Integration tests on spring-boot throws Connection refused - spring-boot

Question

I have an unit test on Spring Boot:
#RunWith(SpringJUnit4ClassRunner.class)
#SpringBootTest(classes = Application.class)
public class CustomerControllerIT {
private RestTemplate restTemplate = new RestTemplate();
#Test
public void findAllCustomers() throws Exception {
ResponseEntity<List<Customer>> responseEntity = restTemplate.exchange(
"http://localhost:8080/Customer", HttpMethod.GET, null,
new ParameterizedTypeReference<List<Customer>>() {
});
List<Customer> list = responseEntity.getBody();
Assert.assertEquals(list.size(), 0);
}
}
If I launch test on started application - tests ok
If I try to launch only IT, there is connection refused error
My application.properties is same for single start.
For tests and located in resources and testResources.
Application.class is:
#ComponentScan({"mypackage"})
#EntityScan(basePackages = {"mypackage.model"})
#EnableJpaRepositories(basePackages = {"mypackage.persistence"})
#SpringBootApplication
public class Application extends SpringBootServletInitializer {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}

Answer 1

You must run a test with a running server ,
If you need to start a full running server, you can use random ports:
#SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT)
An available port is picked at random each time your test runs
You need this maven dependency:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-test</artifactId>
</dependency>
Example:
#RunWith(SpringRunner.class)
#SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT)
public class TestRest {
#Autowired
private TestRestTemplate restTemplate;
#Test
public void findAllCustomers() throws Exception {
ResponseEntity<List<Customer>> responseEntity = restTemplate.exchange(
"/Customer", HttpMethod.GET, null,
new ParameterizedTypeReference<List<Customer>>(){});
List<Customer> list = responseEntity.getBody();
Assert.assertEquals(list.size(), 0);
}
}
Please read the documentation for more reference

Answer 2

For running #SpringBootTest and JUnit5 (Jupiter) with static port you can use:
#ExtendWith(SpringExtension.class)
#SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.DEFINED_PORT)
class MyUnitTests {
#Test
void checkActuator() throws Exception {
final String url = "http://localhost:8080/actuator/health";
#SuppressWarnings("rawtypes")
ResponseEntity<Map> re = new RestTemplate().getForEntity(url, Map.class);
System.out.println(re);
assertEquals(HttpStatus.OK, re.getStatusCode());
re.getStatusCode();
}
}
If you're using JUnit 4:
Change: #ExtendWith(SpringExtension.class)
To: #RunWith(SpringRunner.class)
And then add the port property to your application.yml (inside folder src/main/resources):
server:
port: 8080
Or if have an application.properties:
server.port=8080
Reference:
How to configure port for a Spring Boot application
https://www.baeldung.com/spring-boot-change-port
Test the SpringBoot application startup