[MWAR-439] WAR Plugin 3.3.1 hits NPE when exploding if maven session start time is null

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.3.1
• Fix Version/s: 3.3.2
• Environment: Windows 10 ; Eclipse Version: 20200910-1200 ; m2e Version: 1.16.1.20200710-1008
• Assignee: Herve Boutemy
• Reporter: Ben DeLillo
• Created: 03/Nov/20 16:11
• Updated: 05/Sep/21 08:57
• Resolved: 05/Sep/21 08:57

Description

I don't have a distributable repro case, but I can say that in my multi-module project, when the exploded goal is invoked by eclipse and m2e the following error occurs:

Execution default of goal org.apache.maven.plugins:maven-war-plugin:3.3.1:exploded failed. (org.apache.maven.plugins:maven-war-plugin:3.3.1:exploded:default:process-resources) 

The stack trace for this error is

org.apache.maven.plugin.PluginExecutionException: Execution default of goal org.apache.maven.plugins:maven-war-plugin:3.3.1:exploded failed. at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:148) at org.eclipse.m2e.core.internal.embedder.MavenImpl.execute(MavenImpl.java:332) at org.eclipse.m2e.core.internal.embedder.MavenImpl.lambda$8(MavenImpl.java:1380) at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.executeBare(MavenExecutionContext.java:179) at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:114) at org.eclipse.m2e.core.internal.embedder.MavenImpl.execute(MavenImpl.java:1379) at org.eclipse.m2e.core.project.configurator.MojoExecutionBuildParticipant.build(MojoExecutionBuildParticipant.java:54) at org.eclipse.m2e.core.internal.builder.MavenBuilderImpl.build(MavenBuilderImpl.java:135) at org.eclipse.m2e.core.internal.builder.MavenBuilder$1.method(MavenBuilder.java:169) at org.eclipse.m2e.core.internal.builder.MavenBuilder$1.method(MavenBuilder.java:1) at org.eclipse.m2e.core.internal.builder.MavenBuilder$BuildMethod.lambda$1(MavenBuilder.java:114) at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.executeBare(MavenExecutionContext.java:179) at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:114) at org.eclipse.m2e.core.internal.builder.MavenBuilder$BuildMethod.lambda$0(MavenBuilder.java:105) at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.executeBare(MavenExecutionContext.java:179) at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:153) at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:101) at org.eclipse.m2e.core.internal.builder.MavenBuilder$BuildMethod.execute(MavenBuilder.java:88) at org.eclipse.m2e.core.internal.builder.MavenBuilder.build(MavenBuilder.java:197) at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:832) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:45) at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:220) at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:263) at org.eclipse.core.internal.events.BuildManager$1.run(BuildManager.java:316) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:45) at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:319) at org.eclipse.core.internal.events.BuildManager.basicBuildLoop(BuildManager.java:371) at org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:392) at org.eclipse.core.internal.resources.Workspace.buildInternal(Workspace.java:515) at org.eclipse.core.internal.resources.Workspace.build(Workspace.java:405) at org.eclipse.ui.actions.GlobalBuildAction$1.run(GlobalBuildAction.java:180) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63) Caused by: java.lang.NullPointerException at org.apache.maven.plugins.war.AbstractWarMojo$DefaultWarPackagingContext$1.visitFile(AbstractWarMojo.java:661) at org.apache.maven.plugins.war.AbstractWarMojo$DefaultWarPackagingContext$1.visitFile(AbstractWarMojo.java:656) at java.base/java.nio.file.Files.walkFileTree(Files.java:2804) at java.base/java.nio.file.Files.walkFileTree(Files.java:2876) at org.apache.maven.plugins.war.AbstractWarMojo$DefaultWarPackagingContext.<init>(AbstractWarMojo.java:655) at org.apache.maven.plugins.war.AbstractWarMojo.buildWebapp(AbstractWarMojo.java:520) at org.apache.maven.plugins.war.AbstractWarMojo.buildExplodedWebapp(AbstractWarMojo.java:453) at org.apache.maven.plugins.war.WarExplodedMojo.execute(WarExplodedMojo.java:43) at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:137) ... 31 more pom.xml /my-legacy-app line 1753 Maven Build Problem

I've debugged into AbstractWarMojo.visitFile, and on line 661 session.getStartTime() is null, so the call to getTime() throws an NPE. Attempting to track down why the start time is null led me to MavenImpl, at which point I've gotten a bit stuck trying to further track down the issue. I think it was pointing to something in MavenExecutionContext, but I'm not entirely sure.

The check against getStartTime was introduced in 3.3.1 so switching to 3.3.0 unblocks me for now.

 

Issue Links

• relates to: MWAR-433 Maven WAR plugin is deleting files generated by other plugins after upgrading to 3.3.0