Spring AOP Advices - After returning advice example - xml based configuration

In Spring, aspect-oriented programming (AOP) is a programming paradigm that aims to increase modularity by allowing the separation of cross-cutting concerns. AOP forms a basis for aspect-oriented software development.

In this page you will see an example for Spring AOP - After returning advice. Spring After returning advice will be executed after the every method execution.

pom.xml file gives all required dependencies:

<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>cglib</groupId>            <artifactId>cglib</artifactId>            <version>3.1</version>        </dependency>    </dependencies></project>

My business logic service class: It has only one method runMyBusinessLogic() contains the business logic, we want to run advice method after every execution of this method.

package com.java2novice.bean;public class MyBusinessService {    public void runMyBusinessLogic(){        System.out.println("**************************");        System.out.println("Running business logic...");        System.out.println("**************************");    }}

Now create “After Returning Advice”. Create a class which implements AfterReturningAdvice interface. It will execute after the method every execution.

package com.java2novice.aop;import java.lang.reflect.Method;import org.springframework.aop.AfterReturningAdvice;public class RunAfterExecution implements AfterReturningAdvice{    @Override    public void afterReturning(Object retVal, Method methodArg, Object[] args,                                         Object target) throws Throwable {        System.out.println("Inside RunAfterExecution.afterReturning() method...");        System.out.println("Running after advice...");    }}

Here is the xml based configuration file. Add bean entry for RunAfterExecution class (after return advice class). Also create a proxy for MyBusinessService class. In this proxy configuration, you should add two properties called ‘target’ and ‘interceptorNames‘. ‘target’ defines in which bean you want to introduce advice. ‘interceptorNames’ defines that which advice class you want to introduce to the said target.

<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"    xsi:schemaLocation="http://www.springframework.org/schema/beans    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd    http://www.springframework.org/schema/context     http://www.springframework.org/schema/context/spring-context-3.0.xsd">    <bean id="busService" class="com.java2novice.bean.MyBusinessService" />    <bean id="afterAdv" class="com.java2novice.aop.RunAfterExecution" />    <bean id="busServiceProxy" class="org.springframework.aop.framework.ProxyFactoryBean" >        <property name="target" ref="busService" />        <property name="interceptorNames">            <list>                <value>afterAdv</value>            </list>        </property>    </bean></beans>

Here is the final demo class: Note that we are calling proxy bean object, not the business service bean directly.

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("busServiceProxy");        busServ.runMyBusinessLogic();    }}

Output:

************************************Running business logic...************************************Inside RunAfterExecution.afterReturning() method...Running after advice...