Just install and start writing public static void main(String[] args).
Demo.mp4
- ✅ Diagnostics & Auto Completion
- ✅ Automatic DAP debug configuration
- ✅ Running tests
- Everything necessary will be installed automatically
- Uses nvim-lspconfig to setup
jdtls - Realtime server settings updates is possible using neoconf
- Auto loads necessary
jdtlsplugins- Supported plugins are,
lombokjava-testjava-debug-adapter
- Supported plugins are,
🔸details
- Install the plugin
Using lazy.nvim
return {
'nvim-java/nvim-java',
dependencies = {
'nvim-java/lua-async-await',
'nvim-java/nvim-java-core',
'nvim-java/nvim-java-test',
'nvim-java/nvim-java-dap',
'MunifTanjim/nui.nvim',
'neovim/nvim-lspconfig',
'mfussenegger/nvim-dap',
{
'williamboman/mason.nvim',
opts = {
registries = {
'github:nvim-java/mason-registry',
'github:mason-org/mason-registry',
},
},
}
},
}- Setup nvim-java before
lspconfig
require('java').setup()- Setup jdtls like you would usually do
require('lspconfig').jdtls.setup({})Yep! That's all :)
🔸details
JavaRunnerRunMain- Runs the application or selected main class (if there are multiple main classes)
:JavaRunnerRunMain
:JavaRunnerRunMain <arguments> <to> <pass>JavaRunnerStopMain- Stops the running applicationJavaRunnerToggleLogs- Toggle between show & hide runner log window
JavaDapConfig- DAP is autoconfigured on start up, but in case you want to force configure it again, you can use this API
JavaTestRunCurrentClass- Run the test class in the active bufferJavaTestDebugCurrentClass- Debug the test class in the active bufferJavaTestRunCurrentMethod- Run the test method on the cursorJavaTestDebugCurrentMethod- Debug the test method on the cursorJavaTestViewLastReport- Open the last test report in a popup window
🔸details
built_in.run_app- Runs the application or selected main class (if there are multiple main classes)
require('java').runner.built_in.run_app({})
require('java').runner.built_in.run_app({'arguments', 'to', 'pass', 'to', 'main'})built_in.stop_app- Stops the running application
require('java').runner.built_in.stop_app()built_in.toggle_logs- Toggle between show & hide runner log window
require('java').runner.built_in.toggle_logs()config_dap- DAP is autoconfigured on start up, but in case you want to force configure it again, you can use this API
require('java').dap.config_dap()run_current_class- Run the test class in the active buffer
require('java').test.run_current_class()debug_current_class- Debug the test class in the active buffer
require('java').test.debug_current_class()run_current_method- Run the test method on the cursor
require('java').test.run_current_method()debug_current_method- Debug the test method on the cursor
require('java').test.debug_current_method()view_report- Open the last test report in a popup window
require('java').test.view_last_report()🔸details
Neoconf can be used to manage LSP
setting including jdtls. Neoconf allows global configuration as well as project
vice configurations. Here is how you can set Jdtls setting on neoconf.json
{
"lspconfig": {
"jdtls": {
"java.configuration.runtimes": [
{
"name": "JavaSE-21",
"path": "/opt/jdk-21",
"default": true
}
]
}
}
}Pass the settings to Jdtls setup.
require('lspconfig').jdtls.setup({
settings = {
java = {
configuration = {
runtimes = {
{
name = "JavaSE-21",
path = "/opt/jdk-21",
default = true,
}
}
}
}
}
})🔸details
For most users changing the default configuration is not necessary. But if you want, following options are available
{
-- list of file that exists in root of the project
root_markers = {
'settings.gradle',
'settings.gradle.kts',
'pom.xml',
'build.gradle',
'mvnw',
'gradlew',
'build.gradle',
'build.gradle.kts',
'.git',
},
-- load java test plugins
java_test = {
enable = true,
},
-- load java debugger plugins
java_debug_adapter = {
enable = true,
},
jdk = {
-- install jdk using mason.nvim
auto_install = true,
},
notifications = {
-- enable 'Configuring DAP' & 'DAP configured' messages on start up
dap = true,
},
}🔸details
Following is the high level idea. Jdtls is the language server nvim-java communicates with. However, we don't have all the features we need just in Jdtls. So, we are loading java-test & java-debug-adapter extensions when we launch Jdtls. Once the language server is started, we communicate with the language server to do stuff.
For instance, to run the current test,
- Request Jdtls for test classes
- Request Jdtls for class paths, module paths, java executable
- Request Jdtls to start a debug session and send the port of the session back
- Prepare TCP connections to listen to the test results
- Start nvim-dap and let user interactions to be handled by nvim-dap
- Parse the test results as they come in
- Once the execution is done, open a window show the test results
┌────────────┐ ┌────────────┐
│ │ │ │
│ Neovim │ │ VSCode │
│ │ │ │
└─────▲──────┘ └──────▲─────┘
│ │
│ │
│ │
│ │
┌───────▼───────┐ ┌──────────────▼──────────────┐
│ │ │ │
│ nvim-java │ │ Extension Pack for Java │
│ │ │ │
└───────▲───────┘ └──────────────▲──────────────┘
│ │
│ │
│ │
│ │
│ │
│ ┌───────────┐ │
│ │ │ │
└──────────────► JDTLS ◄────────────┘
│ │
└───▲───▲───┘
│ │
│ │
│ │
│ │
│ │
┌───────────────┐ │ │ ┌────────────────────────┐
│ │ │ │ │ │
│ java-test ◄────────┘ └─────────► java-debug-adapter │
│ │ │ │
└───────────────┘ └────────────────────────┘
nvim-jdtls is a plugin that follows "Keep it simple, stupid!" approach. If you love customizing things by yourself, then give nvim-jdtls a try. I may or may not have copied some code 😉 Beauty of Open source!