Cannot specify a different Java home when starting Run from Windows cmd

[ThorbenLindhauer]

Environment (Required on creation)

• Windows 10
• cmd (didn't test powershell)

Description (Required on creation; please attach any relevant screenshots, stacktraces, log files, etc. to the ticket)

If the Java executable on the path points to a version < 17, I have to use the JAVA_HOME environment variable to specify a Java 17 installation. This doesn't work in the environment above (may, but probably is not related to the path containing a space character).

Steps to reproduce (Required on creation)

1. Download and unpack Run (I used version 7.20.1)
2. Open cmd in Run home directory
3. set JAVA_HOME=C:\Program Files\Java\jdk-17.0.2 (using quotes around the value leads to a different problem in the start script)
4. start.bat

Observed Behavior (Required on creation)

• Run doesn't start
• Output is:

  Setting JAVA property to "C:\Program Files\Java\jdk-17.0.2\bin\java"
  Java version is 1.8.0_242
  You must use at least JDK 17 to start Camunda Platform Run.

Expected behavior (Required on creation)

• Run starts successfully, using the JDK I have specified via JAVA_HOME

Root Cause (Required on prioritization)

• It seems the reference to JAVA on this line uses the Java executable on the path, not the JAVA variable that the script defines

Solution Ideas

Hints

Links

Breakdown

### Pull Requests
- [ ] https://github.com/camunda/camunda-bpm-platform/pull/3958
- [ ] https://github.com/camunda/camunda-bpm-platform-maintenance/pull/1123

Dev2QA handover

• [ ] Does this ticket need a QA test and the testing goals are not clear from the description? Add a Dev2QA handover comment

[yanavasileva]

I will have a look at the issue this week.

[yanavasileva]

I was able to reproduce the issue. I think we need to address the issue as it could be a common use case. I created a PR but the use case a path with space is not working. So a bit more work is needed.

An alternative will be to remove the java check.

Workaround: use JAVA_HOME with PATH assignment:

set JAVA_HOME=C:\Program Files\Java\jdk-17.0.2\bin\java
set PATH=%JAVA_HOME%\bin;%PATH%

[yanavasileva]

Notes:

• when path with empty space is used and wrap around the value of parameter with quotes (set JAVA_HOME="C:\Tools\jdk\ab ds\jdk-17.0.7" ), the IF "x%JAVA_HOME%" == "x" check fails in run.bat script
• it seems that it's better practice to not include the quotes in the variable's value but if necessary wrap around the whole name and value expression: set "name=value"
• To fix the Java check and consider empty space in the Java path, I suggest to
  • overwrite the PATH parameter and include the JAVA_HOME in it. Implications: in the command window where the run script is executed, the PATH variable will be with a new value.
  • wrap around the name=value pair for JAVA and PATH variables
  • pros: with small addition the issue is resolved and the Java from the JAVA_HOME will be considered anytime
• Alternative:
  • use java -fullversion and try to reduce complexity of the Java check (haven't figured out how yet)
  • remove the Java check (cons: no good indication what when wrong when lower Java version is used)

[yanavasileva]

To reviewer:

• I will do the backport after master review
• Please let me know if I should reassign to another review if you can't test on Windows OS.

[yanavasileva]

Notes:

• merged to master so the change will be part of the next alpha
• assigning the backport to different dev that works on Windows OS to get his review on the change