CODEWITHSUNDEEP
javaspringspring-boot
Steffen Harbich
Steffen Harbich

Reputation: 2749

Ensure code is executed before webserver exposing HTTP in spring boot

In spring boot web application, is it possible to ensure some code is executed before the embedded webserver (tomcat) is listening for incoming requests?

I have some data base migration scripts that need to be run before any request from my REST API is responded by the application. How can I do that? For now, my migration script component uses @EventListener for ContextRefreshedEvent but that is too late. The following line is already logged before:

o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8091 (http) with context path ''

Upvotes: 2

Views: 851

Answers (2)

JArgente
JArgente

Reputation: 2297

You can use @PostConstruct method in the bean that you use to connect to the database (repository) and write there the code you need to run the scripts, this code is going to be executed after the bean is created but before the server is running.

Example: https://www.baeldung.com/spring-postconstruct-predestroy

Upvotes: 1

Steffen Harbich
Steffen Harbich

Reputation: 2749

I used the following approach finally:

@Component
public class MigrationLogic implements SmartInitializingSingleton {

    @Override
    @Transactional
    public void afterSingletonsInstantiated() {
        // run your logic here, declare dependencies with @Autowired
    }

}

The SmartInitializingSingleton executes before the web server is starting up.

Upvotes: 1

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