Spring AOP with AspectJ XML configuration Example

In spring ,we can define all the pointcut,advice,aspect in the XML file.

AOP advice should be used as below in the XML

1)aop:before: It is applied before the actual business logic method gets executed.

2)aop:after: It is applied after the execution of actual business logic method.

3)aop:after-returning: It is applied after the successful execution of actual business logic method

4)aop:after-throwing: It is applied only if the actual business logic method throws any exception.

5)aop:around: It is applied before and after the execution of actual business logic method.

Before Aspect implementation example

create a spring maven project so that we can manage our dependencies in the pom.xml easily.

Project structure looks like below

AOP_XML_Before


Define the pom.xml file as below to include AspectJ jars and spring jars

  1. <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  2.   xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  3.   <modelVersion>4.0.0</modelVersion>
  4.  
  5.   <groupId>Spring</groupId>
  6.   <artifactId>SpringAOP</artifactId>
  7.   <version>0.0.1-SNAPSHOT</version>
  8.   <packaging>jar</packaging>
  9.  
  10.   <name>SpringAOP</name>
  11.   <url>http://maven.apache.org</url>
  12.  
  13.   <properties>
  14.     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  15.   </properties>
  16.  
  17.   <dependencies>
  18.   <dependency>
  19.     <groupId>org.springframework</groupId>
  20.     <artifactId>spring-core</artifactId>
  21.     <version>4.2.4.RELEASE</version>
  22. </dependency>
  23.   <dependency>
  24.     <groupId>org.springframework</groupId>
  25.     <artifactId>spring-context</artifactId>
  26.     <version>4.2.4.RELEASE</version>
  27. </dependency>
  28. <dependency>
  29.     <groupId>org.aspectj</groupId>
  30.     <artifactId>aspectjrt</artifactId>
  31.     <version>1.7.3</version>
  32. </dependency>
  33.  
  34. <dependency>
  35.     <groupId>aspectj</groupId>
  36.     <artifactId>aspectjweaver</artifactId>
  37.     <version>1.5.4</version>
  38. </dependency>
  39.  
  40.  
  41.     <dependency>
  42.       <groupId>junit</groupId>
  43.       <artifactId>junit</artifactId>
  44.       <version>3.8.1</version>
  45.       <scope>test</scope>
  46.     </dependency>
  47.   </dependencies>
  48. </project>
<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>Spring</groupId>
  <artifactId>SpringAOP</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>SpringAOP</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
  <dependency>
	<groupId>org.springframework</groupId>
	<artifactId>spring-core</artifactId>
	<version>4.2.4.RELEASE</version>
</dependency>
  <dependency>
	<groupId>org.springframework</groupId>
	<artifactId>spring-context</artifactId>
	<version>4.2.4.RELEASE</version>
</dependency>
<dependency>
	<groupId>org.aspectj</groupId>
	<artifactId>aspectjrt</artifactId>
	<version>1.7.3</version>
</dependency>

<dependency>
	<groupId>aspectj</groupId>
	<artifactId>aspectjweaver</artifactId>
	<version>1.5.4</version>
</dependency>


    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>


Let’s create a class which contains a business logic on which we apply Advice.

  1. package com.kb;
  2.  
  3. public class SimpleCalculator {
  4.     public int add(int x,int y){
  5.         return x+y;
  6.     }
  7.    
  8.     public int subtract(int x,int y){
  9.         return x-y;
  10.     }
  11. }
package com.kb;

public class SimpleCalculator {
	public int add(int x,int y){
		return x+y;
	}
	
	public int subtract(int x,int y){
		return x-y;
	}
}

This class has 2 methods where each method performs some business logic,which is addition and subtraction.


