Configuring Java

Supported Versions

• v2017:

The default version is Java 1.7. This is the version that is especially used when you start java.

• v2020:

The default version is Java 14. This is the version that is especially used when you start java.

Binary to use

To use a Java version that is different from the default one:

• v2017: use /usr/lib/jvm/java-[VERSION]-openjdk-amd64/jre/bin/java (replacing [VERSION] with the desired Java version),
• v2020:
  • go on Environment > Java,
  • or use JAVA_VERSION=[VERSION] java (replacing [VERSION] with the desired Java version).

Environment

Your Java environment starts off empty, with no ready installed libraries.

HTTP deployment

To deploy an HTTP application with Java, create a User program type site in the Web > Sites section.

You need to specify the command that will start your Java application, for example:

• v2017:

$ /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java -Djava.net.preferIPv4Stack=true -Xmx512m -jar jenkins.war --httpListenAddress=0.0.0.0 --httpPort=$PORT

• v2020:

$ java -Xmx512m -jar jenkins.war --httpListenAddress=0.0.0.0 --httpPort=$PORT