How to prevent Spring Boot daemon/server application from closing/shutting down immediately?

Question

My Spring Boot application is not a web server, but it\'s a server using custom protocol (using Camel in this case).

But Spring Boot immediately stops (gracefully) a

Answer 1

Spring Boot leaves the task of running the application to the protocol around which the application is implemented. See, for example, this guide:

Also required are some housekeeping objects like a CountDownLatch to keep the main thread alive...

So the way of running a Camel service, for example, would to be to run Camel as a standalone application from your main Spring Boot application class.

Answer 2

As of Apache Camel 2.17 there is a cleaner answer. To quote http://camel.apache.org/spring-boot.html:

To keep the main thread blocked so that Camel stays up, either include the spring-boot-starter-web dependency, or add camel.springboot.main-run-controller=true to your application.properties or application.yml file.

You will want the following dependency too:

<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-spring-boot-starter</artifactId> <version>2.17.0</version> </dependency>

Clearly replace <version>2.17.0</version> or use the camel BOM to import dependency-management information for consistency.

Answer 3

All threads are completed, the program will close automatically. So, register an empty task with @Scheduled will create a loop thread to prevent shutdown.