LSP Java backend for the Java layer

Fixes #10654 Added new backend for the Java.
2018-08-21 21:47:48 +03:00 · 2018-08-21 21:47:48 +03:00 · 862d873fa8
parent 25be8ecb62
commit 862d873fa8
5 changed files with 152 additions and 6 deletions
--- a/.gitignore
+++ b/.gitignore
@ -48,6 +48,8 @@ python-*-docs-html
 /recentf
 .mc-lists.el
 nov-places
+workspace
+eclipse.jdt.ls

 # Private directory
 private/
--- a/layers/+lang/java/README.org
+++ b/layers/+lang/java/README.org
@ -24,6 +24,9 @@
    - [[#configuration-1][Configuration]]
    - [[#usage-1][Usage]]
    - [[#issues][Issues]]
+  - [[#lsp-java][LSP Java]]
+    - [[#instalation][Instalation]]
+    - [[#configuration-2][Configuration]]
 - [[#key-bindings][Key bindings]]
  - [[#meghanada-1][Meghanada]]
    - [[#server][Server]]
@ -58,6 +61,7 @@
    - [[#refactoring-2][Refactoring]]
    - [[#tests-1][Tests]]
    - [[#repl][REPL]]
+  - [[#lsp-java-1][LSP Java]]
  - [[#maven][Maven]]
  - [[#gradle][Gradle]]

@ -69,6 +73,7 @@ This layer adds support for the Java language.
  - [[https://github.com/mopemope/meghanada-emacs][Meghanada]] client/server (default),
  - [[http://eclim.org][Eclim]] client/server,
  - [[https://ensime.github.io/][ENSIME]] client/server.
+  - [[https://github.com/emacs-lsp/lsp-java][LSP Java]] client/server.
 - Each provides:
  - Auto-completion using company
  - Linting using flycheck integration
@ -231,6 +236,40 @@ will suffice do the trick.
 ENSIME is originally built for Scala, so support for java is not complete, in
 particular refactoring doesn't work.

+** LSP Java
+LSP Java is the Java adapter for [[https://github.com/emacs-lsp/lsp-mode][LSP Mode]] which is the Emacs client for [[https://github.com/Microsoft/language-server-protocol][Language
+Server Protocol]].
+
+*** Instalation
+Download either [[http://download.eclipse.org/jdtls/snapshots/jdt-language-server-latest.tar.gz][latest]] or [[http://download.eclipse.org/jdtls/snapshots/?d][a specific version]] of Eclipse JDT Language Server
+distribution to =~/.emacs.d/eclipse.jdt.ls/server/=
+
+If you choose to have the server installed in a different directory, set
+=lsp-java-server-install-dir=
+
+If you choose to have the server installed in a different directory, set
+=lsp-java-server-install-dir=
+On Linux/MacOS you could install/update Eclipse JDT Language Server via running the following commands:
+
+#+BEGIN_SRC bash
+  rm -rf ~/.emacs.d/eclipse.jdt.ls/server/
+  mkdir -p ~/.emacs.d/eclipse.jdt.ls/server/
+  wget http://download.eclipse.org/jdtls/snapshots/jdt-language-server-latest.tar.gz -O /tmp/jdt-latest.tar
+  tar xf /tmp/jdt-latest.tar -C ~/.emacs.d/eclipse.jdt.ls/server/
+#+END_SRC
+
+*** Configuration
+Specify the list of projects which will be imported in the LSP server. Note that
+if project is not imported JDT server will provide only basic java support due
+to lack of classpath information.
+
+#+BEGIN_SRC emacs-lisp
+(java :variables java-backend 'lsp
+                 lsp-java--workspace-folders '(list "/path/to/project1"
+                                                    "/path/to/project2"
+                                                    ...))
+#+END_SRC
+
 * Key bindings
 ** Meghanada
 *** Server
@ -243,7 +282,7 @@ particular refactoring doesn't work.
 | ~SPC m D k~ | Kill server                                  |
 | ~SPC m D l~ | Clear server cache                           |
 | ~SPC m D p~ | Ping server                                  |
- | ~SPC m D r~ | Restarrt server                              |
+ | ~SPC m D r~ | Restart server                               |
 | ~SPC m D s~ | Start server                                 |
 | ~SPC m D u~ | Update server                                |
 | ~SPC m D v~ | Print version of the server                  |
@ -522,6 +561,34 @@ particular refactoring doesn't work.
 | ~SPC m s r~ | send region to the REPL                                             |
 | ~SPC m s R~ | send region to the REPL and focus the REPL buffer in =insert state= |

