CODEWITHSUNDEEP
javaspringspring-mvcannotations
Mars_rider
Mars_rider

Reputation: 19

Around Annotation in Spring

I've the following programs. The around method is getting called but why not the main method? As far as i know around method gets executed before or after the method execution. Here around method getting called but why it's not printing the main method i.e.,getEmploy();.

@Configuration
public class App extends Thread{

    public static void main(String[] args) {

        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
        context.scan("com.inno.aop");
        context.refresh();
        EmployManager emp = (EmployManager) context.getBean("employManager");
        emp.getEmploy();
        context.close();
    }

}


@Service
public class EmployManager {

    public void getEmploy() {
        System.out.println("Here is your employ" );
    }
    public void getEmp() {
        System.out.println("Here is your emp" );
    }
}


@Aspect
@Component
@EnableAspectJAutoProxy(proxyTargetClass = true)
public class EmployAspect {

     @Around("execution(* com.inno.aop.EmployManager.*(..))")
     public void logAround(JoinPoint joinPoint) {
         System.out.println("Around method getting called");
    }

}



Output:

Around method getting called

Upvotes: 0

Views: 21318

Answers (3)

R.G
R.G

Reputation: 7131

From the documentation

Around advice: Advice that surrounds a join point such as a method invocation. This is the most powerful kind of advice. Around advice can perform custom behavior before and after the method invocation. It is also responsible for choosing whether to proceed to the join point or to shortcut the advised method execution by returning its own return value or throwing an exception.

We need to use ProceedingJoinPoint with @Around advice

org.aspectj.lang.ProceedingJoinPoint

Around advice is declared by using the @Around annotation. The first parameter of the advice method must be of type ProceedingJoinPoint. Within the body of the advice, calling proceed() on the ProceedingJoinPoint causes the underlying method to execute. The proceed method can also pass in an Object[]. The values in the array are used as the arguments to the method execution when it proceeds.

The code should be

 @Around("execution(* com.inno.aop.EmployManager.*(..))")
 public void logAround(ProceedingJoinPoint joinPoint) throws Throwable {
     System.out.println("Around method getting called");
     joinPoint.proceed();
 }

Upvotes: 3

Satish
Satish

Reputation: 1065

Within the method annotated with @Around, one need to call joinPoint.proceed(), then only the intercepted method will be called. Also,

  1. make sure to extract the method arguments and pass that to joinPoint.proceed(Object[] args).
  2. Return the object returned by joinPoint.proceed, from your logAround() method, incase intercepted method is not a void.
@Aspect
@Component
@EnableAspectJAutoProxy(proxyTargetClass = true)
public class EmployAspect {

    @Around("execution(* com.inno.aop.EmployManager.*(..))")
    public void logAround(JoinPoint joinPoint) {
        System.out.println("Around method getting called");
        joinPoint.proceed();
    }
}

Upvotes: 0

Mark Bramnik
Mark Bramnik

Reputation: 42531

Around aspect intercepts the call and you can decide whether to proceed to the real class or not. In this code snipped you just call System.out.println and do not run the real class's method...

You should call:

@Around(...)
public void logAround(JoinPoint joinPoint) {
   jointPoint.proceed();  // + handle exceptions if required
}

Upvotes: 0

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