How can I get a list of instantiated beans from Spring?

Question

I have several beans in my Spring context that have state, so I\'d like to reset that state before/after unit tests.

My idea was to add a method to a helper class wh

Answer 1

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

package io.velu.core;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@ComponentScan
public class Core {

public static void main(String[] args) {
    AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(Core.class);
    String[] singletonNames = context.getDefaultListableBeanFactory().getSingletonNames();
    for (String singleton : singletonNames) {
        System.out.println(singleton);
    }       
}

}

---

Console Output

environment
systemProperties
systemEnvironment
org.springframework.context.annotation.internalConfigurationAnnotationProcessor
org.springframework.context.annotation.ConfigurationClassPostProcessor.importRegistry
org.springframework.context.event.internalEventListenerProcessor
org.springframework.context.event.internalEventListenerFactory
org.springframework.context.annotation.internalAutowiredAnnotationProcessor
org.springframework.context.annotation.internalCommonAnnotationProcessor
messageSource
applicationEventMulticaster
lifecycleProcessor

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

Spring Boot

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" ]