+** LSP Java
+
+| Key Binding   | Description                           |
+|---------------+---------------------------------------|
+| ~SPC m g g~   | Go to definition                      |
+| ~SPC m g r~   | Find references                       |
+| ~SPC m g R~   | Peek references using ~lsp-ui~        |
+| ~SPC m g d~   | Goto type definition                  |
+| ~SPC m g a~   | Search type in project                |
+| ~SPC m g A~   | Search type in project using ~lsp-ui~ |
+| ~SPC m h h~   | Describe thing at point               |
+| ~SPC m e l~   | List project errors/warnings          |
+| ~SPC m p u~   | Refresh user settings                 |
+| ~SPC m e a~   | Execute code action                   |
+| ~SPC m q r~   | Restart workspace                     |
+| ~SPC m r o i~ | Organize imports                      |
+| ~SPC m r r~   | Rename symbol                         |
+| ~SPC m r a i~ | Add import                            |
+| ~SPC m r a m~ | Add unimplemented methods             |
+| ~SPC m r c p~ | Create parameter                      |
+| ~SPC m r c f~ | Create field                          |
+| ~SPC m r e c~ | Extract constant                      |
+| ~SPC m r e l~ | Extract local                         |
+| ~SPC m r e m~ | Extract method                        |
+| ~SPC m c c~   | Build project                         |
+| ~SPC m a n~   | Actionable notifications              |
+| ~SPC m =~     | Format code                           |
+
 ** Maven

 | Key Binding     | Description                                          |
--- a/layers/+lang/java/config.el
+++ b/layers/+lang/java/config.el
@ -14,8 +14,8 @@
 (spacemacs|define-jump-handlers java-mode)

 (defvar java-backend 'meghanada
-  "The backend to use for IDE features. Possible values are `eclim', `ensime'
-and `meghanada'.")
+  "The backend to use for IDE features. Possible values are `eclim', `ensime',
+ `meghanada' and `lsp'.")

 (defvar java--ensime-modes '(java-mode)
  "Modes using ensime. Mainly used to define ENSIME key bindings.")
--- a/layers/+lang/java/funcs.el
+++ b/layers/+lang/java/funcs.el
@ -29,21 +29,24 @@
  (pcase java-backend
    (`meghanada (spacemacs//java-setup-meghanada))
    (`eclim (spacemacs//java-setup-eclim))
-    (`ensime (spacemacs//java-setup-ensime))))
+    (`ensime (spacemacs//java-setup-ensime))
+    (`lsp (spacemacs//java-setup-lsp))))

 (defun spacemacs//java-setup-company ()
  "Conditionally setup company based on backend."
  (pcase java-backend
    (`meghanada (spacemacs//java-setup-meghanada-company))
    (`eclim (spacemacs//java-setup-eclim-company))
-    (`ensime (spacemacs//java-setup-ensime-company))))
+    (`ensime (spacemacs//java-setup-ensime-company))
+    (`lsp (spacemacs//java-setup-lsp-company))))

 (defun spacemacs//java-setup-flycheck ()
  "Conditionally setup flycheck based on backend."
  (pcase java-backend
    (`meghanada (spacemacs//java-setup-meghanada-flycheck))
    (`eclim (spacemacs//java-setup-eclim-flycheck))
-    (`ensime (spacemacs//java-setup-ensime-flycheck))))
+    (`ensime (spacemacs//java-setup-ensime-flycheck))
+    (`lsp (spacemacs//java-setup-lsp-flycheck))))

