NPE on site generation

[hohwille]

In my project site-generation fails if license-maven-plugin:2.0.0 is configured.

...
      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>license-maven-plugin</artifactId>
        <reportSets>
          <reportSet>
            <reports>
              <report>third-party-report</report>
              <report>aggregate-third-party-report</report>
            </reports>
          </reportSet>
        </reportSets>
      </plugin>
     </plugins>
  </reporting>

Stacktrace:

Caused by: org.apache.maven.plugin.PluginExecutionException: Execution default-site of goal org.apache.maven.plugins:maven-site-plugin:3.7.1:site failed.
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:148)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:210)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:156)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:148)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:81)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:56)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:128)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:305)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:192)
    at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:105)
    at org.apache.maven.cli.MavenCli.execute (MavenCli.java:956)
    at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:288)
    at org.apache.maven.cli.MavenCli.main (MavenCli.java:192)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
    at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke (Method.java:566)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:282)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:225)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:406)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:347)
Caused by: java.lang.NullPointerException
    at java.util.HashSet.<init> (HashSet.java:119)
    at org.codehaus.mojo.license.api.ResolvedProjectDependencies.<init> (ResolvedProjectDependencies.java:50)
    at org.codehaus.mojo.license.AbstractThirdPartyReportMojo.createThirdPartyDetails (AbstractThirdPartyReportMojo.java:559)
    at org.codehaus.mojo.license.AggregatorThirdPartyReportMojo.createThirdPartyDetails (AggregatorThirdPartyReportMojo.java:127)
    at org.codehaus.mojo.license.AbstractThirdPartyReportMojo.executeReport (AbstractThirdPartyReportMojo.java:420)
    at org.apache.maven.reporting.AbstractMavenReport.generate (AbstractMavenReport.java:251)
    at org.apache.maven.plugins.site.render.ReportDocumentRenderer.renderDocument (ReportDocumentRenderer.java:230)
    at org.apache.maven.doxia.siterenderer.DefaultSiteRenderer.render (DefaultSiteRenderer.java:349)
    at org.apache.maven.plugins.site.render.SiteMojo.renderLocale (SiteMojo.java:198)
    at org.apache.maven.plugins.site.render.SiteMojo.execute (SiteMojo.java:147)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:137)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:210)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:156)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:148)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:81)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:56)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:128)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:305)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:192)
    at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:105)
    at org.apache.maven.cli.MavenCli.execute (MavenCli.java:956)
    at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:288)
    at org.apache.maven.cli.MavenCli.main (MavenCli.java:192)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
    at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke (Method.java:566)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:282)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:225)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:406)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:347)

[hohwille]

NPE happens here:

https://github.com/mojohaus/license-maven-plugin/blob/d47178b5c58d74714bda202e358bf7927ec67788/src/main/java/org/codehaus/mojo/license/api/ResolvedProjectDependencies.java#L50

So the provided Set (directDependencies) to make immutable is already null.

[hohwille]

at org.codehaus.mojo.license.AbstractThirdPartyReportMojo.createThirdPartyDetails (AbstractThirdPartyReportMojo.java:559)

According to your tag license-maven-plugin-2.0.0 this is here:

https://github.com/mojohaus/license-maven-plugin/blob/license-maven-plugin-2.0.0/src/main/java/org/codehaus/mojo/license/AbstractThirdPartyReportMojo.java#L559

[hohwille]

So project.getDependencyArtifacts() was null in my case? Strange...

[hohwille]

Breaking the entire site build with an exception is always bad. However, just tested to downgrade to version 1.20 and the problem is gone. So maybe easy to fix and ship a 2.x.y version.

[planetf1]

I was just about to raise the same issue! Getting exactly the same when trying to build the third party aggregate report - NPE.

[planetf1]

can confirm 1.20 does not exhibit this problem

[Tibor17]

@ppalaga This trivial NPE should be fixed asap. It is very annoying to see a broken build because of NPE!