eclipse.jdt.ls VS coc-java

Thanks Eclipse : https://github.com/eclipse-jdtls/eclipse.jdt.ls

I installed eclipse jdtls which worked for Java, but I was not able to go to definitions for methods/classes outside of my project (ie, libraries and such, something like in IntelliJ where you can go to the definition or implementation for the library code), so I thought it may be a limitation of nvim-lspconfig

return { { "neovim/nvim-lspconfig", dependencies = { "mfussenegger/nvim-jdtls", init = function() require("lazyvim.util").on_attach(function(_, buffer) -- stylua: ignore vim.keymap.set( "n", "di", "lua require'jdtls'.organize_imports()", { buffer = buffer, desc = "Organize Imports" } ) vim.keymap.set( "n", "dt", "lua require'jdtls'.test_class()", { buffer = buffer, desc = "Test Class" } ) vim.keymap.set( "n", "dn", "lua require'jdtls'.test_nearest_method()", { buffer = buffer, desc = "Test Nearest Method" } ) vim.keymap.set( "v", "de", "lua require('jdtls').extract_variable(true)", { buffer = buffer, desc = "Extract Variable" } ) vim.keymap.set( "n", "de", "lua require('jdtls').extract_variable()", { buffer = buffer, desc = "Extract Variable" } ) vim.keymap.set( "v", "dm", "lua require('jdtls').extract_method(true)", { buffer = buffer, desc = "Extract Method" } ) vim.keymap.set( "n", "cf", "lua vim.lsp.buf.formatting()", { buffer = buffer, desc = "Format" } ) end) end, }, ---@class PluginLspOpts opts = { ---@type lspconfig.options servers = {}, -- you can do any additional lsp server setup here -- return true if you don't want this server to be setup with lspconfig ---@type table setup = { -- example to setup with typescript.nvim jdtls = function(_, opts) local project_name = vim.fn.fnamemodify(vim.fn.getcwd(), ":p:h:t") -- vim.lsp.set_log_level('DEBUG') local workspace_dir = "/home/jake/.workspace/" .. project_name -- See `:help vim.lsp.start_client` for an overview of the supported `config` options. local config = { -- The command that starts the language server -- See: https://github.com/eclipse/eclipse.jdt.ls#running-from-the-command-line cmd = { "java", -- or '/path/to/java17_or_newer/bin/java' "-javaagent:/home/jake/.local/share/java/lombok.jar", -- '-Xbootclasspath/a:/home/jake/.local/share/java/lombok.jar', "-Declipse.application=org.eclipse.jdt.ls.core.id1", "-Dosgi.bundles.defaultStartLevel=4", "-Declipse.product=org.eclipse.jdt.ls.core.product", "-Dlog.protocol=true", "-Dlog.level=ALL", -- '-noverify', "-Xms1g", "--add-modules=ALL-SYSTEM", "--add-opens", "java.base/java.util=ALL-UNNAMED", "--add-opens", "java.base/java.lang=ALL-UNNAMED", "-jar", vim.fn.glob("/usr/share/java/jdtls/plugins/org.eclipse.equinox.launcher_*.jar"), "-configuration", "/usr/share/java/jdtls/config_linux", "-data", workspace_dir, }, root_dir = require("jdtls.setup").find_root({ ".git", "mvnw", "gradlew" settings = { java = {}, }, } require("jdtls").start_or_attach(config) return true end, -- Specify * to use this function as a fallback for any server -- ["*"] = function(server, opts) end, }, }, }, }

You can absolutely just use Gradle on the command line, and use a language server to get code intelligence in pretty much any editor you like. IntelliJ is very nice, especially for refactoring, but it doesn't have a giant advantage over any other editor, as long as you're sticking to mostly Java.

Try neovim. Builtin support for language servers which provide the basis for IDE functionality, autocomplete, auto import, code actions, refactoring, etc. I believe VSCode uses jdtls on the backend and you can use the same thing with neovim.

Is seems like valid manual to start language server here https://github.com/eclipse/eclipse.jdt.ls. Not sure what you mean by "starting it with other editors" though. It should be covered by editor own integration with the given LS.

But all of the above to say that Emacs can have the ability to some of if not more than VSCode. As others have said, the Jetbrains IDEs are a different story. They're built to actually understand the code you're writing. It's quite possible, with features like auto-insert and skeletons, to replicate some of the functionality that, say, IntelliJ does. For example, say you find-file into a new file for some Java project. When you first enter the buffer, you could setup a prompt to create a class, enum, interface etc. and then upon a selection, you have the basic relevant code for whatever the selection was made auto-inserted. Or you could just quit the prompt with C-g. Granted that takes some time to set up as well as recreating other smaller features that IntelliJ has. JDTLS can do some of this, but at the end of the day it's not a replacement for IntelliJ and I don't think JDTLS intends to be such.

Just the other day I tested VS Code Java again and apparently the Red Hat team that did the Java language support has gotten some level of null analysis turned on now. Thus I assume the Eclipse LSP https://github.com/eclipse/eclipse.jdt.ls has that support now.

Java

Check out the coc.java README, it uses jdt.ls under the hood and it supports gradle projects and maven projects (both of them wre Java build tools and dependency managers for big projects).

Just follow the directions on the eclipse-jdt.ls and coc-java on the installation process, I have no clue about that as I don't develop in java

A fork of the VSCode extension, coc-java is used by coc.nvim to provide Java support for Vim/NeoVim.

Looking through the internet I've found through https://github.com/neoclide/coc-java/issues/27#issuecomment-506283639 that `java.jdt.ls.vmargs` needs to be set. But that option is for `coc` and I want to use inbuilt `lsp` client.

If you're not using Neovim, then coc https://github.com/neoclide/coc.nvim is probably the best LSP implementation. https://github.com/neoclide/coc-java installs the eclipse language server for autocomplete, linting etc.