Unable to locate a Java Runtime that supports -Declipse.application=org.eclipse.jdt.ls.core.id1.

[Syntonica]

My install of JDTLS used to work, more or less, but one day, it randomly stopped working with this error.

I've tried several JDKs from 17 to 22, using OpenJDKs from Azul, Adoptium and Oracle's own JDK22.

Pray, tell me, which flavor of JRE would JDTLS like? :) Is this a skill issue, a bug, or a feature?

If it matters, I'm using Mac Intel, OS11 Big Sur (my MacBook Protato.)

[rgrunber]

Any JRE >= 17 (need not be a JDK but that's also fine) should work. Is the JRE that you are using on the system PATH ? How are you launching JDT-LS ?

[Syntonica]

I've used several JDKs and a JRE, as I originally stated, all on my path. To start the server, I've tried both the executable and the Python script and just using one big long statement in the terminal.

Previously, the executable worked fine, although I had to revert to an earlier version of JDTLS (which I no longer recall which release it was.) It ran with JDK17. However, at some point, it stopped working. The only change I'd made to my system was to update my JDKs (8/11/17).

If anybody is running this on a Mac without benefit of VSCode and similar, please let m know which versions of the JRE/JDK and JDTLS you are using. TIA.

[rgrunber]

You mentioned every JDK/JRE is on the PATH but which one is used when you call java --version ? Do you have anything set for JAVA_HOME environment variable ?

[Syntonica]

Whichever one I set. I have no issues with other jar files running, the JREs are there and responding.

[robstryker]

I think a trace of the console would be more clear? How EXACTLY are you launching the language server? Are you starting with the command with (for example) /some/path/to/jdk-99-99/bin/java ? Do you have JAVA_HOME set?

From what I can tell, the "Unable to locate a Java Runtime that supports " etc part is from Mac itself and is what happens when the operating system is trying to find a java to use, rather than output from an actual java command.

[Syntonica]

Well, if that's not the most annoying thing ever. In 15 years of Java on the Mac, I've never had to explicitly set JAVA_HOME for any reason. MacOS has always just magically pointed to the newest JRE it could find in the Java folder and I'd come to believe that it was setting the Java variables automatically behind the scenes. Anyway, I explicitly set the path and JDTLS runs fine.

Skill issue.

Thanks.

[robstryker]

Great!