Spring AOP AspectJ Annotation Configuration Example

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AspectJ libraries provides the facility to declare aspect, pointcut etc with the help of annotations. Let us discuss the commonly used AspectJ annotations first.

Declaring an aspect:

The @Aspect annotation is used to declare a class as an aspect.

@Aspect
public class AspectModule {
 
}

Declaring a pointcut:

The @Pointcut annotation is used to declare a pointcut. The expression parameter represents the expression used for matching the join point.

@Pointcut("execution(expression)")
private void businessService() {
	//Block of code.
}

Declaring advices:

The @{ADVICE-NAME} annotations is used to declare an advice.

Spring AOP AspectJ Annotation Configuration Advice Example:

BusinessLogic.java

/**
 * This class will be used as a bean class.
 * @author w3schools
 */
public class BusinessLogic {
	public void implementBusinessLogic(){
	  System.out.println("Business logic executed.");
	}
 
	public String returnValue(){
	  System.out.println("Return value executed.");
	  return "w3schools.com";
	}
 
	public void throwException(){
	  System.out.println("Business logic throw exception.");
	  throw new ArithmeticException("Arithmetic exception occure.");
	}
}

AdviceTest.java

import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
 
@Aspect
public class AdviceTest {  
 
@Pointcut("execution(* com.w3schools.business.*.*(..))")
private void selectAll(){
 
}
 
@Before("selectAll()")
public void beforeAdvice(){
     System.out.println("Before advice executed.");
}
 
@After("selectAll()")
public void afterAdvice(){
    System.out.println("After advice executed.");
}
 
@AfterReturning(pointcut = "selectAll()", returning="retVal")
public void afterReturningAdvice(Object retVal){
    System.out.println("After returning advice executed.");
    System.out.println("Returning value: " + retVal);
}
 
@AfterThrowing(pointcut = "selectAll()", throwing = "ex")
public void afterThrowingAdvice(ArithmeticException ex){
  System.out.println("Throwing advice executed.");
  System.out.println("Exception: " + ex.getMessage());   
}
}

applicationContext.xml

<?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"
    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:config>
      <aop:aspect id="log" ref="adviceTest">
         <aop:pointcut id="selectAll" 
         expression="execution(* com.w3schools.business.*.*(..))"/>
         <aop:before pointcut-ref="selectAll" method="beforeAdvice"/>
         <aop:after pointcut-ref="selectAll" method="afterAdvice"/>
         <aop:after-returning pointcut-ref="selectAll" 
                              returning="retVal"
                              method="afterReturningAdvice"/>
         <aop:after-throwing pointcut-ref="selectAll" 
                             throwing="ex"
                             method="afterThrowingAdvice"/>
      </aop:aspect>
   </aop:config>
 
   <bean id="businessLogic" 
    class="com.w3schools.business.BusinessLogic"/>
   <bean id="adviceTest" 
    class="com.w3schools.business.AdviceTest"/>
 
</beans>

Test.java

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
 
public class Test {
 public static void main(String[] args) {
  //Get ApplicationContext using spring configuration file.
  ApplicationContext context = 
    new ClassPathXmlApplicationContext("applicationContext.xml");
 
  //Get BusinessLogic bean object from ApplicationContext instance. 
  BusinessLogic businessLogic = 
    (BusinessLogic) context.getBean("businessLogic");
 
  //Call implementBusinessLogic method of BusinessLogic bean.
  businessLogic.implementBusinessLogic();
  System.out.println("------------------------------------");
  businessLogic.returnValue();
  System.out.println("------------------------------------");
  businessLogic.throwException();
 } 
}

Output:

Before advice executed.
Business logic executed.
After advice executed.
After returning advice executed.
Returning value: null
-----------------------------------------
Before advice executed.
Return value executed.
After advice executed.
After returning advice executed.
Returning value: w3schools.com
-----------------------------------------
Before advice executed.
Business logic throw exception.
After advice executed.
Throwing advice executed.
Exception: Arithmetic exception occure.
Exception in thread "main" java.lang.ArithmeticException: Arithmetic exception occure.
	at com.w3schools.business.BusinessLogic.throwException(BusinessLogic.java:19)
	at com.w3schools.business.BusinessLogic$$FastClassByCGLIB$$19ab96db.invoke(<generated>)
	at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:191)
	at org.springframework.aop.framework.Cglib2AopProxy$CglibMethodInvocation.invokeJoinpoint(Cglib2AopProxy.java:692)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
	at org.springframework.aop.aspectj.AspectJAfterAdvice.invoke(AspectJAfterAdvice.java:42)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
	at org.springframework.aop.framework.adapter.AfterReturningAdviceInterceptor.invoke(AfterReturningAdviceInterceptor.java:50)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
	at org.springframework.aop.aspectj.AspectJAfterThrowingAdvice.invoke(AspectJAfterThrowingAdvice.java:55)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
	at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:50)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
	at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:89)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
	at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:625)
	at com.w3schools.business.BusinessLogic$$EnhancerByCGLIB$$4299115d.throwException(<generated>)
	at com.w3schools.business.Test.main(Test.java:20)

 
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