Start thread at springboot application

Question

I want to execute a java class (which contains a java thread I want to execute) after spring boot starts. My initial code:

@SpringBootApplication
public clas         


        

Answer 1

Don't mess around with threads yourself. Spring (and also plain Java) has a nice abstraction for that.

First create a bean of the type TaskExecutor in your configuration

@Bean
public TaskExecutor taskExecutor() {
    return new SimpleAsyncTaskExecutor(); // Or use another one of your liking
}

Then create a CommandLineRunner (although an ApplicationListener<ContextRefreshedEvent> would also work) to schedule your task.

@Bean
public CommandLineRunner schedulingRunner(TaskExecutor executor) {
    return new CommandLineRunner() {
        public void run(String... args) throws Exception {
            executor.execute(new SimularProfesor());
        }
    }
}

You could of course make also your own class managed by spring.

Advantage of this is that Spring will also cleanup the threads for you and you don't have to think about it yourself. I used a CommandLineRunner here because that will execute after all beans have bean initialized.

Answer 2

• Main Class SpringBoot

  @SpringBootApplication
  @EnableAsync
  @Controller
  public class ...
  
  

• Example Class Controler

  import javax.annotation.PostConstruct;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.context.ApplicationContext;
  import org.springframework.core.task.TaskExecutor;
  import org.springframework.stereotype.Component;
  
  @Component
  public class ExecutorBase {
  
      private static final Logger log = LoggerFactory.getLogger(ExecutorBase.class);
  
      @Autowired
      private TaskExecutor taskExecutor;
      @Autowired
      private ApplicationContext applicationContext;
  
      private Boolean debug = true;
  
      @PostConstruct
      public void atStartup() {
          ClasseTaskRunn classeTaskRunn = applicationContext.getBean(ClasseTaskRunn.class);
          taskExecutor.execute(classeTaskRunn );
          if (debug) {
              log.warn("###### Startup ok");
          }
      }
  }
  
  

• Example Class Task Runnable

  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.context.annotation.Scope;
  import org.springframework.stereotype.Component;
  
  @Component
  @Scope("application")
  public class ClasseTaskRunn implements Runnable {
  
      private static final Logger log = LoggerFactory.getLogger(ClasseTaskRunn.class);
  
      @Autowired
      ClasseDAO classeDAO;
  
      @Override
      public void run() {
          longBackgorund();
      }
  
      protected void longBackgorund() {
          while (test) {
              if (debug) {
                  log.warn("###### DEBUG: " ... );
              }
  
              try {
                  Thread.sleep(10000);
              } catch (InterruptedException e) {
                  e.printStackTrace();
              }
          }
      }
  }