Meghanada-Mode 
A Better Java Development Environment for Emacs
Meghanada is a new minor-mode (meghanada-mode) that aims at improving the editing
experience for the Java. It works by using a combination of an Emacs
package and meghanada-server.
Features:
- Easy install
- Auto update server module
- Gradle and Maven project support
- No need build tool's plugin
- Run build tool task
- Compile your project
- Syntax check and analyze java source (
flycheck-meghanada) - Support
Generic Types - Code completion with company-mode (
company-meghanada) - Optimize import
- Jump declaration
- Run Junit test (include test runner)
- Diagnostic reporting with flycheck (
flycheck-meghanada) - Show symbol's type info with
el-doc - Search references
Meghanada tested only linux (maybe macOS OK). windows not support.
(Welcome contributions !)
Dependencies
Meghanada has been developed Emacs 25.1.1
Elisp dependencies
| Package | Version |
|---|---|
cl-lib |
0.5 |
| yasnippet | 0.6.1 |
| company-mode | 0.9.0 |
| flycheck | 0.23 |
Meghanada-Server
meghanada-mode require meghanada-server and JDK (not JRE).
meghanada-server provides an interface to meghanada-mode. It uses a simple protocol
based on S-expressions. This server, written in java, requires the following
packages to be installed on your system:
- JDK 1.8
The Meghanada architecture is almost the same as ensime. It is client server model.
Meghanada updates any information when saving and compile the java file.
If the completion candidate and others are incorrect, please fix the compile error.
Installation
Elisp
Install meghanada from melpa.
Configuration
(require 'meghanada)
(add-hook 'java-mode-hook
(lambda ()
;; meghanada-mode on
(meghanada-mode t)
(setq c-basic-offset 2)
;; use code format
(add-hook 'before-save-hook 'meghanada-code-beautify-before-save)))Meghanada-Server
The server will be automatically installed to ~/.emacs/meghanada/meghanada-x.x.jar.
If you open a java file and set meghanada-mode, a meghanada-server process starts automatically and connects to your emacs.
Updating
The server will be automatically updated.To manually update bellows, type
M-x meghanada-update-server
Auto completion
Auto completion is supported by comapany-mode.
Syntax/error checking
Error checking is supported by flycheck.
Customize
To customize other aspects of its behavior, type M-x customize-group RET meghanada .
Usage
Here is a list of available interactive commands.
meghanada-install-server
Download and install meghanada-server jar.
meghanada-update-server
Download and update meghanada-server jar. and restart server process.
meghanada-server-start
Start meghanada-server process and connect to server.
meghanada-mode call this function by default. when open java file and set meghanada-mode.
meghanada-restart
Restart meghanada-server process and client process.
meghanada-server-kill
Kill meghanada-server process.
meghanada-client-direct-connect
Connect to other meghanada-server directly.
meghanada-client-connect
Connect to meghanada-server . Call automatically at the start meghanada-mode.
meghanada-client-disconnect
Disconnect from meghanada-server .
meghanada-client-ping
Send ping meghanada-server
meghanada-clear-cache
Clear meghanada-server's project cache data.
meghanada-import-all (C-c C-r i)
Add import all unqualified classes.
meghanada-optimize-import (C-c C-r o)
Import all and remove unused import statement.
The format of the import statement will be in google-java-format.
meghanada-local-variable (C-c C-r r)
Introduce local variable. (need expression is end ;)
meghanada-compile-file (C-c C-c C-c)
Compile file (and related files).
meghanada-project-compile (C-c C-c c)
Compile project (full build and reindex).
meghanada-switch-testcase (C-M-,)
Switch testcase or source.
meghanada-exec-main
Run main class.
meghanada-debug-main
Debug main class.
meghanada-reference
Find usage (method call, field access, class).
meghanada-typeinfo
Show type hierarchies and implements interfaces.
meghanada-run-junit-class (C-c C-c C-t)
Run Junit test class.
meghanada-run-junit-test-case (C-c C-c t)
Run Junit testcase (select from imenu).
meghanada-debug-junit-class (C-c C-c C-t)
Debug Junit test class.
meghanada-debug-junit-test-case (C-c C-c t)
Debug Junit testcase (select from imenu).
meghanada-run-task (C-v t)
Run build tool task.
meghanada-jump-declaration (M-.)
