title: Encountered exception org.apache.catalina.LifecycleException: Failed to start component
body: <p>UPDATE: tomcat and eclipse using different java version. Specifically, eclipse using a newer version of java.</p>
  <p>I'm trying to deploy a .war file to tomcat7 for a webapp, but I can't seem to start it. I can deploy it just fine but then I receive some error messages (JasonTrial was the current .war file I tried to upload):</p>
  <blockquote>
  <p>FAIL - Application at context path /JasonTrial could not be started</p>
  <p>FAIL - Encountered exception org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/JasonTrial]]</p>
  </blockquote>
  <p>I have provided the catalina logs below:</p>
  <pre><code>SEVERE: ContainerBase.addChild: start:
  org.apache.catalina.LifecycleException: Failed to start component[StandardEngine[Catalina].StandardHost[localhost].StandardContext[/JasonTrial]]
  at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
  at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
  at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
  at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
  at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:1095)
  at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:558)
  at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1747)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.lang.reflect.Method.invoke(Method.java:606)
  at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:301)
  at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
  at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
  at org.apache.catalina.manager.ManagerServlet.check(ManagerServlet.java:1516)
  at org.apache.catalina.manager.HTMLManagerServlet.upload(HTMLManagerServlet.java:286)
  at org.apache.catalina.manager.HTMLManagerServlet.doPost(HTMLManagerServlet.java:206)
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
  at org.apache.catalina.filters.CsrfPreventionFilter.doFilter(CsrfPreventionFilter.java:213)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
  at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
  at org.apache.catalina.filters.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:108)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
  at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
  at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
  at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:614)
  at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
  at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
  at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
  at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
  at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
  at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
  at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
  at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
  at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
  at java.lang.Thread.run(Thread.java:745)
  
  
  Caused by: java.lang.UnsupportedClassVersionError: com/example/demo/DemoUI$Servlet : Unsupported major.minor version 52.0 (unable to load class com.example.demo.DemoUI$Servlet)
  at org.apache.catalina.loader.WebappClassLoaderBase.findClassInternal(WebappClassLoaderBase.java:3118)
  at org.apache.catalina.loader.WebappClassLoaderBase.findClass(WebappClassLoaderBase.java:1342)
  at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1823)
  at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1703)
  at org.atmosphere.util.IOUtils.isAtmosphere(IOUtils.java:349)
  at org.atmosphere.cpr.AtmosphereInitializer.onStartup(AtmosphereInitializer.java:66)
  at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5506)
  at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
  ... 44 more
  
  Jan 22, 2016 4:58:44 AM org.apache.catalina.startup.HostConfig deployWAR
  SEVERE: Error deploying web application archive /var/lib/tomcat7/webapps/JasonTrial.war
  java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/JasonTrial]]
  at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:905)
  at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
  at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
  at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:1095)
  at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:558)
  at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1747)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.lang.reflect.Method.invoke(Method.java:606)
  at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:301)
  at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
  at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
  at org.apache.catalina.manager.ManagerServlet.check(ManagerServlet.java:1516)
  at org.apache.catalina.manager.HTMLManagerServlet.upload(HTMLManagerServlet.java:286)
  at org.apache.catalina.manager.HTMLManagerServlet.doPost(HTMLManagerServlet.java:206)
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
  at org.apache.catalina.filters.CsrfPreventionFilter.doFilter(CsrfPreventionFilter.java:213)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
  at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
  at org.apache.catalina.filters.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:108)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
  at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
  at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
  at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:614)
  at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
  at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
  at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
  at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
  at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
  at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
  at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
  at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
  at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
  at java.lang.Thread.run(Thread.java:745)
  </code></pre>
  <p>Most stackoverflow questions have pointed to a problem with an IDE, but I'm using my own tomcat server on AWS so I'm not sure where to look for the problem. Otherwise, they have pointed to a problem in the web.xml but I don't think I have any problems there.</p>