 (defun spacemacs//java-setup-flyspell ()
  "Conditionally setup flyspell based on backend."
@ -288,3 +291,36 @@
  (when (s-matches? (rx (+ (not space)))
                    (buffer-substring (line-beginning-position) (point)))
    (delete-horizontal-space t)))
+
+
+;; LSP Java
+
+(defun spacemacs//java-setup-lsp ()
+  "Setup LSP Java."
+  (if (configuration-layer/layer-used-p 'lsp)
+      (progn
+        (require 'lsp-java)
+        (require 'company-lsp)
+        (lsp-java-enable))
+    (message "`lsp' layer is not installed, please add `lsp' layer to your dotfile.")))
+
+(defun spacemacs//java-setup-lsp-company ()
+  "Setup lsp auto-completion."
+  (if (configuration-layer/layer-used-p 'lsp)
+      (progn
+        (spacemacs|add-company-backends
+          :backends company-lsp
+          :modes java-mode
+          :append-hooks nil
+          :call-hooks t)
+        (company-mode))
+    (message "`lsp' layer is not installed, please add `lsp' layer to your dotfile.")))
+
+(defun spacemacs//java-setup-lsp-flycheck ()
+  "Setup LSP Java syntax checking."
+  (if (configuration-layer/layer-used-p 'lsp)
+      (when (spacemacs/enable-flycheck 'java-mode)
+        (require 'lsp-ui-flycheck)
+        (lsp-ui-flycheck-enable nil)
+        (flycheck-mode))
+    (message "`lsp' layer is not installed, please add `lsp' layer to your dotfile.")))
--- a/layers/+lang/java/packages.el
+++ b/layers/+lang/java/packages.el
@ -29,6 +29,7 @@
        maven-test-mode
        (meghanada :toggle (not (version< emacs-version "25.1")))
        mvn
+        (lsp-java :requires lsp-mode lsp-ui company-lsp)
        org
        ))

@ -428,6 +429,46 @@

        "x:" 'meghanada-run-task))))

+(defun java/init-lsp-java ()
+  (use-package lsp-java
+    :defer t
+    :config
+    (progn
+      ;; key bindings
+      (dolist (prefix '(("mc" . "compile")
+                        ("mg" . "goto")
+                        ("mr" . "refactor")
+                        ("mq" . "lsp")))
+      (spacemacs/set-leader-keys-for-major-mode 'java-mode
+        "gg"  'xref-find-definitions
+        "gr"  'xref-find-references
+        "gR"  'lsp-ui-peek-find-references
+        "ga"  'xref-find-apropos
+        "gA"  'lsp-ui-peek-find-workspace-symbol
+        "gd"  'lsp-goto-type-definition
+        "hh"  'lsp-describe-thing-at-point
+        "el"  'lsp-ui-flycheck-list
+        "pu"  'lsp-java-update-user-settings
+        "ea"  'lsp-execute-code-action
+        "qr"  'lsp-restart-workspace
+        "roi" 'lsp-java-organize-imports
+        "rr" 'lsp-rename
+        "rai" 'lsp-java-add-import
+        "ram" 'lsp-java-add-unimplemented-methods
+        "rcp" 'lsp-java-create-parameter
+        "rcf" 'lsp-java-create-field
+        "rec" 'lsp-java-extract-to-constant
+        "rel" 'lsp-java-extract-to-local-variable
+        "rem" 'lsp-java-extract-method
+        "cc"  'lsp-java-build-project
+        "an"  'lsp-java-actionable-notifications
+        "="   'lsp-format-buffer)
+
+      (setq lsp-highlight-symbol-at-point nil
+            lsp-ui-sideline-update-mode 'point
+            lsp-eldoc-render-all nil
+            lsp-java-completion-guess-arguments t)))))
+
 (defun java/init-mvn ()
  (use-package mvn
    :defer t