Now let’s write the Aspect class as below

  1. package com.kb;
  2. import org.aspectj.lang.JoinPoint;
  3. public class MyBeforeAspect {
  4.     public void myAdvice(JoinPoint jp){
  5.         System.out.println("Before the method "+jp.getSignature().getName()+"started execution");
  6.     }
  7. }
package com.kb;
import org.aspectj.lang.JoinPoint;
public class MyBeforeAspect {
	public void myAdvice(JoinPoint jp){
		System.out.println("Before the method "+jp.getSignature().getName()+"started execution");
	}
}

This Aspect has an advice called myAdvice whose action is to print the log with method name


Now let’s create a beans.xml file which is the spring configuration file where we define our aspect beans and configure the AOP as below

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <beans xmlns="http://www.springframework.org/schema/beans"
  3.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"
  4.     xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
  5.     xsi:schemaLocation="http://www.springframework.org/schema/beans
  6.        http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
  7.        http://www.springframework.org/schema/aop  
  8.         http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
  9.        http://www.springframework.org/schema/context
  10.         http://www.springframework.org/schema/context/spring-context-3.2.xsd">
  11.  
  12.     <aop:aspectj-autoproxy />
  13.  
  14.     <bean id="simpleCalc" class="com.kb.SimpleCalculator"/>
  15.        
  16.  
  17.     <bean id="myBeforeAspect" class="com.kb.MyBeforeAspect" />
  18.  
  19.     <aop:config>
  20.         <aop:aspect id="myAspect" ref="myBeforeAspect">
  21.             <aop:pointcut id="pointCutBefore"
  22.                 expression="execution(* com.kb.SimpleCalculator.*(..))" />
  23.             <aop:before method="myAdvice" pointcut-ref="pointCutBefore" />
  24.         </aop:aspect>
  25.     </aop:config>
  26. </beans>
<?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"
	xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
        http://www.springframework.org/schema/aop   
    	http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
        http://www.springframework.org/schema/context
  		http://www.springframework.org/schema/context/spring-context-3.2.xsd">

	<aop:aspectj-autoproxy />

	<bean id="simpleCalc" class="com.kb.SimpleCalculator"/>
		

	<bean id="myBeforeAspect" class="com.kb.MyBeforeAspect" />

	<aop:config>
		<aop:aspect id="myAspect" ref="myBeforeAspect">
			<aop:pointcut id="pointCutBefore"
				expression="execution(* com.kb.SimpleCalculator.*(..))" />
			<aop:before method="myAdvice" pointcut-ref="pointCutBefore" />
		</aop:aspect>
	</aop:config>
</beans>


We have to add below elements in spring xml file to configure AOP

Need to define AOP namespacelike xmlns:aop=http://www.springframework.org/schema/aop

Need to add < aop:aspectj-autoproxy /> to enable Spring AspectJ support with auto proxy at runtime

Need to configure Aspect classes as any other spring beans

Need to define aop configuration which defines the pointcut and advice mapping using < aop:config> element

expression=”execution(* com.kb.SimpleCalculator.*(..))” defines that advice must be applied to all the methods inside SimpleCalculator class no matter what is its return type and its parameters.


Lets write a class which calls the actual business logic method as below

  1. package com.kb;
  2. import org.springframework.context.ApplicationContext;
  3. import org.springframework.context.support.ClassPathXmlApplicationContext;
  4.  
  5. public class AOPTest {
  6.  
  7.     public static void main(String[] args) {
  8.     ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");  
  9.        SimpleCalculator calculator = (SimpleCalculator) context.getBean("simpleCalc");
  10.       int res1= calculator.add(10, 5);
  11.       System.out.println("Addition result is "+res1);
  12.       int res2= calculator.subtract(10, 5);
  13.       System.out.println("Subtracted result is "+res2);
  14.     }
  15. }
package com.kb;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class AOPTest {

	public static void main(String[] args) {
	ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");  
       SimpleCalculator calculator = (SimpleCalculator) context.getBean("simpleCalc"); 
      int res1= calculator.add(10, 5);
      System.out.println("Addition result is "+res1);
      int res2= calculator.subtract(10, 5);
      System.out.println("Subtracted result is "+res2);
	}
}


Run the above class and see the output as below

Observe the output, before the execution of add and subtract method,our advice code has been executed.

Download this project SpringAOPXML_BeforeAdvice.zip

About the Author

Raj
Founder of javainsimpleway.com
I love Java and open source technologies and very much passionate about software development.
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