Crashes on Arch Linux `NoSuchFileException: /usr/java`

[VojtechStep]

On my machine, the folder /usr/java does not exist, and apparently that crashes the server (logs below).

I can see that in the JavaHomeHelper class, some folders are tested for the presence of 'bin/javac', however, the check crashes if the searched folder doesn't even exist (line).

I'm not sure what the purpose is of that rethrow, as in my opinion an exception in that place should just signal the checker to move on to another entry. Replacing the throw new RuntimeException(e) with continue fixes the problem.

Full log:

14:19:09.050	INFO	LSP connect	Reading messages from queue...
14:19:09.050	INFO	LSP$1MessageReader run	Placing incoming messages on queue...
14:19:09.199	SEVERE	LSP connect	Not a JSON Object: null
java.lang.IllegalStateException: Not a JSON Object: null
	at com.google.gson.JsonElement.getAsJsonObject(JsonElement.java:91)
	at org.javacs.JavaLanguageServer.didChangeConfiguration(JavaLanguageServer.java:217)
	at org.javacs.lsp.LSP.connect(LSP.java:288)
	at org.javacs.Main.main(Main.java:30)

14:19:09.415	INFO	JavaLanguageServer lint	Lint 1 files...
14:19:09.468	INFO	ScanClassPath jdkTopLevelClasses	Searching for top-level classes in the JDK
14:19:09.665	INFO	ScanClassPath jdkTopLevelClasses	Found 5794 classes in the java platform
Class path:
Doc path:
14:19:09.735	SEVERE	Main main	java.nio.file.NoSuchFileException: /usr/java
java.lang.RuntimeException: java.nio.file.NoSuchFileException: /usr/java
	at org.javacs.JavaHomeHelper.check(JavaHomeHelper.java:84)
	at org.javacs.JavaHomeHelper.linuxJavaHome(JavaHomeHelper.java:62)
	at org.javacs.JavaHomeHelper.javaHome(JavaHomeHelper.java:30)
	at org.javacs.Docs.findSrcZip(Docs.java:53)
	at org.javacs.Docs.srcZip(Docs.java:39)
	at org.javacs.Docs.<init>(Docs.java:18)
	at org.javacs.JavaCompilerService.<init>(JavaCompilerService.java:37)
	at org.javacs.JavaLanguageServer.createCompiler(JavaLanguageServer.java:112)
	at org.javacs.JavaLanguageServer.compiler(JavaLanguageServer.java:39)
	at org.javacs.JavaLanguageServer.lint(JavaLanguageServer.java:61)
	at org.javacs.JavaLanguageServer.doAsyncWork(JavaLanguageServer.java:523)
	at org.javacs.lsp.LSP.connect(LSP.java:247)
	at org.javacs.Main.main(Main.java:30)
Caused by: java.nio.file.NoSuchFileException: /usr/java
	at java.base/sun.nio.fs.UnixException.translateToIOException(UnixException.java:92)
	at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:111)
	at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:116)
	at java.base/sun.nio.fs.UnixFileSystemProvider.newDirectoryStream(UnixFileSystemProvider.java:432)
	at java.base/java.nio.file.Files.newDirectoryStream(Files.java:475)
	at java.base/java.nio.file.Files.list(Files.java:3762)
	at org.javacs.JavaHomeHelper.check(JavaHomeHelper.java:81)
	... 12 more


Process NOX (stepavo2/java-mode) stderr finished

[stupid-genius]

Same issue on Ubuntu 18.04. Creating /usr/java and /opt/java allows the server to start, but that's a pretty ugly hack.

[georgewfraser]

JavaHomeHelper is the key thing that needs to be fixed. It's job is to locate JAVA_HOME on any OS. A PR would be much appreciated!

[stupid-genius]

https://github.com/georgewfraser/java-language-server/pull/148

[ribrdb]

I'm getting this problem also on debian. Wouldn't it be better to use bazel to get the JAVA_HOME in addition to just the dependencies for bazel projects?

[drybalka]

It seems this issue can be closed now, as it was solved in https://github.com/georgewfraser/java-language-server/pull/148 On Arch just be sure to use the "java-language-server-git" package, as the release version is lagging behind and still does not include the fix.