Spring 4 @AutoWired Failed

Question

I am trying websocket sample and here I am getting error.

`@Configuration
@EnableWebSocketMessageBroker
@EnableScheduling
@Component
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {


      @Autowired
      private SimpMessagingTemplate template;

      private TaskScheduler scheduler = new ConcurrentTaskScheduler();


    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {

        registry.addEndpoint("/simplemessages").withSockJS();
    }

    /**
     * Configure message broker options.
     */
     @Override
    public void configureMessageBroker(MessageBrokerRegistry config) {

        config.enableSimpleBroker("/topic/", "/queue/");
        config.setApplicationDestinationPrefixes("/app");
    }


    @PostConstruct
    private void broadcastTimePeriodically() {
      scheduler.scheduleAtFixedRate(new Runnable() {
         public void run() {

             template.convertAndSend("/topic/simplemessagesresponse", "Updated text "+new Date());


        }
      }, 1000);
    }

    @Override
    public void configureClientInboundChannel(ChannelRegistration registration) {

    }

   @Override
   public void configureClientOutboundChannel(ChannelRegistration registration) {
      registration.taskExecutor().corePoolSize(4).maxPoolSize(10);
  }

    @Override
    public boolean configureMessageConverters(List<MessageConverter> arg0) {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public void configureWebSocketTransport(WebSocketTransportRegistration arg0) {


    }

}  

`

Here is my Spring context xml

`

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/mvc
                        http://www.springframework.org/schema/mvc/spring-mvc.xsd                        
                        http://www.springframework.org/schema/beans                     
                        http://www.springframework.org/schema/beans/spring-beans.xsd
                        http://www.springframework.org/schema/context
                        http://www.springframework.org/schema/context/spring-context.xsd">



     <context:component-scan base-package="com.action" />

    <context:annotation-config/>
    <!-- <annotation-driven /> -->


</beans>

`

 SEVERE: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'webSocketConfig': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.springframework.messaging.simp.SimpMessagingTemplate com.action.WebSocketConfig.template; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'brokerMessagingTemplate' defined in class path resource [org/springframework/web/socket/config/annotation/DelegatingWebSocketMessageBrokerConfiguration.class]: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.springframework.messaging.simp.SimpMessagingTemplate org.springframework.messaging.simp.config.AbstractMessageBrokerConfiguration.brokerMessagingTemplate()] threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'brokerMessageConverter' defined in class path resource [org/springframework/web/socket/config/annotation/DelegatingWebSocketMessageBrokerConfiguration.class]: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.springframework.messaging.converter.CompositeMessageConverter org.springframework.messaging.simp.config.AbstractMessageBrokerConfiguration.brokerMessageConverter()] threw exception; nested exception is java.lang.IllegalArgumentException: Converters must not be empty
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:326)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1204)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:538)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)

Any one can let me know why ?

Answer 1

Your issue is here:

@Override
public boolean configureMessageConverters(List<MessageConverter> arg0) {
       // TODO Auto-generated method stub
       return false;
}

I understand that it is an auto-generated code, but in my test-case with your sample I get this StackTrace:

Caused by: java.lang.IllegalArgumentException: Converters must not be empty
    at org.springframework.util.Assert.notEmpty(Assert.java:268)
    at org.springframework.messaging.converter.CompositeMessageConverter.<init>(CompositeMessageConverter.java:43)
    at org.springframework.messaging.simp.config.AbstractMessageBrokerConfiguration.brokerMessageConverter(AbstractMessageBrokerConfiguration.java:266)

That means: or you must return true from that method to register default converters or should add some your own converters to that List<MessageConverter>.

When I change it to return true everything works well.