如何从junit测试中调用SpringBoot应用程序的main方法并使其停止

Question

I have a very simple SpringBoot application that exposes a rest endpoint at localhost:8085.

@SpringBootApplication
public class App 
{
    public static void main(String[] args)
    {
        SpringApplication.run(App.class, args);
        System.out.println("The gOaT");
    }
}

---

@RestController
public class Enpoints {

    @RequestMapping("/goat")
    public String home() {
        return "Goat";
    }
}

---

I'd like to start my application in a junit test. This succeeds in doing so:

public class SomeTest extends TestCase {

    @Test
    public void testOne() {
        String[] args = new String[0];
        App.main(args);
        assertTrue(true);
    }

}

The problem is, once the unit test initializes the application, it immediately shuts it down too (I think this is because the unit test itself terminates):

2018-08-01 21:20:43.422  INFO 4821 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8085 (http) with context path ''
2018-08-01 21:20:43.428  INFO 4821 --- [           main] com.boot.BootTraining.App                : Started App in 3.168 seconds (JVM running for 3.803)
The gOaT
2018-08-01 21:20:43.468  INFO 4821 --- [       Thread-3] ConfigServletWebServerApplicationContext : Closing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@56dc1551: startup date [Wed Aug 01 21:20:40 CDT 2018]; root of context hierarchy
2018-08-01 21:20:43.470  INFO 4821 --- [       Thread-3] o.s.j.e.a.AnnotationMBeanExporter        : Unregistering JMX-exposed beans on shutdown

How can I run this test, start the application, and then keep the application from closing?

Answer 1

Annotate you test class with:

@RunWith(SpringRunner.class)
@SpringBootTest(classes = App.class, webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)

It will load the application into the context and keep your application running.

Answer 2

For testing rest apis, you either need mockmvc or a similar sort of framework. Annotate your class with

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)

I do have a sample project that might be helpful for you to get start up: https://github.com/dhananjay12/test-frameworks-tools/tree/master/test-rest-assured