Springboot Annotation

@SpringBootApplication
public class DemoApplication {
   public static void main(String[] args) {
      SpringApplication.run(DemoApplication.class, args);
   }
}

@SpringBootApplication 封装：@Configuration, @EnableAutoConfiguration,@ComponentScan annotations 

@ComponentScan({"controller","service","repository","pojo"}) @EnableJpaRepositories("repository") @EntityScan("pojo") @EnableAutoConfiguration @Configuration public class Config { .... }

condition annotations are used on @Configuration  @Bean @Configuration @ConditionalOnClass(DataSource.class) class DataSourceCfg { } @ConditionalOnClass and @ConditionalOnMissingClass @ConditionalOnBean and @ConditionalOnMissingBean  @ConditionalOnProperty @ConditionalOnResource @ConditionalOnWebApplication and @ConditionalOnNotWebApplication @ConditionalExpression @Conditional

@EnableAutoConfiguration @ExtendWith(SpringExtension.class) @ContextConfiguration(classes = Config.class) //@PropertySource("classpath:application.properties") @TestPropertySource(locations ="classpath:application.properties") @ConfigurationProperties("spring.datasource") //@Import (Config.class) public class RepositoryTest { @Autowired Environment env; @Test void printEnv() { System.out.println(env.getProperty("spring.datasource.url")); System.out.println(env.getProperty("spring.datasource.driverClassName")); } } ------------------------------------------------------------------------- @PropertySource("classpath:db.properties") @PropertySource("classpath:server.properties") class SysCfg {         @Value( "${spring.datasource.url}" )         private String jdbcUrl;           //with default value         @Value( "${spring.datasource.driverClassName:com.mysql.jdbc.Driver}" )         private String jdbcDriver; } ------------------------------------------------------------------------- @PropertySources({ @PropertySource("classpath:db.properties") @PropertySource("classpath:server.properties") }） class SysCfg {             @Autowired         Environment env; }

application.properties is the default file under folder src/main/resources application-dev.properties application-uat.properties

@Component @Profile("dev") public class DevDatasourceConfig{}

java -jar xxx.jar --spring.profiles.active=dev

-Dspring.profiles.active=dev

application.properties中定义： spring.profiles.active = dev

@Autowired private ConfigurableEnvironment env; ... env.setActiveProfiles("dev");

servletContext.setInitParameter"spring.profiles.active", "dev");

web.xml file     spring.profiles.active     dev

@ActiveProfiles("dev")

@Value("${spring.profiles.active:}") private String activeProfile;

@RunWith(SpringRunner.class) @TestPropertySource("/foo.properties") public class FilePropertyInjectionUnitTest { @Value("${foo}") private String foo; @Test public void whenFilePropertyProvided_thenProperlyInjected() { assertThat(foo).isEqualTo("bar"); } }

@RunWith(SpringRunner.class) @SpringBootTest( webEnvironment = SpringBootTest.WebEnvironment.MOCK, classes = Application.class) @AutoConfigureMockMvc @TestPropertySource( locations = "classpath:application-dev.properties") public class ControllerTest { @Autowired private MockMvc mvc; @Autowired private EmployeeRepository repository; }

@RunWith(SpringRunner.class) public class EmployeeServiceImplIntegrationTest { @TestConfiguration static class EmployeeServiceImplTestContextConfiguration { @Bean public EmployeeService employeeService() { return new EmployeeService() { // implement methods }; } } @Autowired private EmployeeService employeeService; }

@TestConfiguration public class EmployeeServiceImplTestContextConfiguration {          @Bean     public EmployeeService employeeService() {         return new EmployeeService() {              // implement methods          };     } } @RunWith(SpringRunner.class) @Import(EmployeeServiceImplTestContextConfiguration.class) public class EmployeeServiceImplIntegrationTest {     @Autowired     private EmployeeService employeeService;     // remaining class code }

@RunWith(SpringRunner.class) public class EmployeeServiceImplIntegrationTest {     @TestConfiguration     static class EmployeeServiceImplTestContextConfiguration {           @Bean         public EmployeeService employeeService() {             return new EmployeeServiceImpl();         }     }     @Autowired     private EmployeeService employeeService;     @MockBean     private EmployeeRepository employeeRepository;     // write test cases here }

@RunWith(SpringRunner.class) @DataJpaTest public class EmployeeRepositoryIntegrationTest {     @Autowired     private TestEntityManager entityManager;     @Autowired     private EmployeeRepository employeeRepository;     // write test cases here }

@RunWith(SpringRunner.class) @WebMvcTest(EmployeeRestController.class) public class EmployeeRestControllerIntegrationTest {     @Autowired     private MockMvc mvc;     @MockBean     private EmployeeService service;     // write test cases here }

 links:

 Properties with Spring and Spring Boot | Baeldung

Spring Boot Tutorial - Learn Spring Boot

Spring Boot Reference Documentation