[MJAVADOC-504] NullPointerException in JavadocUtil.getJavaHome() when JAVA_HOME isn't set

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0
• Fix Version/s: 3.0.1
• Environment: Debian, OpenJDK 8
• Assignee: Robert Scholte
• Reporter: Emmanuel Bourg
• Created: 13/Dec/17 08:29
• Updated: 05/Jan/18 20:32
• Resolved: 05/Jan/18 20:16

Description

Hi,

After upgrading to maven-javadoc-plugin I noticed a NullPointerException in JavadocUtil.getJavaHome() when the JAVA_HOME environment variable isn't set:

java.lang.NullPointerException
    at java.io.File.<init> (File.java:277)
    at org.apache.maven.plugins.javadoc.JavadocUtil.getJavaHome (JavadocUtil.java:1302)
    at org.apache.maven.plugins.javadoc.JavadocUtil.invokeMaven (JavadocUtil.java:941)
    at org.apache.maven.plugins.javadoc.AbstractJavadocMojo.getModulesLinks (AbstractJavadocMojo.java:5640)
    at org.apache.maven.plugins.javadoc.AbstractJavadocMojo.addLinkofflineArguments (AbstractJavadocMojo.java:4046)
    at org.apache.maven.plugins.javadoc.AbstractJavadocMojo.addStandardDocletOptions (AbstractJavadocMojo.java:4936)
    at org.apache.maven.plugins.javadoc.AbstractJavadocMojo.executeReport (AbstractJavadocMojo.java:2074)
    at org.apache.maven.plugins.javadoc.JavadocReport.generate (JavadocReport.java:134)
    at org.apache.maven.plugins.javadoc.JavadocReport.doExecute (JavadocReport.java:329)
    at org.apache.maven.plugins.javadoc.AbstractJavadocMojo.execute (AbstractJavadocMojo.java:1909)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:134)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:208)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:154)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:146)
    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:51)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:128)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:309)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:194)
    at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:107)
    at org.apache.maven.cli.MavenCli.execute (MavenCli.java:993)
    at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:345)
    at org.apache.maven.cli.MavenCli.main (MavenCli.java:191)
    at org.apache.maven.cli.MavenCli.main (MavenCli.java:180)

This error doesn't occur with the version 3.0.0-M1 or when JAVA_HOME is set. It can be reproduced on the byte-buddy project:

git clone https://github.com/raphw/byte-buddy
cd byte-buddy
git checkout byte-buddy-1.7.9
mvn org.apache.maven.plugins:maven-javadoc-plugin:3.0.0:javadoc