I was following https://developers.google.com/appengine/docs/java/webtoolsplatform#dynamic_web_project and got an error “Failed while installing Dynamic Web Module 2.5” at the very last step.
I had installed the Web Tools Platform by following these instructions: http://wiki.eclipse.org/WTP_FAQ#How_do_I_install_WTP.3F
That entailed installing these components from the Web, XML, Java EE and OSGi Enterprise Development:
Eclipse Java EE Developer Tool JST Server Adapters Extensions
I was following https://developers.google.com/appengine/docs/java/webtoolsplatform#dynamic_web_project and got an error “Failed while installing Dynamic Web Module 2.5” at the very last step.
I checked in my Eclipse error log (.metadata/.log) and I found these stack traces:
!ENTRY org.eclipse.jst.j2ee 4 0 2014-06-25 17:05:18.727 !MESSAGE No IModelProvider exists for project P/MyFrontendProject of version: Dynamic Web Module 2.5 !STACK 0 java.lang.NullPointerException: No IModelProvider exists for project P/MyFrontendProject of version: Dynamic Web Module 2.5 at org.eclipse.jst.j2ee.model.ModelProviderManager.getModelProvider(ModelProviderManager.java:101) at org.eclipse.jst.j2ee.web.project.facet.WebFacetInstallDelegate.populateDefaultContent(WebFacetInstallDelegate.java:284) at org.eclipse.jst.j2ee.web.project.facet.WebFacetInstallDelegate.createWeb25DeploymentDescriptor(WebFacetInstallDelegate.java:274) at org.eclipse.jst.j2ee.web.project.facet.WebFacetInstallDelegate.execute(WebFacetInstallDelegate.java:128) at org.eclipse.wst.common.project.facet.core.internal.FacetedProject.callDelegate(FacetedProject.java:1477) at org.eclipse.wst.common.project.facet.core.internal.FacetedProject.modifyInternal(FacetedProject.java:441) at org.eclipse.wst.common.project.facet.core.internal.FacetedProject.mergeChangesInternal(FacetedProject.java:1181) at org.eclipse.wst.common.project.facet.core.internal.FacetedProject.access$2(FacetedProject.java:1117) at org.eclipse.wst.common.project.facet.core.internal.FacetedProject$5.run(FacetedProject.java:1099) at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2345) at org.eclipse.wst.common.project.facet.core.internal.FacetedProject.mergeChanges(FacetedProject.java:1109) at org.eclipse.wst.common.project.facet.core.internal.FacetedProjectWorkingCopy.commitChanges(FacetedProjectWorkingCopy.java:2020) at org.eclipse.wst.common.project.facet.ui.ModifyFacetedProjectWizard.performFinish(ModifyFacetedProjectWizard.java:400) at org.eclipse.wst.web.ui.internal.wizards.NewProjectDataModelFacetWizard.performFinish(NewProjectDataModelFacetWizard.java:282) at org.eclipse.wst.common.project.facet.ui.ModifyFacetedProjectWizard$3.run(ModifyFacetedProjectWizard.java:331) at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2345) at org.eclipse.wst.common.project.facet.ui.ModifyFacetedProjectWizard$4.run(ModifyFacetedProjectWizard.java:345) at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:121)
!ENTRY org.eclipse.wst.common.project.facet.core 4 0 2014-06-25 17:05:18.934 !MESSAGE Failed while installing Dynamic Web Module 2.5. !STACK 0 java.lang.NullPointerException at org.eclipse.jst.j2ee.web.project.facet.WebFacetInstallDelegate.populateDefaultContent(WebFacetInstallDelegate.java:311) at org.eclipse.jst.j2ee.web.project.facet.WebFacetInstallDelegate.createWeb25DeploymentDescriptor(WebFacetInstallDelegate.java:274) at org.eclipse.jst.j2ee.web.project.facet.WebFacetInstallDelegate.execute(WebFacetInstallDelegate.java:128) at org.eclipse.wst.common.project.facet.core.internal.FacetedProject.callDelegate(FacetedProject.java:1477) at org.eclipse.wst.common.project.facet.core.internal.FacetedProject.modifyInternal(FacetedProject.java:441) at org.eclipse.wst.common.project.facet.core.internal.FacetedProject.mergeChangesInternal(FacetedProject.java:1181) at org.eclipse.wst.common.project.facet.core.internal.FacetedProject.access$2(FacetedProject.java:1117) at org.eclipse.wst.common.project.facet.core.internal.FacetedProject$5.run(FacetedProject.java:1099) at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2345) at org.eclipse.wst.common.project.facet.core.internal.FacetedProject.mergeChanges(FacetedProject.java:1109) at org.eclipse.wst.common.project.facet.core.internal.FacetedProjectWorkingCopy.commitChanges(FacetedProjectWorkingCopy.java:2020) at org.eclipse.wst.common.project.facet.ui.ModifyFacetedProjectWizard.performFinish(ModifyFacetedProjectWizard.java:400) at org.eclipse.wst.web.ui.internal.wizards.NewProjectDataModelFacetWizard.performFinish(NewProjectDataModelFacetWizard.java:282) at org.eclipse.wst.common.project.facet.ui.ModifyFacetedProjectWizard$3.run(ModifyFacetedProjectWizard.java:331) at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2345) at org.eclipse.wst.common.project.facet.ui.ModifyFacetedProjectWizard$4.run(ModifyFacetedProjectWizard.java:345) at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:121)
The 2 features recommended by http://wiki.eclipse.org/WTP_FAQ#How_do_I_install_WTP.3F aren't enough to complete the instructions at https://developers.google.com/appengine/docs/java/webtoolsplatform#dynamic_web_project:
Eclipse Java EE Developer Tools JST Server Adapters Extensions
I found that I also had to add this one:
Eclipse Java Web Developer Tools