Spring Boot 2.0 web app wont start embedded servlet container

Question

I've upgraded a working Spring Boot 1.4 web app to 2.0.5 I followed the migration guide and worked through the various compiler errors. When running the app via IntelliJ I now only get

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.0.5.RELEASE)


Process finished with exit code 0

Tried running with debug output, nothing additional

It seems like it's not starting an embedded servlet container, so I after looking at change logs for Spring 2.0 I added the following to the config

spring.main.web-application-type=servlet

Read some more and checked that

compile('org.springframework.boot:spring-boot-starter-web')

is in my build.grade, which it is. It's also pulling in as a dependency

spring-boot-starter-tomcat

I then tried creating and use a simple test Main class

@RestController
@SpringBootApplication
public class TestApp {

    @RequestMapping("/")
    String home() {
        return "Hello World!";
    }

    public static void main(String[] args) throws Exception {
        SpringApplication.run(TestApp.class, args);
    }

}

but still "exit code 0".

I also tried removing everything from my application.properties when using the class above.

Given there are no errors, I'm not sure where to go from here.

Answer 1

There are two ways you can fix this probelm..

Approach 1:

@SpringBootApplication
public class TestApp {

    @GetMapping("/")
    String home() {
        return "Hello World!";
    }

    public static void main(String[] args) throws Exception {
        SpringApplication.run(TestApp.class, args);
    }

}

Approach 2

STEP 1: Your main class will have only main method:

@SpringBootApplication
public class TestApp {


    public static void main(String[] args) throws Exception {
        SpringApplication.run(TestApp.class, args);
    }

}

STEP 2: Create TestController and put your methods here like below:

@RestController
public class TestController {

    @GetMapping("/")
    String home() {
        return "Hello World!";
    }

}