How do I enumerate all the BeanFactories in Spring? - spring

Question

Is there a way to discover all the BeanFactories defined by Spring programmatically. I want to create a status debug page which prints out the names and class types of every bean in the spring application context, however I don't know how to obtain a list of all the ApplicationContexts.

Answer 1

You can wire a BeanFactoryPostProcessor with your ApplicationContext that will allow you to traverse the BeanDefinition's of a passed ConfigurableListableBeanFactory which will represent all of the beans from your ApplicationContext.
With this instance of ConfigurableListableBeanFactory, you can find all beans of a type (getBeansOfType()), or all beans with a given annotation (getBeansWithAnnotation()), among other things.

Answer 2

You can use the ApplicationContext aware to do this.
#Component
public class PrintSpringBeansInContext implements ApplicationContextAware
{
private ApplicationContext applicationContext;
#Override
public void setApplicationContext(ApplicationContext applicationContext)
throws BeansException
{
this.applicationContext = applicationContext;
}
public void print()
{
String[] beanNames = this.applicationContext.getBeanDefinitionNames();
StringBuilder printBuilder = new StringBuilder("Spring Beans In Context: ");;
for(String beanName : beanNames)
{
printBuilder.append("\n");
printBuilder.append(" Bean Name: ");
printBuilder.append(beanName);
printBuilder.append(" Bean Class: ");
printBuilder.append(this.applicationContext.getBean(beanName).getClass());
}
System.out.println(printBuilder.toString());
}
}
You can test this
#ContextConfiguration(locations={"classpath:context.xml"})
#RunWith(SpringJUnit4ClassRunner.class)
public class PrintContextTest
{
#Autowired
private PrintSpringBeansInContext service;
#Test
public void printBeans()
{
Assert.assertNotNull(service);
service.print();
}
}

Answer 3

Code below is a Spring listener which can be registered with the main spring.xml file for the web application, it builds a map of all the child application contexts and exposes this map as a property. The class below can be injected into any spring bean that needs it using #Autowired.
import java.util.Hashtable;
import java.util.Map;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ApplicationContextEvent;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.context.event.ContextStartedEvent;
public class ContextsApplicationListener implements ApplicationListener<ApplicationContextEvent> {
private Map<String,ApplicationContext> contextMap = new Hashtable<String,ApplicationContext>();
#Override
public void onApplicationEvent(ApplicationContextEvent event) {
if( event instanceof ContextStartedEvent || event instanceof ContextRefreshedEvent){
this.getContextMap().put(event.getApplicationContext().getDisplayName(), event.getApplicationContext());
}
}
public Map<String,ApplicationContext> getContextMap() {
return contextMap;
}
}
enter code here