Goto declaration.
meghanada-back-jump (M-,)
Go back from declaration position.
meghanada-code-beautify
Format buffer code. The default formatter is google-java-format
Customize code formatter
meghanada-mode uses google-java-format by default for formatter.
It also supports eclipse formatter.
If you want to customize the formatter, you uses the exported eclipse format settings.
To import the settings, change the name of the exported file to meghanadaFormatter.xml and put it in the project root.
Debug
meghanada-mode has no debugger yet. However, external debugger is supported.
if you want to debug your code, execute meghanada-debug-xxxx function and then use realgud etc.
# in Emacs now:
M-x meghanada-debug-junit-class
Please wait ...
M-x realgud:jdb
Run jdb (like this): jdb -attach 6006
Set uncaught java.lang.Throwable
Set deferred uncaught java.lang.Throwable
Initializing jdb ...
>
VM Started: No frames on the current call stack
main[1] stop at example.MyClass:100 // set breakpoint
main[1] run
Troubleshooting
See *meghanada-server-log* buffer. or /tmp/meghanada_server.log.
Please press C-g when emacs seems to hang.
Setting example
(use-package autodisass-java-bytecode
:ensure t
:defer t)
(use-package google-c-style
:defer t
:ensure t
:commands
(google-set-c-style))
(use-package meghanada
:defer t
:init
(add-hook 'java-mode-hook
(lambda ()
(google-set-c-style)
(google-make-newline-indent)
(meghanada-mode t)
(smartparens-mode t)
(rainbow-delimiters-mode t)
(highlight-symbol-mode t)
(add-hook 'before-save-hook 'meghanada-code-beautify-before-save)))
:config
(use-package realgud
:ensure t)
(setq indent-tabs-mode nil)
(setq tab-width 2)
(setq c-basic-offset 2)
(setq meghanada-server-remote-debug t)
(setq meghanada-javac-xlint "-Xlint:all,-processing")
:bind
(:map meghanada-mode-map
("C-S-t" . meghanada-switch-testcase)
("M-RET" . meghanada-local-variable)
("C-M-." . helm-imenu)
("M-r" . meghanada-reference)
("M-t" . meghanada-typeinfo)
("C-z" . hydra-meghanada/body))
:commands
(meghanada-mode))
(defhydra hydra-meghanada (:hint nil :exit t)
"
^Edit^ ^Tast or Task^
^^^^^^-------------------------------------------------------
_f_: meghanada-compile-file _m_: meghanada-restart
_c_: meghanada-compile-project _t_: meghanada-run-task
_o_: meghanada-optimize-import _j_: meghanada-run-junit-test-case
_s_: meghanada-switch-test-case _J_: meghanada-run-junit-class
_v_: meghanada-local-variable _R_: meghanada-run-junit-recent
_i_: meghanada-import-all _r_: meghanada-reference
_g_: magit-status _T_: meghanada-typeinfo
_l_: helm-ls-git-ls
_q_: exit
"
("f" meghanada-compile-file)
("m" meghanada-restart)
("c" meghanada-compile-project)
("o" meghanada-optimize-import)
("s" meghanada-switch-test-case)
("v" meghanada-local-variable)
("i" meghanada-import-all)
("g" magit-status)
("l" helm-ls-git-ls)
("t" meghanada-run-task)
("T" meghanada-typeinfo)
("j" meghanada-run-junit-test-case)
("J" meghanada-run-junit-class)
("R" meghanada-run-junit-recent)
("r" meghanada-reference)
("q" exit)
("z" nil "leave"))TODO
- Refactoring
Contributing
Contributions are extremely welcome! Please push PR to dev branch.
License
GPL v3, See LICENSE file.