Merge pull request #2121 from hsanson/1996-add-support-for-eclipse-jdt-ls

WIP Fix 1996 - Add eclipse LSP support.

doc/ale-java.txt

@@ -101,6 +101,39 @@ g:ale_java_javalsp_executable                   *g:ale_java_javalsp_executable*
 This variable can be changed to use a different executable for java.
 
 
+===============================================================================
+eclipselsp                                                *ale-java-eclipselsp*
+
+To enable Java LSP linter you need to clone and build the eclipse.jdt.ls
+language server from https://github.com/eclipse/eclipse.jdt.ls. Simply
+clone the source code repo and then build the plugin:
+
+   ./mvnw clean verify
+
+Note: currently, the build can only run when launched with JDK 8. JDK 9 or more
+recent versions can be used to run the server though.
+
+After build completes the files required to run the language server will be
+located inside the folder |org.eclipse.jdt.ls.product/target/repository|.
+Ensure to set |g:ale_java_eclipselsp_path| to the absolute path of that folder.
+
+g:ale_java_eclipselsp_path                         *g:ale_java_eclipselsp_path*
+                                                   *b:ale_java_eclipselsp_path*
+
+  Type: |String|
+  Default: `'eclipse.jdt.ls/org.eclipse.jdt.ls.product/target/repository'`
+
+  Path to the location of the eclipse.jdt.ls product repository.
+
+
+g:ale_java_eclipselsp_executable                *g:ale_java_eclipse_executable*
+                                                *b:ale_java_eclipse_executable*
+  Type: |String|
+  Default: `'java'`
+
+  This variable can be set to change the executable path used for java.
+
+
 ===============================================================================
 uncrustify                                                *ale-java-uncrustify*
 

doc/ale-supported-languages-and-tools.txt

@@ -200,6 +200,7 @@ Notes:
   * `ispc`!!
 * Java
   * `checkstyle`
+  * `eclipselsp`
   * `google-java-format`
   * `javac`
   * `javalsp`

doc/ale.txt

@@ -1987,6 +1987,7 @@ documented in additional help files.
     google-java-format....................|ale-java-google-java-format|
     pmd...................................|ale-java-pmd|
     javalsp...............................|ale-java-javalsp|
+    eclipselsp............................|ale-java-eclipselsp|
     uncrustify............................|ale-java-uncrustify|
   javascript..............................|ale-javascript-options|
     eslint................................|ale-javascript-eslint|