Shutdown of Executor service in Spring Boot when Tomcat shuts down

Question

I have configured an executor service in Spring Boot as follows:

@Configuration
@PropertySource({ "classpath:executor.properties" })
public class ExecutorServiceConfig {

    @Value("${"executor.thread.count"}")
    private int executorThreadCount;

    @Bean("executorThreadPool")
    public ThreadPoolExecutor cachedThreadPool() {
        return new ThreadPoolExecutor(executorThreadCount, executorThreadCount, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>());
    }
}

The app is deployed on a independent Tomcat instance. When the Tomcat server shuts down, I have found that there are still tasks in the queue that are not completed. As a result, I will lose data. Is there a way for me to call awaitTermination on this executor service so that it will get a chance to finish what is in the queue? Thanks!

Answer 1

Annotate with @PreDestroy annotation. Then perform the shutdown of the executo service from there.

@Configuration
class ExecutorServiceConfiguration {

    @Value("${"executor.thread.count"}")
    private int executorThreadCount;


     public static class MyExecutorService {
           private ThreadPoolExecutor executor;

           public MyExecutorService(ThreadPoolExecutor executor) {
               this.executor = executor;
           }
           @PreDestroy()
           public destroy() {
                  // destroy executor
           }
     }

    @Bean("executorThreadPool")
    public ThreadPoolExecutor cachedThreadPool() {
        return new ThreadPoolExecutor(executorThreadCount, executorThreadCount, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>());
    }

    @Bean
    public MyExecutorService configureDestroyableBean(ThreadPoolExecutor cachedThreadPool) 
    {
      return new MyExecutorService(cachedThreadPool);
    }

}