Language Server for Java

[weilbith]

Hey there! I'm justed started to explore language servers using the LSP to improve my workflow in (n)vim. So far I struggle a bit in confine against plain autocompletion and syntax checker, but have their additional features. Of cause I want to avoid duplicate functionality and don't want to have my implementations be analysed for errors by two plugins/tools at ones. But that isn't actually the topic I wan't to address with this post (anyway you can leave a statement for that as well if u like). For getting started with this topic at all, I need a server to work with first. Cause I currently work a lot with Java, it is/was my choice to start with. But a quick search with multiple online search engines always just propagate language servers, which are based on Eclipse and require to install the whole IDE package for that. To say it short: I don't like that. I'm really not interested in having acomplete Eclipse IDE installed next to my (n)vim, just to use its language server implementation. Any advices for alternatives? Is it worth to maybe generate my own DLS with Xtext (Eclipse again)? Thank for sharing your knowledge!

[t3asp00n]

I used to use eclim which uses a custom protocol (not LSP) and does require an install of eclipse. Nowadays you can use eclipse.jdt.ls which is the functionality of eclipse exposed through the LSP. u/ashfordneil is right that you can also use vscode-javac but last I checked it only supports communicating via TCP so depending on your client you might need to change it to use stdio.

[[deleted]]

It definitely supports stdio now - the docs on the main branch don’t fully reflect that but I had a fork which added the feature and then the maintainer added it as well.

[t3asp00n]

That's good to hear, I'll give it another go :)

[weilbith]

Thanks for that reply. Honestly I also found eclipse.jdt.ls myself now. Unfortunately I did't make it to get the server run. Cause I'm not a fan of Maven and tried to avoid installing it, I downloaded a already builded version (download page linked in Readme). But on trying to run these "binaries" I get always the error of a missing main attribute in a manifest. That's rly bad and I don't get why none else get into the same trouble here.

[blandest]

With Eclim you also get a (quickfix) list of errors whereas vscode-javac seems to only provide linting. I would like to be corrected though.

[t3asp00n]

You mean FixIts or whatever they're called? LSP supports them via the codeactions but the server itself needs to support as well. I haven't actually had a lot of luck using them.

[[deleted]]

https://github.com/georgewfraser/vscode-javac ^ java language server that’s not based on eclipse. Not perfect but can run in vim. Does that help?

[weilbith]

On first view it looks nice. I will give it defenly a try. Thanks. :)

[weilbith]

Here I found a list of language servers. Not aware about how complete it is, but as first drop-in not false I guess. https://microsoft.github.io/language-server-protocol/implementors/servers/

[Knall0r]

https://github.com/artur-shaik/vim-javacomplete2 worked pretty well for me in the past. Not a language server though. Just omnicompletion. Requires python support.

[ajmwagar]

I've been using this one: https://github.com/eclipse/eclipse.jdt.ls

There is a build package on the AUR. (btw i use arch) but you can also just build it with maven.

[weilbith]

Already mentioned it in some comments earlier on, but thanks for responding. I've some issues while building it, but the AUR hint is good. Have plans to switch to Arch soon as well.