How do I execute a method in Spring when the Server is ready?

Question

I have the following problem: I'm using Spring-Boot for a little private web-based project and I want Spring to make a call to a webservice when it's started. And by started I mean "when my application is ready to handle requests".

I've already tried implementing the ApplicationListener<ContextRefreshedEvent> but it did not work, as the Event happend to early (i.e. before the embedded server was ready to handle request). Also the options mentioned in this question did not solve this problem.

My question now is: Is there any possibilty to tell Spring to execute something after the server has finished starting up and is ready to handle requests?

EDIT (in response to Daniel's answer):

The problem is that I need some injected properties to make that webservice call, and since injecting static values does not work in spring this approach is no option.

My listener, that does what I want, just a bit too early looks something like this:



@Component
public class StartupListener implements ApplicationListener{


    @Autowired
    private URLProvider urlProvider;
    @Value("${server.port}")
    private int port;
    @Value("${project.name}")
    private String projectName;

    @Override
    public final void onApplicationEvent(ContextRefreshedEvent event) {
        RestTemplate template = new RestTemplate();
        String url = uriProvider.getWebserviceUrl(this.projectName);
        template.put(url, null);
    }

}

SECOND EDIT:

Although this question solves a very similar problem it seems like I'm not able to inject into the object because it needs to have a constructor of the form (org.springframework.boot.SpringApplication, [Ljava.lang.String;).

Also it would be desirebale to solve it without having to create the spring.factories file but by using annotations.

Hmm, does your application use Spring MVC for its web part or another framework or no framework at all ? — Serge Ballesta, Apr 23 '15 at 13:21
possible duplicate of [Spring Boot - Wait for web server to start](http://stackoverflow.com/questions/28240403/spring-boot-wait-for-web-server-to-start) — Andy Wilkinson, Apr 23 '15 at 20:11

score 1 · Answer 1 · answered Apr 23 '15 at 13:21

1

If I understand what your problem is, you could call the webservice on your application main, right after it initiates.

public static void main(String[] args) {

        new SpringApplication(Application.class).run(args);
        //call the webservice for you to handle...
    }

I'm not sure if this is what you want...

answered Apr 23 '15 at 13:21

danielgmarcos

174
2
9

The problem is, that I need some injected properties to make the webservice call and static injection does not really work, as far as I have read. – wastl Apr 23 '15 at 13:41
Can you provide an example? From spring documentation you could perform a request like this: public static void main(String args[]) { RestTemplate restTemplate = new RestTemplate(); Page page = restTemplate.getForObject("http://graph.facebook.com/pivotalsoftware", Page.class); System.out.println("Name: " + page.getName()); System.out.println("About: " + page.getAbout()); System.out.println("Phone: " + page.getPhone()); System.out.println("Website: " + page.getWebsite()); } – danielgmarcos Apr 23 '15 at 13:49
please see my edit (unfortunately, it is not possible to hardwire all the variables) – wastl Apr 23 '15 at 13:54

score 0 · Answer 2 · answered Apr 23 '15 at 13:55

0

In your component you can use the @PostConstruct annotation. e.g.

@Component
public class StartupListener {


    @Autowired
    private URLProvider urlProvider;
    @Value("${server.port}")
    private int port;
    @Value("${project.name}")
    private String projectName;

    @PostConstruct
    public final void init() {
        RestTemplate template = new RestTemplate();
        String url = uriProvider.getWebserviceUrl(this.projectName);
        template.put(url, null);
    }

}

This will fire once the bean has been initialised and autowiring has taken place.

answered Apr 23 '15 at 13:55

extols

1,762
14
19

unfortunately this does not work, since the application is not completly started when this method is called. – wastl Apr 23 '15 at 14:04
Can you explain what you mean by "not completely started"? – extols Apr 23 '15 at 15:21
Completley started means (as mentioned in the question) that the server is ready to handle requests. Because the application is going to be called back from the webservice. – wastl Apr 23 '15 at 15:44

PTT · Answer 3 · 2020-09-24T18:11:17.233

  @Component
  public class StartUp implements ApplicationListener<WebServerInitializedEvent> {

  private WebClient webClient;

  @Override
  public void onApplicationEvent(WebServerInitializedEvent event) {

    String baseUrl = "http://url.com"
    webClient = WebClient.create(baseUrl);
    executeRestCall(baseUrl+"/info");
  }

  void executeRestCall(String uri) {
    try {
      webClient.get()
          .uri(uri)
          .exchange()
          .block();
    } catch (Exception e) {
      log.error("Request failed for url - {}",uri, e);
    }
  }}

How do I execute a method in Spring when the Server is ready?

3 Answers3