javadoc executable not found with maven if even $JAVA_HOME seems correctly set

0
votes

I am building the distribution package to install wikidata-query-rdf / Blazegraph to be use with my Wikibase installation.

I am struggling to fix a few Java-related issues when I do sudo ./mvnw package (here the instructions I am following).

I am running everything under Ubuntu 18.04.

The error I get is

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-javadoc-plugin:3.0.1:jar (attach-javadocs) on project common: MavenReportException: Error while generating Javadoc: Unable to find javadoc command: The javadoc executable '/usr/lib/jvm/default-java/bin/javadoc' doesn't exist or is not a file. Verify the JAVA_HOME environment variable. -> [Help 1] [ERROR]

Still, if I do sudo ./mvnw -version, I get

Apache Maven 3.6.0 (97c98ec64a1fdfee7767ce5ffb20918da4f719f3; 2018-10-24T18:41:47Z) Maven home: /root/.m2/wrapper/dists/apache-maven-3.6.0-bin/7q9b549jss6tgtr7gdokcthm4f/apache-maven-3.6.0 Java version: 11.0.4, vendor: Ubuntu, runtime: /usr/lib/jvm/java-11-openjdk-amd64 Default locale: en_AU, platform encoding: UTF-8 OS name: "linux", version: "4.15.0-58-generic", arch: "amd64", family: "unix"

I also get which java

/usr/bin/java

and

echo $JAVA_HOME

/usr/lib/jvm/java-1.11.0-openjdk-amd64

2
javamaven

2 Answers

1
votes

I think the problem is that you have a Java 11 JRE package installed rather than a JDK.

On my Ubuntu 18.04 system, there is a /usr/bin/javadoc installed. Running apt-file find javadoc | bin/javadoc tells me that it came from the openjdk-11-jdk-headless package. (Not the openjdk-11-jre-headless package.)

0
votes

it s not a question of JDK or JRE. Since Java9, this command disappear from bin folder