Spring boot run code after application Startup

In this tutorial, we will see how to run code immediately after spring boot application start. There are cases where we need to run tasks after application started.

• upgrade step to update DB data
• update config
• clear cache in redis
• Make API call to load external config into DB
• load config from DB to System.properties

In the above cases , we need to configured some logic which should be executed after spring boot applications start. The below are multiple ways to achieve this.

1. EventListener annotation:

The below is code for EventListener and this is recommended approach:

import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.context.event.EventListener;
import org.springframework.stereotype.Component;

@Component
public class StartupLogicRunner {
 
   @Autowired
   private UpgradeService upgradeService;

    @EventListener
    public void handleContextRefresh(ContextRefreshedEvent event) {
        // Your logic here
        System.out.println("Application started successfully!");

        upgradeService.handleDBUpdate_v.10();


    }
}

2. Using ApplicationListener

The below is example code with ApplicationListener:

import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.stereotype.Component;

@Component
public class SpringBootUpgradeStep implements ApplicationListener<ContextRefreshedEvent> {
   

  @Autowired
  private UpgradeService upgradeService;

   @Override
    public void onApplicationEvent(ContextRefreshedEvent event) {
        // Your logic here
        System.out.println("Application started successfully!");

      upgradeService.handleDBUpdate_v.10();


    }
}

3. Using PostConstruct Annotation:

The below is sample code using PostConstruct :

import javax.annotation.PostConstruct;
import org.springframework.stereotype.Component;

@Component
public class StartupLogicRunner {
  
     
   @Autowired
   private UpgradeService upgradeService;

    @PostConstruct
    public void init() {
        // Your logic here
        System.out.println("Application started successfully!");
        upgradeService.handleDBUpdate_v.10();


    }
}

4. Using InitializingBean interface:

The below is sample code for Initializing Bean:

import org.springframework.beans.factory.InitializingBean;
import org.springframework.stereotype.Component;

@Component
public class StartupLogicRunner implements InitializingBean {
  
   @Autowired
   private UpgradeService upgradeService;

    @Override
    public void afterPropertiesSet() throws Exception {
        // Your logic here
        System.out.println("Application started successfully!");
        upgradeService.handleDBUpdate_v.10();


    }
}

5. Using CommandLineRunner

The below is sample for CommandLineRunner

@Component
public class StartupRunner implements CommandLineRunner {
    

    @Override
    public void run(String...args) throws Exception {
        
          System.out.println("Application started successfully!");


    }
}

Thanks for Reading…