How are folks using this with Java?

[dsabsay]

I was able to get the Java jdtls working with the following config:

if executable('java') && filereadable(expand('~/lsp/jdt-language-server-1.14.0-202207211651/plugins/org.eclipse.equinox.launcher_1.6.400.v20210924-0641.jar'))
    au User lsp_setup call lsp#register_server({
                \ 'name': 'eclipse.jdt.ls',
                \ 'cmd': {server_info->[
                \ 'java',
                \ '-Declipse.application=org.eclipse.jdt.ls.core.id1',
                \ '-Dosgi.bundles.defaultStartLevel=4',
                \ '-Declipse.product=org.eclipse.jdt.ls.core.product',
                \ '-Dlog.level=ALL',
                \ '-noverify',
                \ '-Dfile.encoding=UTF-8',
                \ '-Xmx1G',
                \ '--add-modules=ALL-SYSTEM',
                \ '-jar',
                \ expand('~/lsp/jdt-language-server-1.14.0-202207211651/plugins/org.eclipse.equinox.launcher_1.6.400.v20210924-0641.jar'),
                \ '-configuration',
                \ expand('~/lsp/jdt-language-server-1.14.0-202207211651/config_mac'),
                \ '-data',
                \ getcwd()
                \ ]},
                \ 'whitelist': ['java'],
                \ })
endif

While it worked for very simple things like :LspReferences or :LspDefinition for something in the same file, I found it to be quite limited.

I can't do simple navigation between classes in different packages. For example I have com.foo.bar.App that has a method returning a MyClass from com.foo.bar.qux.MyClass. :LspDefinition says it can't find any definitions. Same for :LspTypeDefinition. However, if I open com.foo.bar.qux.MyClass, those commands start working as expected from the App class.

Is there some setting I'm missing? Do I need to somehow tell the language server to load all the files in my project first?

[prabirshrestha]

You probably want to enable logs? Are you hitting into this issue #1284?

[dsabsay]

I'm looking at the logs. It doesn't look like the linked issue is related to this one.
The response coming back from the server doesn't have that jdt URI.

Here's a few of the logs (with file paths redacted):

Tue Aug  9 17:16:10 2022:["--->",1,"eclipse.jdt.ls",{"method":"textDocument/definition","on_notification":"---funcref---","params":{"textDocument":{"uri":"file:///redacted/long/path/Application.java"},"position":{"character":13,"line":98}}}]
Tue Aug  9 17:16:10 2022:["<---",1,"eclipse.jdt.ls",{"response":{"method":"window/logMessage","jsonrpc":"2.0","params":{"message":"Aug 9, 2022, 5:16:10 PM >> document/definition","type":3}}}]
Tue Aug  9 17:16:10 2022:["<---",1,"eclipse.jdt.ls",{"response":{"id":71,"jsonrpc":"2.0","result":[]},"request":{"id":71,"jsonrpc":"2.0","method":"textDocument/definition","params":{"textDocument":{"uri":"file:///redacted/long/path/Application.java"},"position":{"character":13,"line":98}}}}]

Again, after I open the file that contains the definition, the server responds properly with the file:// URI and Vim loads it.

[ipkiss42]

Assuming that com.foo.qux.MyClass is not only in a different java package but also a different LSP root folder, then what you are describing is the typical symptom of a multi-root workspace where you haven't told the client about the root folders. Folders get discovered only after you open a class in them, but before that, the language server often has no way to know where else to look for class definitions.

Each LSP client has (or should have) some way to declare the root folders. I'm not sure how it works with vim-lsp, but hopefully others can chime in.

[dsabsay]

I wasn't as precise as I should have been. App is is in the com.foo.bar package and everything I'm trying to resolve is in a separate packages in the same folder as App. I've updated my initial post to reflect this.

Your theory seems valid. getcwd() gets passed to the server itself and I start vim a few levels higher in the filesystem tree, so every class I mentioned is in a subdirectory of getcwd(). But perhaps I need to explicitly give it the folders of all packages? I assumed it would recursively search the cwd, but that doesn't seem to be happening.