52

How can I get to know names of all the beans that are loaded as part of my spring boot app? I would like have some code in main method to print the details of beans that are loaded once the server is started up.

Punter Vicky
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  • Possible duplicate of [How can I get a list of instantiated beans from Spring?](http://stackoverflow.com/questions/14829258/how-can-i-get-a-list-of-instantiated-beans-from-spring) – Robert Moskal Oct 26 '15 at 15:05

9 Answers9

67

As shown in the getting started guide of spring-boot: https://spring.io/guides/gs/spring-boot/

@SpringBootApplication
public class Application {

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

As @Velu mentioned in the comments, this will not list manually registered beans.

In case you want to do so, you can use getSingletonNames(). But be careful. This method only returns already instantiated beans. If a bean isn't already instantiated, it will not be returned by getSingletonNames().

Yannic Bürgmann
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    applicationContext.getBeanDefinitionNames() does not show the beans which are registered without BeanDefinition instance. You will not be able to list singleton beans which are registered manually. ex-:) you can not list environment, systemProperties,systemEnvironment beans. However these beans are available in the container. You can autowire them using @Auwired Environment env etc. https://stackoverflow.com/a/54881338/1840774 – Velu Feb 26 '19 at 08:33
  • You're right. But getSingletonNames brings other downsides. I updated my answer accordingly – Yannic Bürgmann Feb 26 '19 at 09:10
23

May I suggest using Actuator? it provides several endpoints including /beans which lists all beans in the application. You say "once the server is started" so this is an option for web applications.

To set up actuator

https://spring.io/guides/gs/actuator-service/

List of endpoints in actuator

http://docs.spring.io/spring-boot/docs/current/reference/html/production-ready-endpoints.html

Zergleb
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13

Well, Although, this question is already answered, I still want to provide an answer which is a Java 8 variant :)

Arrays.asList(context.getBeanDefinitionNames()).stream().sorted().forEach(System.out::println);

Lets do Java 8 !!!

zikzakjack
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4

Actually I would recommend to create this class aside from modifying your @SpringBootApplication.

@Component
public class ContextTeller implements CommandLineRunner {

@Autowired
ApplicationContext applicationContext;

@Override
public void run(String... args) throws Exception {
    System.out.println("-------------> just checking!");

        System.out.println(Arrays.asList(applicationContext.getBeanDefinitionNames()));

}}

This way Spring Boot will load this class and execute just after loading context. Then you just can remove the file, and everything is clear.

jfzr
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4

applicationContext.getBeanDefinitionNames() does not show the beans which are registered without BeanDefinition instance.

For spring boot web applications, all the beans can be listed using the below endpoint.

@RestController
@RequestMapping("/list")
class ExportController {

@Autowired
private ApplicationContext applicationContext;

@GetMapping("/beans")
@ResponseStatus(value = HttpStatus.OK)
String[] registeredBeans() {
    return printBeans();
}

private String[] printBeans() {
    AutowireCapableBeanFactory autowireCapableBeanFactory = applicationContext.getAutowireCapableBeanFactory();
    if (autowireCapableBeanFactory instanceof SingletonBeanRegistry) {
        String[] singletonNames = ((SingletonBeanRegistry) autowireCapableBeanFactory).getSingletonNames();
        for (String singleton : singletonNames) {
            System.out.println(singleton);
        }
        return singletonNames;
    }
    return null;
}

