How to configure port for a Spring Boot application

Question

How do I configure the TCP/IP port listened on by a Spring Boot application, so it does not use the default port of 8080.

Answer 1

To extend other answers:

There is a section in the docs for testing which explains how to configure the port on integration tests:

• 41.3 Testing Spring Boot applications
• 41.3.3 Working with random ports

---

At integration tests, the port configuration is made using the annotation @SpringBootTest and the webEnvironment values.

---

Random port:

@SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT)

You can inject the value using @LocalServerPort which is the same as @Value("${local.server.port}").

• Example:

Random port test configuration:

@RunWith(SpringRunner.class
@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
public class ExampleTest {
   ...
   @LocalServerPort //to inject port value
   int port;
}

---

Defined port:

@SpringBootTest(webEnvironment=WebEnvironment.DEFINED_PORT)

It takes the value from server.port if is defined.

• If is defined using @TestPropertySource(properties = "server.port=9192"), it overrides other defined values.
• If not, it takes the value from src/test/resources/application.properties (if exists).
• And finally, if it is not defined it starts with the default 8080.

Example:

Defined port test configuration:

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.DEFINED_PORT)
@TestPropertySource(properties = "server.port=9192")
public class DemoApplicationTests {

    @Test
    public void contextLoads() {
    }

}