Print all beans loaded by Spring Boot

In this post, we will see how to print all the beans loaded by Spring boot.

We have already created a sample spring boot hello world program using JSP. You must be wondering what beans have been loaded by Spring in background.

Change SpringBootHelloWorldApplication.java as below:

package org.arpit.java2blog;

import java.util.Arrays;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.boot.CommandLineRunner;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.context.ApplicationContext;

@SpringBootApplication

public class SpringBootHelloWorldApplication implements CommandLineRunner {

@Autowired

private ApplicationContext appContext;

public static void main(String[] args)

{

SpringApplication.run(SpringBootHelloWorldApplication.class, args);

}

@Override

public void run(String... arg0) throws Exception {

String[] beans = appContext.getBeanDefinitionNames();

Arrays.sort(beans);

for (String bean : beans) {

System.out.println(bean);

}

You just need to implement CommandLineRunner and get ApplicatationContext object using @Autowire annotation.

basicErrorController
beanNameHandlerMapping
beanNameViewResolver
characterEncodingFilter
conventionErrorViewResolver
defaultServletHandlerMapping
defaultValidator
defaultViewResolver
dispatcherServlet
dispatcherServletRegistration
duplicateServerPropertiesDetector
embeddedServletContainerCustomizerBeanPostProcessor
error
errorAttributes
errorPageCustomizer
errorPageRegistrarBeanPostProcessor
faviconHandlerMapping
faviconRequestHandler
handlerExceptionResolver
helloWorldController
hiddenHttpMethodFilter
httpPutFormContentFilter
httpRequestHandlerAdapter
jacksonObjectMapper
jacksonObjectMapperBuilder
jsonComponentModule
localeCharsetMappingsCustomizer
mappingJackson2HttpMessageConverter
…
…

That’s all about how to print all the beans loaded by Spring boot