThrowException();

Output

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addCustomerThrowException() is running

logAfterThrowing() is running!

hijacked : addCustomerThrowException

Exception : java.lang.Exception: Generic Error

******

Exception in thread "main" java.lang.Exception: Generic Error

//...

8. AspectJ @Around

In below example, the

logAround()

method will be executed
before the customerBo interface,

addCustomerAround()

method,
and you have to define the “

joinPoint.proceed();

” to control
when should the interceptor return the control to the original

addCustomerAround()

method.
File : LoggingAspect.java

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package com.mkyong.aspect;



import org.aspectj.lang.ProceedingJoinPoint;

import org.aspectj.lang.annotation.Aspect;

import org.aspectj.lang.annotation.Around;



@Aspect

public class LoggingAspect {



@Around("execution(* com.mkyong.customer.bo.CustomerBo.addCustomerAround(..))")

public void logAround(ProceedingJoinPoint joinPoint) throws Throwable {



System.out.println("logAround() is running!");

System.out.println("hijacked method : " + joinPoint.getSignature().getName());

System.out.println("hijacked arguments : " + Arrays.toString(joinPoint.getArgs()));



System.out.println("Around before is running!");

joinPoint.proceed(); //continue on the intercepted method

System.out.println("Around after is running!");



System.out.println("******");



}



}

Run it

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CustomerBo customer = (CustomerBo) appContext.getBean("customerBo");

customer.addCustomerAround("mkyong");

Output

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logAround() is running!

hijacked method : addCustomerAround

hijacked arguments : [mkyong]

Around before is running!

addCustomerAround() is running, args : mkyong

Around after is running!

******