}


[ "autoConfigurationReport", "springApplicationArguments", "springBootBanner", "springBootLoggingSystem", "environment", "systemProperties", "systemEnvironment", "org.springframework.context.annotation.internalConfigurationAnnotationProcessor", "org.springframework.boot.autoconfigure.internalCachingMetadataReaderFactory", "org.springframework.boot.autoconfigure.condition.BeanTypeRegistry", "org.springframework.context.annotation.ConfigurationClassPostProcessor.importRegistry", "propertySourcesPlaceholderConfigurer", "org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor.store", "preserveErrorControllerTargetClassPostProcessor", "org.springframework.context.annotation.internalAutowiredAnnotationProcessor", "org.springframework.context.annotation.internalRequiredAnnotationProcessor", "org.springframework.context.annotation.internalCommonAnnotationProcessor", "org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor", "org.springframework.scheduling.annotation.ProxyAsyncConfiguration", "org.springframework.context.annotation.internalAsyncAnnotationProcessor", "methodValidationPostProcessor", "embeddedServletContainerCustomizerBeanPostProcessor", "errorPageRegistrarBeanPostProcessor", "messageSource", "applicationEventMulticaster", "org.springframework.boot.autoconfigure.web.EmbeddedServletContainerAutoConfiguration$EmbeddedTomcat", "tomcatEmbeddedServletContainerFactory", "org.springframework.boot.autoconfigure.websocket.WebSocketAutoConfiguration$TomcatWebSocketConfiguration", "websocketContainerCustomizer", "spring.http.encoding-org.springframework.boot.autoconfigure.web.HttpEncodingProperties", "org.springframework.boot.autoconfigure.web.HttpEncodingAutoConfiguration", "localeCharsetMappingsCustomizer", "org.springframework.boot.autoconfigure.web.ServerPropertiesAutoConfiguration", "serverProperties", "duplicateServerPropertiesDetector", "spring.resources-org.springframework.boot.autoconfigure.web.ResourceProperties", "org.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration$DefaultErrorViewResolverConfiguration", "conventionErrorViewResolver", "org.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration", "errorPageCustomizer", "servletContext", "contextParameters", "contextAttributes", "spring.mvc-org.springframework.boot.autoconfigure.web.WebMvcProperties", "spring.http.multipart-org.springframework.boot.autoconfigure.web.MultipartProperties", "org.springframework.boot.autoconfigure.web.MultipartAutoConfiguration", "multipartConfigElement", "org.springframework.boot.autoconfigure.web.DispatcherServletAutoConfiguration$DispatcherServletRegistrationConfiguration", "org.springframework.boot.autoconfigure.web.DispatcherServletAutoConfiguration$DispatcherServletConfiguration", "dispatcherServlet", "dispatcherServletRegistration", "requestContextFilter", "org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration", "hiddenHttpMethodFilter", "httpPutFormContentFilter", "characterEncodingFilter", "org.springframework.context.event.internalEventListenerProcessor", "org.springframework.context.event.internalEventListenerFactory", "reportGeneratorApplication", "exportController", "exportService", "org.springframework.boot.autoconfigure.AutoConfigurationPackages", "org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration", "org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration$Jackson2ObjectMapperBuilderCustomizerConfiguration", "spring.jackson-org.springframework.boot.autoconfigure.jackson.JacksonProperties", "standardJacksonObjectMapperBuilderCustomizer", "org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration$JacksonObjectMapperBuilderConfiguration", "org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration", "jsonComponentModule", "jacksonObjectMapperBuilder", "org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration$JacksonObjectMapperConfiguration", "jacksonObjectMapper", "org.springframework.boot.autoconfigure.websocket.WebSocketAutoConfiguration", "org.springframework.boot.autoconfigure.web.EmbeddedServletContainerAutoConfiguration", "org.springframework.boot.autoconfigure.web.DispatcherServletAutoConfiguration", "org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration", "defaultValidator", "org.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration$WhitelabelErrorViewConfiguration", "error", "beanNameViewResolver", "errorAttributes", "basicErrorController", "org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration$EnableWebMvcConfiguration", "org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter", "mvcContentNegotiationManager", "org.springframework.boot.autoconfigure.web.HttpMessageConvertersAutoConfiguration$StringHttpMessageConverterConfiguration", "stringHttpMessageConverter", "org.springframework.boot.autoconfigure.web.JacksonHttpMessageConvertersConfiguration$MappingJackson2HttpMessageConverterConfiguration", "mappingJackson2HttpMessageConverter", "org.springframework.boot.autoconfigure.web.HttpMessageConvertersAutoConfiguration", "messageConverters", "mvcConversionService", "mvcValidator", "requestMappingHandlerAdapter", "mvcResourceUrlProvider", "requestMappingHandlerMapping", "mvcPathMatcher", "mvcUrlPathHelper", "viewControllerHandlerMapping", "beanNameHandlerMapping", "resourceHandlerMapping", "defaultServletHandlerMapping", "mvcUriComponentsContributor", "httpRequestHandlerAdapter", "simpleControllerHandlerAdapter", "handlerExceptionResolver", "mvcViewResolver", "org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter$FaviconConfiguration", "faviconRequestHandler", "faviconHandlerMapping", "defaultViewResolver", "viewResolver", "welcomePageHandlerMapping", "org.springframework.boot.autoconfigure.jmx.JmxAutoConfiguration", "objectNamingStrategy", "mbeanServer", "mbeanExporter", "org.springframework.boot.autoconfigure.admin.SpringApplicationAdminJmxAutoConfiguration", "springApplicationAdminRegistrar", "org.springframework.boot.autoconfigure.context.ConfigurationPropertiesAutoConfiguration", "org.springframework.boot.autoconfigure.web.JacksonHttpMessageConvertersConfiguration", "spring.info-org.springframework.boot.autoconfigure.info.ProjectInfoProperties", "org.springframework.boot.autoconfigure.info.ProjectInfoAutoConfiguration", "multipartResolver", "org.springframework.boot.autoconfigure.web.WebClientAutoConfiguration$RestTemplateConfiguration", "restTemplateBuilder", "org.springframework.boot.autoconfigure.web.WebClientAutoConfiguration", "spring.devtools-org.springframework.boot.devtools.autoconfigure.DevToolsProperties", "org.springframework.boot.devtools.autoconfigure.LocalDevToolsAutoConfiguration$RestartConfiguration", "fileSystemWatcherFactory", "classPathRestartStrategy", "classPathFileSystemWatcher", "hateoasObjenesisCacheDisabler", "org.springframework.boot.devtools.autoconfigure.LocalDevToolsAutoConfiguration$LiveReloadConfiguration$LiveReloadServerConfiguration", "org.springframework.boot.devtools.autoconfigure.LocalDevToolsAutoConfiguration$LiveReloadConfiguration", "optionalLiveReloadServer", "org.springframework.boot.devtools.autoconfigure.LocalDevToolsAutoConfiguration", "lifecycleProcessor" ]

