How to get all loaded Beans in SpringBoot

In this tutorial, we will show how to find out all the Beans that are loaded by a Spring Boot Application class and their class type information.

Using ApplicationContext to retrieve all loaded Beans

The ApplicationContext is the main interface of a Spring application when it is required to retrieve configuration information to the application. It is read-only at run time, but can be reloaded if necessary and supported by the application. In order to do that, the following methods can be used:

1) ApplicationContext.getBeanDefinitionNames() to find the name of all loaded beans
2) ApplicationContext.getBean(beanName) to get bean including its runtime type information.

Here is an expanded version of our JPA basic application (See Using SpringBoot with JPA tutorial ) which uses the ApplicationContext to print out the Bean information:

package com.example.samplewebapp;
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;
import org.springframework.context.annotation.Bean;
import java.util.Arrays;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@SpringBootApplication public class DemoApplication {
  private static final Logger log = LoggerFactory.getLogger(DemoApplication.class);
  @Autowired private ApplicationContext appContext;
  public void dumpBeans() {
    String[] beans = appContext.getBeanDefinitionNames();
    Arrays.sort(beans);
    for (String bean: beans) {
      System.out.println(bean + " of Type :: " + appContext.getBean(bean).getClass());
    }
  }
  public static void main(String[] args) {
    SpringApplication.run(DemoApplication.class, args);
  }
  @Bean public CommandLineRunner demo(PersonRepository repository) {
    return (args) -> { // save a couple of persons 			
      repository.save(new Person("Jack", "Smith"));repository.save(new Person("Joe", "Black"));repository.save(new Person("Martin", "Bauer"));
      // fetch all persons 			
      log.info("Persons found with findAll():");log.info("-------------------------------");
      for (Person person: repository.findAll()) {
        log.info(person.toString());
      }
      log.info("");
      // fetch an individual person by ID 			
      repository.findById(1 L).ifPresent(person -> {
        log.info("Person found with findById(1L):");log.info("--------------------------------");log.info(person.toString());log.info("");
      });
      // fetch persons by last name
      log.info("Person found with findBySurname('Black'):");log.info("--------------------------------------------");repository.findBySurname("Black").forEach(smith -> {
        log.info(smith.toString());
      });log.info("");dumpBeans();
    };
  }
}

Running above application will print bean names and type information in console like below: