[FIXED] Spring AOP - Determine whether method was invoked by @Scheduled

Issue

I have a runtime annotation @MyAnnotation, and I would like to write an Aspect that determines whether the test() method below was called by:

• Spring's @Scheduled framework
• normal method invocation

@SpringBootApplication
public class MyApplication {

    public static void main(String[] args) {
        SpringApplication.run(MyApplication.class, args);
    }

    @Scheduled(cron = "*/1 * * * * *") // scheduled to invoke every second
    @MyAnnotation
    public void test() {
        // business logic
    }
}

aspect code (pointcut + advice)

    @Around(value="@annotation(myAnnotation)")
    public Object featureToggle(ProceedingJoinPoint joinPoint, MyAnnotation myAnnotation) throws Throwable {
        Boolean isInvoked = // TODO - is invoked by @Scheduled or not
    }

Solution

Inspecting stack traces is always ugly, but of course you can do it:

package de.scrum_master.spring.q65397019;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

@Retention(RetentionPolicy.RUNTIME)
public @interface MyAnnotation {}

package de.scrum_master.spring.q65397019;

import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

@Component
public class MyComponent {
  @Scheduled(fixedRate = 1000)
//  @Async
  @MyAnnotation
  public void doSomething() {}
}

package de.scrum_master.spring.q65397019;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.annotation.EnableScheduling;

@SpringBootApplication
@Configuration
@EnableScheduling
@EnableAsync
public class DemoApplication {
  public static void main(String[] args) throws InterruptedException {
    try (ConfigurableApplicationContext appContext = SpringApplication.run(DemoApplication.class, args)) {
      doStuff(appContext);
    }
  }

  private static void doStuff(ConfigurableApplicationContext appContext) throws InterruptedException {
    MyComponent myComponent = appContext.getBean(MyComponent.class);
    myComponent.doSomething();
    Thread.sleep(1000);
    myComponent.doSomething();
  }
}

package de.scrum_master.spring.q65397019;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;

import java.util.Arrays;

@Aspect
@Component
public class MyAspect {
  @Around("@annotation(myAnnotation)")
  public Object advice2(ProceedingJoinPoint joinPoint, MyAnnotation myAnnotation) throws Throwable {
    if (
      Arrays.stream(new Exception().getStackTrace())
        .map(StackTraceElement::toString)
        .anyMatch(string -> string.contains("scheduling.support.ScheduledMethodRunnable.run("))
    )
      System.out.println(joinPoint + " -> scheduled");
    else
      System.out.println(joinPoint + " -> normal");
    return joinPoint.proceed();
  }
}

This will print something like:

(...)
2020-12-22 10:00:59.372  INFO 1620 --- [           main] o.s.s.c.ThreadPoolTaskScheduler          : Initializing ExecutorService 'taskScheduler'
execution(void de.scrum_master.spring.q65397019.MyComponent.doSomething()) -> scheduled
2020-12-22 10:00:59.456  INFO 1620 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
2020-12-22 10:00:59.456  INFO 1620 --- [           main] d.s.spring.q65397019.DemoApplication     : Started DemoApplication in 6.534 seconds (JVM running for 8.329)
execution(void de.scrum_master.spring.q65397019.MyComponent.doSomething()) -> normal
execution(void de.scrum_master.spring.q65397019.MyComponent.doSomething()) -> scheduled
execution(void de.scrum_master.spring.q65397019.MyComponent.doSomething()) -> normal
2020-12-22 10:01:00.475  INFO 1620 --- [           main] o.s.s.c.ThreadPoolTaskScheduler          : Shutting down ExecutorService 'taskScheduler'
2020-12-22 10:01:00.477  INFO 1620 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Shutting down ExecutorService 'applicationTaskExecutor'
(...)

On Java 9+ you could use the stack walking API which would be more efficient than creating full stack traces from exception instances or querying them from the currently running thread.

Caveat: If you also annotate your scheduled method with @Async, then this will not work anymore because then the asynchronously running method does not have a stack trace in which you could identify that it was triggered by a ScheduledMethodRunnable or an application class.

Answered By - kriegaex