[MNG-6003] Drastically reduce JAVA_HOME discovery code

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.3.9
• Fix Version/s: 3.5.0-alpha-1, 3.5.0
• Component/s: Command Line
• Assignee: Michael Osipov
• Reporter: Michael Osipov
• Created: 15/Apr/16 18:52
• Updated: 06/Dec/21 22:11
• Resolved: 30/Jan/17 21:33

Description

Our installation documentation several times requires that JAVA_HOME is set and points to a valid JDK. Though, tens of lines in mvn and mvn.cmd perform some magic to discover it when it is not set. This completely contradicts our requirement that JAVA_HOME must be set.

We can drastically reduce this code by checking if JAVA_HOME is set and use it, if not perform which java and use that to run Maven. Not adhering to our requirements is deemed to undefined behavior. A developer must be able to set this simple env var properly. In most cases on Unix/Linux OpenJDK is installed anyway which means that which java points to a JDK anyway. For instance, the JAVA_HOME discovery on FreeBSD competely fails and sets it to /usr/local because /usr/local/bin/java is actually a wrapper script.

Issue Links

• is depended upon by: MNG-5579 Unify error output/check logic from shell and batch scripts
• is duplicated by: MNG-5025 CLONE - JAVA_HOME auto discovery - also for windows with mvn.cmd
• is related to: MNG-6456 Log $JAVA_HOME when there is an issue with it
• is related to: MWRAPPER-27 rework mvnw* scripts to better match mvn* from Maven 3.8
• mentioned in: Page Loading...