Spring AOP - AspectJ - @AfterReturning example

Last few pages talked about spring advices (before advice, after return advice, around advice and pointcut examples). In this page you will get an idea about how to integrate AspectJ annotations with Spring AOP framework. Using spring AOP and AspectJ, you can easily intercept methods.

AspectJ comes with below annotations:

1) @Before
2) @After
3) @AfterReturning
4) @AfterThrowing
5) @Around

In this page we will see an example for @AfterReturning annotation. @AfterReturning annotation intercepts method after calling it. You have seen similar behavior with @After annotation in the previous example, but @AfterReturning will intercept the return value as well.

pom.xml file gives all required dependencies: Add dependencies for spring-aop jar, aspectjrt jar and aspectjweaver jar file.

<project xmlns="http://maven.apache.org/POM/4.0.0"    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0     http://maven.apache.org/xsd/maven-4.0.0.xsd">    <modelVersion>4.0.0</modelVersion>    <groupId>SpringJavaBasedConfig</groupId>    <artifactId>SpringJavaBasedConfig</artifactId>    <version>0.0.1-SNAPSHOT</version>    <properties>        <spring.version>3.2.0.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>        <dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-aop</artifactId>            <version>${spring.version}</version>        </dependency>        <dependency>            <groupId>org.aspectj</groupId>            <artifactId>aspectjrt</artifactId>            <version>1.8.0</version>        </dependency>        <dependency>            <groupId>org.aspectj</groupId>            <artifactId>aspectjweaver</artifactId>            <version>1.8.0</version>        </dependency>        <dependency>            <groupId>cglib</groupId>            <artifactId>cglib</artifactId>            <version>3.1</version>        </dependency>    </dependencies></project>

My business logic service class:

package com.java2novice.bean;public class MyBusinessService {    public String runMyBusinessLogic(){        System.out.println("************************************");        System.out.println("Running business logic...");        System.out.println("************************************");        return "Successfully executed my business logic";    }    public void testThrowException() {        throw new NullPointerException();    }}

Here is the Aspect class example. The after() method will be executed after calling the method. Note here you have specified “returning” attribute as part of your annotation. Make sure that the annotation returning attribute value should be same as method input parameter.

package com.java2novice.aop;import org.aspectj.lang.JoinPoint;import org.aspectj.lang.annotation.AfterReturning;import org.aspectj.lang.annotation.Aspect;@Aspectpublic class RunAfterExecution {    @AfterReturning(    pointcut="execution(* com.java2novice.bean.MyBusinessService.runMyBusinessLogic(..))",     returning="returnValue")    public void runAfter(JoinPoint joinPoint, String returnValue) throws Throwable {        System.out.println("Inside RunAfterExecution.afterReturning() method...");        System.out.println("inserted after : " + joinPoint.getSignature().getName());        System.out.println("Method returned value is : " + returnValue);    }}

Here is the xml based configuration file. By adding “<aop:aspectj-autoproxy />” tag, you can enable AspectJ with in your application. Add bean definitions for your normal bean and your Aspect.

<beans xmlns="http://www.springframework.org/schema/beans"    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"    xmlns:context="http://www.springframework.org/schema/context"    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="busService" class="com.java2novice.bean.MyBusinessService" />    <bean id="beforeAspectBean" class="com.java2novice.aop.RunAfterExecution" /> </beans>

Here is the final demo class:

package com.java2novice.test;import org.springframework.context.ConfigurableApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import com.java2novice.bean.MyBusinessService;public class SpringDemo {    public static void main(String a[]){        String confFile = "applicationContext.xml";        ConfigurableApplicationContext context =                                 new ClassPathXmlApplicationContext(confFile);        MyBusinessService busServ = (MyBusinessService) context.getBean("busService");        busServ.runMyBusinessLogic();    }}

Output:

************************************Running business logic...************************************Inside RunAfterExecution.afterReturning() method...inserted after : runMyBusinessLogicMethod returned value is : Successfully executed business logic