title: Could not publish to the server. java.lang.NullPointerException in Tomcat v8.0 Server
body: <p><a href="https://i.stack.imgur.com/2ZE0v.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2ZE0v.gif" alt="Publishing tomcat v8.0 at localhost error"></a></p>
  
  <p>While Developing Project I got this Error.I used Eclipse Mars and Tomcat v8.0 Server.Actually upto last Night it works good but next morning it shows this error block.Nothing to be displayed in console, Error is just display on pop up window.I didn't get proper solution,So please help me to solve this error</p>
  
  <pre><code>java.lang.NullPointerException
  at org.eclipse.jst.common.internal.modulecore.IgnoreJavaInSourceFolderParticipant.shouldAddExportableFile(IgnoreJavaInSourceFolderParticipant.java:64)
  at org.eclipse.wst.common.componentcore.internal.flat.FlatVirtualComponent.shouldAddComponentFile(FlatVirtualComponent.java:288)
  at org.eclipse.wst.common.componentcore.internal.flat.VirtualComponentFlattenUtility.addFile(VirtualComponentFlattenUtility.java:122)
  at org.eclipse.wst.common.componentcore.internal.flat.VirtualComponentFlattenUtility.addMembersInternal(VirtualComponentFlattenUtility.java:99)
  at org.eclipse.wst.common.componentcore.internal.flat.VirtualComponentFlattenUtility.addMembersInternal(VirtualComponentFlattenUtility.java:96)
  at org.eclipse.wst.common.componentcore.internal.flat.VirtualComponentFlattenUtility.addMembers(VirtualComponentFlattenUtility.java:51)
  at org.eclipse.wst.common.componentcore.internal.flat.FlatVirtualComponent.treeWalk(FlatVirtualComponent.java:230)
  at org.eclipse.wst.common.componentcore.internal.flat.FlatVirtualComponent.cacheResources(FlatVirtualComponent.java:188)
  at org.eclipse.wst.common.componentcore.internal.flat.FlatVirtualComponent.fetchResources(FlatVirtualComponent.java:118)
  at org.eclipse.wst.web.internal.deployables.FlatComponentDeployable.members(FlatComponentDeployable.java:227)
  at org.eclipse.jst.j2ee.internal.deployables.J2EEFlexProjDeployable.members(J2EEFlexProjDeployable.java:267)
  at org.eclipse.wst.server.core.internal.ModulePublishInfo.fillCache(ModulePublishInfo.java:314)
  at org.eclipse.wst.server.core.internal.ModulePublishInfo.getDelta(ModulePublishInfo.java:396)
  at org.eclipse.wst.server.core.internal.ServerPublishInfo.getDelta(ServerPublishInfo.java:366)
  at org.eclipse.wst.server.core.internal.Server.getPublishedResourceDelta(Server.java:1578)
  at org.eclipse.wst.server.core.model.ServerBehaviourDelegate.getPublishedResourceDelta(ServerBehaviourDelegate.java:698)
  at org.eclipse.jst.server.tomcat.core.internal.TomcatServerBehaviour.getPublishedResourceDelta(TomcatServerBehaviour.java:958)
  at org.eclipse.wst.server.core.model.ServerBehaviourDelegate.computeDelta(ServerBehaviourDelegate.java:874)
  at org.eclipse.wst.server.core.model.ServerBehaviourDelegate.publish(ServerBehaviourDelegate.java:909)
  at org.eclipse.wst.server.core.model.ServerBehaviourDelegate.publish(ServerBehaviourDelegate.java:774)
  at org.eclipse.wst.server.core.internal.Server.publishImpl(Server.java:3172)
  at org.eclipse.wst.server.core.internal.Server$PublishJob.run(Server.java:345)
  at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)
  </code></pre>