nvim-jdtls

Extensions for the built-in Language Server Protocol support in Neovim (>= 0.5) for eclipse.jdt.ls.

Warning: This is early state. Neovim 0.5 hasn't been released yet, so APIs can change and things may break.

Extensions

• Command to organize imports
• Open class file contents
• Code action extensions (java.apply.workspaceEdit).
• toString generation.
• hashCode and equals generation.

Installation

• Requires Neovim HEAD/nightly
• nvim-jdtls is a plugin. Install it like any other Vim plugin.
• Call :packadd nvim-jdtls if you install nvim-jdtls to 'packpath'.

Usage

nvim-jdtls doesn't contain logic to spawn a LSP client for eclipse.jdt.ls, see :help lsp for information on how to launch a LSP client. To make use of all the functionality nvim-jdtls provides, you need to override some of the lsp callbacks, set some extra capabilities and set a couple of initialization options.

The callbacks:

  local jdtls = require 'jdtls'
  local orig_publishDiagnostics = vim.lsp.callbacks["textDocument/publishDiagnostics"] 
  local function publish_diagnostics(err, method, result) then
    local uri = result.uri
    local bufnr = vim.uri_to_bufnr(uri)
    jdtls.save_diagnostics(bufnr, result.diagnostics) -- jdtls needs diagnostic information for code actions
    orig_publishDiagnostics(err, method, result)
  end
  vim.lsp.callbacks["textDocument/publishDiagnostics"] = publish_diagnostics,
  vim.lsp.callbacks['textDocument/declaration'] = jdtls.location_callback(true),
  vim.lsp.callbacks['textDocument/definition'] = jdtls.location_callback(true),
  vim.lsp.callbacks['textDocument/typeDefinition'] = jdtls.location_callback(true),
  vim.lsp.callbacks['textDocument/implementation'] = jdtls.location_callback(true),
  vim.lsp.callbacks['textDocument/references'] = jdtls.location_callback(false),
  vim.lsp.callbacks['workspace/applyEdit'] = jdtls.workspace_apply_edit,

Additional capabilities:

local capabilities = vim.lsp.protocol.make_client_capabilities()
capabilities.textDocument.codeAction = {
  dynamicRegistration = false;
  codeActionLiteralSupport = {
    codeActionKind = {
      valueSet = {
        "source.generate.toString",
        "source.generate.hashCodeEquals"
      };
    };
  };
}
capabilities.workspace = {
  symbol = {
    dynamicRegistration = false;
    symbolKind = {
      valueSet = (function()
        local res = {}
        for k in pairs(vim.lsp.protocol.SymbolKind) do
        if type(k) == 'number' then table.insert(res, k) end
        end
        return res
      end)();
    };
  };
  applyEdit = true;
}

Initialization options:

config['init_options'] = {
  extendedClientCapabilities = {
    classFileContentsSupport = true;
    generateToStringPromptSupport = true;
    hashCodeEqualsPromptSupport = true;
  };
}

You may also want to create mappings for the code action command and to organize imports:

nnoremap <A-CR> <Cmd>lua require'jdtls'.code_action()<CR>
nnoremap <A-o> <Cmd>lua require'jdtls'.organize_imports()<CR>