企业分布式微服务云SpringCloud SpringBoot mybatis （十八）springboot在启动时注入了哪些bean

在程序入口加入：@SpringBootApplication
public class SpringbootFirstApplication {

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

@Bean
public CommandLineRunner commandLineRunner(ApplicationContext ctx) {
return args -> {

System.out.println("Let's inspect the beans provided by Spring Boot:");

String[] beanNames = ctx.getBeanDefinitionNames();
Arrays.sort(beanNames);
for (String beanName : beanNames) {
System.out.println(beanName);
}

};
}

}
程序输出：Let’s inspect the beans provided by Spring Boot:
basicErrorController
beanNameHandlerMapping
beanNameViewResolver
characterEncodingFilter
commandLineRunner
conventionErrorViewResolver
defaultServletHandlerMapping
defaultViewResolver
dispatcherServlet
dispatcherServletRegistration
duplicateServerPropertiesDetector
embeddedServletContainerCustomizerBeanPostProcessor
error
errorAttributes
errorPageCustomizer
errorPageRegistrarBeanPostProcessor

….
….
在程序启动的时候，springboot自动诸如注入了40-50个bean.通过@RunWith() @SpringBootTest开启注解：@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class HelloControllerIT {

@LocalServerPort
private int port;

private URL base;

@Autowired
private TestRestTemplate template;

@Before
public void setUp() throws Exception {
this.base = new URL("http://localhost:" + port + "/");
}

@Test
public void getHello() throws Exception {
ResponseEntity<String> response = template.getForEntity(base.toString(),
String.class);
assertThat(response.getBody(), equalTo("Greetings from Spring Boot!"));
}
}
运行它会先开启sprigboot工程，然后再测试，测试通过 

源码来源