title: Failed to start bean 'subProtocolWebSocketHandler'; nested exception is java.lang.IllegalArgumentException: No handlers
body: <pre><code>Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
  2018-07-25 09:17:32.977 ERROR 8176 --- [           main] o.s.boot.SpringApplication               : Application run failed
  
  org.springframework.context.ApplicationContextException: Failed to start bean 'subProtocolWebSocketHandler'; nested exception is java.lang.IllegalArgumentException: No handlers
      at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:184) ~[spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE]
      at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:173) ~[spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE]
      at org.springframework.context.support.DefaultLifecycleProcessor.access$200(DefaultLifecycleProcessor.java:52) ~[spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE]
      at org.springframework.context.support.DefaultLifecycleProcessor$LifecycleGroup.start(DefaultLifecycleProcessor.java:356) ~[spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE]
      at org.springframework.context.support.DefaultLifecycleProcessor.startBeans(DefaultLifecycleProcessor.java:157) ~[spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE]
      at org.springframework.context.support.DefaultLifecycleProcessor.onRefresh(DefaultLifecycleProcessor.java:121) ~[spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE]
      at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:885) ~[spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE]
      at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.finishRefresh(ServletWebServerApplicationContext.java:161) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
      at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:553) ~[spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE]
      at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
      at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
      at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:395) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
      at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
      at org.springframework.boot.SpringApplication.run(SpringApplication.java:1255) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
      at org.springframework.boot.SpringApplication.run(SpringApplication.java:1243) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
      at com.rajan.WebsocketDemoApplication.main(WebsocketDemoApplication.java:10) [classes/:na]
  Caused by: java.lang.IllegalArgumentException: No handlers
      at org.springframework.util.Assert.isTrue(Assert.java:116) ~[spring-core-5.0.7.RELEASE.jar:5.0.7.RELEASE]
      at org.springframework.web.socket.messaging.SubProtocolWebSocketHandler.start(SubProtocolWebSocketHandler.java:247) ~[spring-websocket-5.0.7.RELEASE.jar:5.0.7.RELEASE]
      at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:181) ~[spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE]
      ... 15 common frames omitted
  </code></pre>