title: Spring MVC on GAE: 500 Internal Server Error (Intellij)
body: <p>I'm getting these errors after putting on code for Spring MVC. It's a maven project with Google App Engine running on Intellij IDEA. Before I started using Spring MVC framework and adding in the .xml files for spring-servlet, everything was running fine. Can anyone help me to figure out what this error means and how to fix it? Thanks in advance.</p>
  
  <pre><code>bad runtime process port ['']
  
  at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
  at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
  at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
  at org.mortbay.jetty.Server.doStart(Server.java:224)
  at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
  at com.google.appengine.tools.development.JettyContainerService.startContainer(JettyContainerService.java:268)
  at com.google.appengine.tools.development.AbstractContainerService.startup(AbstractContainerService.java:284)
  at com.google.appengine.tools.development.AutomaticInstanceHolder.startUp(AutomaticInstanceHolder.java:26)
  at com.google.appengine.tools.development.AbstractModule.startup(AbstractModule.java:87)
  at com.google.appengine.tools.development.Modules.startup(Modules.java:105)
  at com.google.appengine.tools.development.devappserver2.DevAppServer2Impl.doStart(DevAppServer2Impl.java:250)
  at ...
  
      Feb 10, 2017 9:26:25 PM com.google.appengine.tools.development.devappserver2.RemoteApiDelegate log
  SEVERE: [1486761985829000] javax.servlet.ServletContext log: unavailable
  javax.servlet.UnavailableException: org.springframework.web.servlet.DispatcherServlet
      at org.mortbay.jetty.servlet.Holder.doStart(Holder.java:79)
      at org.mortbay.jetty.servlet.ServletHolder.doStart(ServletHolder.java:242)
      at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
      at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:685)
      at org.mortbay.jetty.servlet.Context.startContext(Context.java:140)
      at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)
      at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517)
      at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467)
  ...
  
  Feb 10, 2017 9:26:25 PM com.google.apphosting.utils.jetty.JettyLogger warn
  WARNING: failed spring-web: java.lang.NullPointerException
  Feb 10, 2017 9:26:25 PM com.google.apphosting.utils.jetty.JettyLogger warn
  WARNING: Failed startup of context com.google.appengine.tools.development.DevAppEngineWebAppContext@fdefd3f{/,D:\CSE308Project\teambuildingexercise\todolist\target\todolist-1.0-SNAPSHOT}
  java.lang.NullPointerException
      at java.lang.Class.isAssignableFrom(Native Method)
      at org.mortbay.jetty.servlet.ServletHolder.doStart(ServletHolder.java:256)
      at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
      at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:685)
      at org.mortbay.jetty.servlet.Context.startContext(Context.java:140)
      at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)
      at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517)
  ...
  
  Feb 10, 2017 9:26:25 PM com.google.apphosting.utils.jetty.JettyLogger info
  INFO: Started SelectChannelConnector@localhost:54107
  Feb 10, 2017 9:26:25 PM com.google.appengine.tools.development.AbstractModule startup
  INFO: Module instance default is running at http://localhost:54107/
  Feb 10, 2017 9:26:25 PM com.google.appengine.tools.development.AbstractModule startup
  INFO: The admin console is running at http://localhost:54107/_ah/admin
  Feb 10, 2017 4:26:25 PM com.google.appengine.tools.development.devappserver2.DevAppServer2Impl doStart
  INFO: Dev App Server is now running
  </code></pre>
  
  <p>If anymore parts of my project is needed, please let me know and i'll post more.
  (Already running on jdk1.7, still get the same error.)</p>