I want to connect to the Sonic Broker Topic and listen to any incoming XML message. I did something like below;
Application.java
@SpringBootApplication @ComponentScan({"com.mainpack", "com.msgpack.jms"}) @EnableJms public class Application extends SpringBootServletInitializer { @Autowired private JmsTopicListener jmsTopicListener; @Override protected SpringApplicationBuilder configure(SpringApplicationBuilder application) { return application.sources(Application.class); } @Override public void onStartup(final ServletContext servletContext) throws ServletException { try { LogService.info(Application.class.getName(), "Starting Service..."); super.onStartup(servletContext); jmsTopicListener.listenMessage(); LogService.info(Application.class.getName(), "Service Started"); } catch (Exception ex) { LogService.error(this.getClass().getName(), ex); } } public static void main(String[] args) { ApplicationContext context = SpringApplication.run(Application.class, args); LogService.info(Application.class.getName(), "Service Started..."); } }
JmsTopicListener.java
@Component public class JmsTopicListener { @Autowired private ApplicationProperties properties; @Autowired private MsgListener msgListener; public void listenMessage() { TopicConnectionFactory factory; TopicConnection connection = null; LogService.info(this.getClass().getName(), "Registering Broker Connection"); try { factory = new progress.message.jclient.TopicConnectionFactory(properties.getBrokerURL()); connection = factory.createTopicConnection(properties.getUserName(), properties.getPass()); javax.jms.TopicSession subSession = (TopicSession) connection.createTopicSession(false, Session.AUTO_ACKNOWLEDGE); javax.jms.Topic topic = subSession.createTopic(properties.getTopicName()); MessageConsumer subscriber = subSession.createSubscriber(topic); subscriber.setMessageListener(msgListener); connection.start(); LogService.info(this.getClass().getName(), "Broker connected"); } catch (Exception ex) { LogService.error(this.getClass().getName(), ex); } } }
Msglistist.java
@Component public class MsgListener implements MessageListener { @Override public void onMessage(Message msg) { if (msg instanceof XMLMessage) { try { XMLMessage m = (XMLMessage) msg; if (m.getText().contains("Applications")) { LogService.info(this.getClass().getName(), "Recieved A Applications Message"); } else { LogService.info(this.getClass().getName(), "Recieved Message Does not contain Applications Tag"); } } catch (Exception ex) { LogService.info(this.getClass().getName(), "Exception: " + ex.getMessage()); } } } }
When I run this code, I get nullPointer in the jmsTopicListener.listenMessage() in Application.java .
What mistake did I make here? Is there a way I can improve this (I mean that the work is done in less code)?
NOTE. com.mainpack has classes Application.java and ApplicationProp.java com.msgpack.jms have JmsTopicListener.java and MsgListner.java
Error from the registrar:
ERROR [2015-07-14 14:34:52] [com.mainpack.Application] [localhost-startStop-1] - [Exception: ]java.lang.NullPointerException at com.mainpack.Application.onStartup(Application.java:33) at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:175) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5156) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:725) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:701) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:717) at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:945) at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1768) at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) at java.util.concurrent.FutureTask.run(Unknown Source) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source)