As you can see in the output, environment, systemProperties, systemEnvironment beans will not be shown using context.getBeanDefinitionNames() method.

Velu
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3
@Component
public class ContextTeller implements CommandLineRunner {

    @Autowired
    public ApplicationContext applicationContext;

    @Override
    public void run(String... args) throws Exception {
        System.out.println("<------------- Beans loaded --------------->");
Arrays.asList(applicationContext.getBeanDefinitionNames()).stream().forEach(System.out::println);
    }
}
ZIA
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3

I did one small experiment for this requirement and found this solution. I have created SpringBoot while selecting the modules like WEB, Actuator, HAL and Devtools. I have configured the below property in application properties to load all the endpoints present in actuator.

management.endpoints.web.exposure.include=*

You can see actuator information in, http://localhost:8080/actuator. This will show all the application information along with actuator, status, info,etc.. In that, you can find the http://localhost:8080/actuator/beans which will load all the beans internally created by springboot application.

Once you are able to see all the beans information, I think it's not necessary to print again in main class.

Since, I have already configured rest-hal-browser dependency in my application, when I load the URL of http://localhost:8080, will load the UI to search for different endpoints. In the below image I am searching for actuator information.

enter image description here

Nallamachu
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3

As mentioned by @Zergleb, using Actuator is appropriate too, however, based on the reference documentation this endpoint is no longer exposed via "web" by default. Thus you need to consider the following steps to access the endpoint

  1. Add the below dependency to your pom.xml

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>
    
  2. Add these two propertiers to your application.properties file:

management.endpoints.web.exposure.include=beans

management.endpoint.beans.enabled=true

  1. Access to your application context beans using /actuator/beans http endpoint
Ikbel
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0

Simple way to get all beans

ApplicationContext ctx =SpringApplication.run(DemoApplication.class, args);
String [] beans = ctx.getBeanDefinitionNames();
Arrays.sort(beans);
System.out.println("#############");
for(String s:beans) {
    System.out.println(s + "  of type " + ctx.getBean(s).getClass());
}
Andronicus
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