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
<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.
package com.mkyong.customer.bo;
public interface CustomerBo {
void addCustomer();
String addCustomerReturnValue();
void addCustomerThrowException() throws Exception;
void addCustomerAround(String name);
}
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
<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.
File : LoggingAspect.java
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
CustomerBo customer = (CustomerBo) appContext.getBean("customerBo");
customer.addCustomer();
Output
logBefore() is running!
hijacked : addCustomer
******
addCustomer() is running
5. AspectJ @After
In below example, the logAfter()
method will be executed after the execution of customerBo
interface, addCustomer()
method.
File : LoggingAspect.java
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
CustomerBo customer = (CustomerBo) appContext.getBean("customerBo");
customer.addCustomer();
Output
addCustomer() is running
logAfter() is running!
hijacked : 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
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
CustomerBo customer = (CustomerBo) appContext.getBean("customerBo");
customer.addCustomerReturnValue();
Output
addCustomerReturnValue() is running
logAfterReturning() is running!
hijacked : addCustomerReturnValue
Method returned value is : abc
******
7. AspectJ @AfterThrowing
In below example, the logAfterThrowing()
method will be executed if the customerBo
interface, addCustomerThrowException()
method is throwing an exception.
File : LoggingAspect.java
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
CustomerBo customer = (CustomerBo) appContext.getBean("customerBo");
customer.addCustomerThrowException();
Output
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
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
CustomerBo customer = (CustomerBo) appContext.getBean("customerBo");
customer.addCustomerAround("mkyong");
Output
logAround() is running!
hijacked method : addCustomerAround
hijacked arguments : [mkyong]
Around before is running!
addCustomerAround() is running, args : mkyong
Around after is running!
******
Conclusion
It’s always recommended to apply the least power AsjectJ annotation.