[MTOOLCHAINS-60] NullPointerException in ToolchainDiscoverer.getToolchainModel

[jira-importer]

Elliotte Rusty Harold opened MTOOLCHAINS-60 and commented

Ran mvn org.apache.maven.plugins:maven-toolchains-plugin:3.2.0:display-discovered-jdk-toolchains and saw:

{}{}{}[INFO] Found 8 possible jdks: [/opt/homebrew/Cellar/openjdk@17/17.0.13/libexec/openjdk.jdk/Contents/Home, /usr/local/Cellar/openjdk@8/1.8.0+372/libexec/openjdk.jdk/Contents/Home, /Library/Java/JavaVirtualMachines/adoptopenjdk-8.jdk/Contents/Home, /Library/Java/JavaVirtualMachines/temurin-11.jdk/Contents/Home, /Library/Java/JavaVirtualMachines/1.7.0.jdk/Contents/Home, /Library/Java/JavaVirtualMachines/jdk1.8.0_172.jdk/Contents/Home, /Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home, /Library/Java/JavaVirtualMachines/jdk1.7.0_17.jdk/Contents/Home]{}
[WARNING] Error discovering toolchains (enable debug level for more information): java.lang.NullPointerException

---

No further details from MTOOLCHAINS-60

[jira-importer]

Elliotte Rusty Harold commented

Here's the stack trace:

{}{}{}[DEBUG] JDK toolchain discovered at /Library/Java/JavaVirtualMachines/1.7.0.jdk/Contents/Home will be ignored: could not obtain java.version{}
[WARNING] Error discovering toolchains: java.lang.NullPointerException
java.lang.NullPointerException
    at jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0 (Native Method)
    at jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance (NativeConstructorAccessorImpl.java:62)
    at jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance (DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance (Constructor.java:490)
    at java.util.concurrent.ForkJoinTask.getThrowableException (ForkJoinTask.java:603)
    at java.util.concurrent.ForkJoinTask.reportException (ForkJoinTask.java:678)
    at java.util.concurrent.ForkJoinTask.invoke (ForkJoinTask.java:737)
    at java.util.stream.Nodes.collect (Nodes.java:336)
    at java.util.stream.ReferencePipeline.evaluateToNode (ReferencePipeline.java:109)
    at java.util.stream.AbstractPipeline.evaluate (AbstractPipeline.java:545)
    at java.util.stream.SortedOps$OfRef.opEvaluateParallel (SortedOps.java:157)
    at java.util.stream.AbstractPipeline.opEvaluateParallelLazy (AbstractPipeline.java:710)
    at java.util.stream.AbstractPipeline.sourceSpliterator (AbstractPipeline.java:434)
    at java.util.stream.AbstractPipeline.evaluate (AbstractPipeline.java:233)
    at java.util.stream.ReferencePipeline.collect (ReferencePipeline.java:578)
    at org.apache.maven.plugins.toolchain.jdk.ToolchainDiscoverer.discoverToolchains (ToolchainDiscoverer.java:162)
    at org.apache.maven.plugins.toolchain.jdk.DisplayDiscoveredJdkToolchainsMojo.execute (DisplayDiscoveredJdkToolchainsMojo.java:65)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:126)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:328)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:316)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:212)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:174)
    at org.apache.maven.lifecycle.internal.MojoExecutor.access$000 (MojoExecutor.java:75)
    at org.apache.maven.lifecycle.internal.MojoExecutor$1.run (MojoExecutor.java:162)
    at org.apache.maven.plugin.DefaultMojosExecutionStrategy.execute (DefaultMojosExecutionStrategy.java:39)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:159)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:105)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:73)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:53)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:118)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:261)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:173)
    at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:101)
    at org.apache.maven.cli.MavenCli.execute (MavenCli.java:906)
    at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:283)
    at org.apache.maven.cli.MavenCli.main (MavenCli.java:206)
    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:255)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:201)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:361)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:314)
Caused by: java.lang.NullPointerException
    at java.util.concurrent.ConcurrentHashMap.putVal (ConcurrentHashMap.java:1011)
    at java.util.concurrent.ConcurrentHashMap.put (ConcurrentHashMap.java:1006)
    at org.apache.maven.plugins.toolchain.jdk.ToolchainDiscoverer.getToolchainModel (ToolchainDiscoverer.java:241)
    at org.apache.maven.plugins.toolchain.jdk.ToolchainDiscoverer.lambda$discoverToolchains$6 (ToolchainDiscoverer.java:152)
    at java.util.stream.ReferencePipeline$3$1.accept (ReferencePipeline.java:195)
    at java.util.HashMap$KeySpliterator.forEachRemaining (HashMap.java:1621)
    at java.util.stream.AbstractPipeline.copyInto (AbstractPipeline.java:484)
    at java.util.stream.AbstractPipeline.wrapAndCopyInto (AbstractPipeline.java:474)
    at java.util.stream.Nodes$CollectorTask.doLeaf (Nodes.java:2191)
    at java.util.stream.Nodes$CollectorTask.doLeaf (Nodes.java:2157)
    at java.util.stream.AbstractTask.compute (AbstractTask.java:327)
    at java.util.concurrent.CountedCompleter.exec (CountedCompleter.java:746)
    at java.util.concurrent.ForkJoinTask.doExec (ForkJoinTask.java:290)
    at java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec (ForkJoinPool.java:1020)
    at java.util.concurrent.ForkJoinPool.scan (ForkJoinPool.java:1656)
    at java.util.concurrent.ForkJoinPool.runWorker (ForkJoinPool.java:1594)
    at java.util.concurrent.ForkJoinWorkerThread.run (ForkJoinWorkerThread.java:183)
[INFO] Discovered 0 JDK toolchains:

[jira-importer]

Elliotte Rusty Harold commented

This is the code. Probably need another null check before trying to add to the cache since doGetToolchainModel can return null, especially for JDK 1.7 and earlier.

 

    ToolchainModel getToolchainModel(Path jdk) {
        ToolchainModel model = cache.get(jdk);
        if (model == null) {
            model = doGetToolchainModel(jdk);
            cache.put(jdk, model);
            cacheModified = true;
        }
        return model;
{}    }{}{}{}

[Xtrem532]

This is a duplicate of #113