[MECLIPSE-738] NullPointerException in LinkedResource if <locationURI> is present in .project

• Type: Bug
• Status: Closed
• Priority: Trivial
• Resolution: Fixed
• Affects Version/s: 2.9
• Fix Version/s: 2.10
• Assignee: Andreas Gudian
• Reporter: Martin Böhm
• Created: 13/Feb/13 11:56
• Updated: 25/Mar/15 13:19
• Resolved: 25/Mar/15 13:19

Description

I get a reproducable NullPointerException if I call eclipse:eclipse on a project that always has a .project-file that contains links with <locationURI>-Tags.

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-eclipse-plugin:2.9:eclipse (default-cli) on project linkedResourceProblem: Execution def
ault-cli of goal org.apache.maven.plugins:maven-eclipse-plugin:2.9:eclipse failed. NullPointerException -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-eclipse-plugin:2.9:eclipse (default-cli)
 on project linkedResourceProblem: Execution default-cli of goal org.apache.maven.plugins:maven-eclipse-plugin:2.9:eclipse failed.
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:225)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:320)
        at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
        at org.apache.maven.cli.MavenCli.execute(MavenCli.java:537)
        at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
        at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
        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:601)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
        at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
        at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)
Caused by: org.apache.maven.plugin.PluginExecutionException: Execution default-cli of goal org.apache.maven.plugins:maven-eclipse-plugin:2.9:eclipse f
ailed.
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:110)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
        ... 19 more
Caused by: java.lang.NullPointerException
        at org.apache.maven.plugin.eclipse.LinkedResource.<init>(LinkedResource.java:131)
        at org.apache.maven.plugin.eclipse.writers.EclipseProjectWriter.write(EclipseProjectWriter.java:154)
        at org.apache.maven.plugin.eclipse.EclipsePlugin.writeConfiguration(EclipsePlugin.java:1232)
        at org.apache.maven.plugin.ide.AbstractIdeSupportMojo.execute(AbstractIdeSupportMojo.java:511)
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
        ... 20 more

If I change the present <locationURI> to <location> in .project and call eclipse:eclipse I won't get the error. Also if I call eclipse:clean before calling eclipse:eclipse the .project file of course gets cleaned and will be created new, so temporary links get lost unfortunately.

I suppose it has to do with the following lines in org.apache.maven.plugin.eclipse.LinkedResource and how the locationNode is retrieved.

119 	Xpp3Dom locationNode = node.getChild( "location" );
120 	Xpp3Dom locationURINode = node.getChild( "locationURI" );

Possible workarounds:

• Call eclipse:clean before and recreate temporary links again.
• Replace all <locationURI> with <location> before calling eclipse:eclipse to preserve temporary links.