Java is installed as part of the Operating System but we would strongly recommend against using that version - we cannot guarantee scientific reproducibility with that version. Please use the java modules.

Each Java module sets

    _JAVA_TOOL_OPTIONS -Xmx1g

This sets the heap memory to 1GB. If you need more, set the environment variable _JAVA_OPTIONS which overrides _JAVA_TOOL_OPTIONS

    export _JAVA_OPTIONS="-Xmx5g"