Let’s create a simple spring application and add logging aspect to be invoked every joint point in the service class in the application. This example is also available with XML configuration in the application Spring AOP After-returning Advice Example.
@AfterReturning annotation is Aspectj annotation, not Spring AOP annotation, so also we have to add Aspectj maven dependency with Spring AOP in this example. Let’s see our LoggingAspect class with after advice annotation.
/** * */ package com.doj.aopapp.aspect; import org.aspectj.lang.JoinPoint; import org.aspectj.lang.annotation.AfterReturning; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Pointcut; import org.springframework.stereotype.Component; /** * @author Dinesh.Rajput * */ @Aspect @Component public class LoggingAspect { /** * Declaring After Returning advice * @param jp * @throws Throwable */ //@AfterReturning("execution(* com.doj.aopapp.service.*.*(..))") // After Returning advice with pointcut expression directly @AfterReturning("logForAllMethods()") //After Returning advice with name pointcut that declared as name logForAllMethods() public void afterReturningAdviceForAllMethods(JoinPoint jp) throws Throwable { System.out.println("****LoggingAspect.afterReturningAdviceForAllMethods() " + jp.getSignature().getName()); } /** * Declaring After Returning advice for all transfer methods whose taking three arguments of any type * of all classes in the package com.doj.aopapp.service * @param jp * @throws Throwable */ @AfterReturning("execution(* com.doj.aopapp.service.*.transfer(*,*,*))") public void afterReturningAdviceForTransferMethods(JoinPoint jp) throws Throwable { System.out.println("****LoggingAspect.afterReturningAdviceForTransferMethods() " + jp.getSignature().getName()); } /** * Declaring named pointcut */ @Pointcut("execution(* com.doj.aopapp.service.*.*(..))") public void logForAllMethods(){} }
#1. We have declared for after returning advice, it is valid for all public methods with any number arguments of any type and any return type, for all classes in the com.doj.aopapp.service package.
@AfterReturning("execution(* com.doj.aopapp.service.*.*(..))")
#2. We have declared for after returning advice, it is valid for all public methods whose name is transfer() with taking three arguments of any type and any return type, for all classes in the com.doj.aopapp.service package.
@AfterReturning("execution(* com.doj.aopapp.service.*.transfer(*,*,*))")
#3. Named Pointcut
/** * Declaring named pointcut */ @Pointcut("execution(* com.doj.aopapp.service.*.*(..))") public void logForAllMethods(){} //After Returning advice with name pointcut that declared as name logForAllMethods() @AfterReturning("logForAllMethods()") public void afterReturningAdviceForAllMethods(JoinPoint jp) throws Throwable { System.out.println("****LoggingAspect.afterReturningAdviceForAllMethods() " + jp.getSignature().getName()); }
As mention above, we could also declare named pointcut for removing duplicity of complex and repetitive pointcut expressions in the application.
Now let’s see complete example of Spring AOP aspectj @AfterReturning annotation.
<properties> <spring.version>4.3.7.RELEASE</spring.version> <aspectj.version>1.8.9</aspectj.version> </properties> <dependencies> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjrt</artifactId> <version>${aspectj.version}</version> </dependency> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>${aspectj.version}</version> </dependency> </dependencies>
AppConfig.java
/** * */ package com.doj.aopapp.config; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.EnableAspectJAutoProxy; /** * @author Dinesh.Rajput * */ @Configuration @EnableAspectJAutoProxy @ComponentScan(basePackages={"com.doj.aopapp.aspect", "com.doj.aopapp.service"}) public class AppConfig { }
Spring AOP provides an annotation to enable @AspectJ support in the application. By default spring framework doesn’t create any proxy for any advice, so we have to enable by using @EnableAspectJAutoProxy annotation.
@Configuration @EnableAspectJAutoProxy public class AppConfig { }
<aop:aspectj-autoproxy/> namespace is equivalent to @EnableAspectJAutoProxy annotation to enable @AspectJ support in the application in XML configuration. Let’s see how to use this namespace <aop:aspectj-autoproxy/>.
<!-- Enable @AspectJ annotation support --> <aop:aspectj-autoproxy/>
TransferService.java
/** * */ package com.doj.aopapp.service; /** * @author Dinesh.Rajput * */ public interface TransferService { void transfer(String accountA, String accountB, Long amount); Double checkBalance(String account); Long withdrawal(String account, Long amount); void diposite(String account, Long amount); }
TransferServiceImpl.java
/** * */ package com.doj.aopapp.service; import org.springframework.stereotype.Service; /** * @author Dinesh.Rajput * */ @Service public class TransferServiceImpl implements TransferService { @Override public void transfer(String accountA, String accountB, Long amount) { System.out.println(amount+" Amount has been tranfered from "+accountA+" to "+accountB); } @Override public Double checkBalance(String account) { System.out.println("Available balance: 50000"); return new Double(50000); } @Override public Long withdrawal(String account, Long amount) { System.out.println("Withdrawal amount: " +amount); return amount; } @Override public void diposite(String account, Long amount) { System.out.println(amount+" Amount has been diposited to "+account); } }
Aspect class:
LoggingAspect.java as given above in this tutorial.
Test Class for Spring AspectJ Configuration and Execution
Let’s execute following test class and analyse the output on the console.
/** * */ package com.doj.aopapp.test; import org.springframework.context.ConfigurableApplicationContext; import org.springframework.context.annotation.AnnotationConfigApplicationContext; import com.doj.aopapp.config.AppConfig; import com.doj.aopapp.service.TransferService; /** * @author Dinesh.Rajput * */ public class Main { /** * @param args */ public static void main(String[] args) { ConfigurableApplicationContext applicationContext = new AnnotationConfigApplicationContext(AppConfig.class); TransferService transferService = applicationContext.getBean(TransferService.class); transferService.transfer("accountA", "accountB", 50000l); transferService.checkBalance("accountA"); transferService.diposite("accountA", 50000l); transferService.withdrawal("accountB", 40000l); applicationContext.close(); } }
As output of above console logs, every log messages has been executed just after target method execution.
Strategy Design Patterns We can easily create a strategy design pattern using lambda. To implement…
Decorator Pattern A decorator pattern allows a user to add new functionality to an existing…
Delegating pattern In software engineering, the delegation pattern is an object-oriented design pattern that allows…
Technology has emerged a lot in the last decade, and now we have artificial intelligence;…
Managing a database is becoming increasingly complex now due to the vast amount of data…
Overview In this article, we will explore Spring Scheduler how we could use it by…