Spring Boot @DynamicPropertySource Example

In Spring Boot, we can use @DynamicPropertySource to dynamically register or override property values in the ApplicationContext for integration tests.

Tables of contents:

• 1. Testing with ApplicationContextInitializer
• 2. Testing with @DynamicPropertySource
• 3. Testing with Spring Boot 3.1 and @ServiceConnection
• 4. Download Source Code
• 5. References

P.S. The @DynamicPropertySource feature is available from Spring Framework 5.2.5 and Spring Boot 2.3.1 onwards.

1. Testing with ApplicationContextInitializer

Before Spring 5.2.5, it was necessary to use @ContextConfiguration and ApplicationContextInitializer to set up dynamic property values for integration tests.

@DataJpaTest
@AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)
@ContextConfiguration(initializers = BookRepositoryDynamicPropertyTest.Initializer.class)
@Testcontainers
public class BookRepositoryDynamicPropertyTest {

  @Autowired
  private BookRepository bookRepository;

  @Container
  static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>(
          "postgres:15-alpine"
  );

  // register dynamic properties like this
  static class Initializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {
      @Override
      public void initialize(ConfigurableApplicationContext applicationContext) {
          TestPropertyValues.of(
                  "spring.datasource.url=" + postgres.getJdbcUrl(),
                  "spring.datasource.username=" + postgres.getUsername(),
                  "spring.datasource.password=" + postgres.getPassword()
          ).applyTo(applicationContext);

      }
  }

}

2. Testing with @DynamicPropertySource

Spring 5.2.5+ introduced the @DynamicPropertySource annotation to improve the registration of the dynamic property values. The following example demonstrates how to use @DynamicPropertySource to register dynamic data source properties into integration tests using @Testcontainers.

import org.springframework.test.context.DynamicPropertyRegistry;
import org.springframework.test.context.DynamicPropertySource;

@DataJpaTest
@AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)
@Testcontainers
public class BookRepositoryDynamicPropertyTest {

    @Autowired
    private BookRepository bookRepository;

    @Container
    static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>(
            "postgres:15-alpine"
    );

    // no more ApplicationContextInitializer
    @DynamicPropertySource
    static void configureProperties(DynamicPropertyRegistry registry) {
        registry.add("spring.datasource.url", postgres::getJdbcUrl);
        registry.add("spring.datasource.username", postgres::getUsername);
        registry.add("spring.datasource.password", postgres::getPassword);
    }

    @Test
    public void testEmptyList() {

        List<Book> result = bookRepository.findAll();
        assertEquals(0, result.size());

    }
}

3. Testing with Spring Boot 3.1 and @ServiceConnection

Spring Boot 3.1 introduced @ServiceConnection to enable the Spring Boot’s auto-configuration to automatically use the service connection details to connect to a remote service (Testcontainers).

@DataJpaTest
@AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)
@Testcontainers
public class BookRepositoryDynamicPropertyTest {

    @Autowired
    private BookRepository bookRepository;

    @Container
    @ServiceConnection // no more @DynamicPropertySource
    static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>(
            "postgres:15-alpine"
    );

    /*@DynamicPropertySource
    static void configureProperties(DynamicPropertyRegistry registry) {
        registry.add("spring.datasource.url", postgres::getJdbcUrl);
        registry.add("spring.datasource.username", postgres::getUsername);
        registry.add("spring.datasource.password", postgres::getPassword);
    }*/

}

4. Download Source Code

5. References

• Integration tests with a dynamic property source
• SpringDoc @DynamicPropertySource
• Context Configuration with Dynamic Property Sources
• Spring Boot and Testcontainers
• Spring Test using Testcontainers
• Testcontainers Postgres Module
• Spring Boot Testcontainers example
• Spring data JPA and MySQL example
• Spring Data JPA and PostgreSQL example
• Testing Spring Data JPA with @DataJpaTest

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