Improve eclipselsp jar search logic.

- Set default value to $HOME/eclipse.jdt.ls
 - Make JAR search regexp more specific.
 - Allow to set the VSCode extensions folder as ale_java_eclipselsp_path.

ale_linters/java/eclipselsp.vim

@@ -3,7 +3,7 @@
 
 let s:version_cache = {}
 
-call ale#Set('java_eclipselsp_path', 'eclipse.jdt.ls')
+call ale#Set('java_eclipselsp_path', ale#path#Simplify($HOME . '/eclipse.jdt.ls'))
 call ale#Set('java_eclipselsp_executable', 'java')
 
 function! ale_linters#java#eclipselsp#Executable(buffer) abort
@@ -16,20 +16,27 @@ endfunction
 
 function! ale_linters#java#eclipselsp#JarPath(buffer) abort
     let l:path = ale_linters#java#eclipselsp#TargetPath(a:buffer)
-    let l:path = l:path . '/org.eclipse.jdt.ls.product/target/repository/plugins'
 
-    let l:files = globpath(l:path, 'org.eclipse.equinox.launcher_*.jar', 1, 1)
+    " Search jar file within repository path when manually built using mvn
+    let l:repo_path = l:path . '/org.eclipse.jdt.ls.product/target/repository'
+    let l:files = globpath(l:repo_path, '**/plugins/org.eclipse.equinox.launcher_\d\.\d\.\d\d\d\.*\.jar', 1, 1)
 
-    if empty(l:files)
-        return ''
+    if len(l:files) == 1
+        return l:files[0]
     endif
 
-    return l:files[0]
+    " Search jar file within VSCode extensions folder.
+    let l:files = globpath(l:path, '**/plugins/org.eclipse.equinox.launcher_\d\.\d\.\d\d\d\.*\.jar', 1, 1)
+
+    if len(l:files) == 1
+        return l:files[0]
+    endif
+
+    return ''
 endfunction
 
 function! ale_linters#java#eclipselsp#ConfigurationPath(buffer) abort
-    let l:path = ale_linters#java#eclipselsp#TargetPath(a:buffer)
-    let l:path = l:path . '/org.eclipse.jdt.ls.product/target/repository'
+    let l:path = fnamemodify(ale_linters#java#eclipselsp#JarPath(a:buffer), ':p:h:h')
 
     if has('win32')
         let l:path = l:path . '/config_win'

doc/ale-java.txt

@@ -104,7 +104,7 @@ 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
+To enable Eclipse 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:
 
@@ -114,21 +114,23 @@ 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 repositoy folder `eclipse.jdt.ls`. Ensure to set
+located inside the repository folder `eclipse.jdt.ls`. Please ensure to set
 |g:ale_java_eclipselsp_path| to the absolute path of that folder.
 
 You could customize compiler options and code assists of the server.
-Under your project folder, modify the file
-`.settings/org.eclipse.jdt.core.prefs` with options presented at
+Under your project folder, modify the file `.settings/org.eclipse.jdt.core.prefs` 
+with options presented at
 https://help.eclipse.org/neon/topic/org.eclipse.jdt.doc.isv/reference/api/org/eclipse/jdt/core/JavaCore.html.
 
 g:ale_java_eclipselsp_path                         *g:ale_java_eclipselsp_path*
                                                    *b:ale_java_eclipselsp_path*
 
   Type: |String|
-  Default: `'eclipse.jdt.ls'`
+  Default: `'$HOME/eclipse.jdt.ls'`
 
-  Absolute path to the location of the eclipse.jdt.ls repository folder.
+  Absolute path to the location of the eclipse.jdt.ls repository folder. Or if
+  you have VSCode extension installed the absolute path to the VSCode extensions
+  folder (e.g. $HOME/.vscode/extensions in Linux).
 
 
 g:ale_java_eclipselsp_executable                *g:ale_java_eclipse_executable*

test/command_callback/test_eclipselsp_command_callback.vader

@@ -3,12 +3,12 @@ Before:
   let b:ale_java_eclipselsp_path = '/home/user/eclipse.dst.ls'
   call ale#test#SetFilename('dummy.java')
 
-  let b:cfg = '/home/user/eclipse.dst.ls/org.eclipse.jdt.ls.product/target/repository/config_linux'
+  let b:cfg = '/testplugin/test/config_linux'
 
   if has('win32')
-    let b:cfg = '\home\user\eclipse.dst.ls\org.eclipse.jdt.ls.product\target\repository\config_win'
+    let b:cfg = 'C:\testplugin\test\config_win'
   elseif has('macunix')
-    let b:cfg = '/home/user/eclipse.dst.ls/org.eclipse.jdt.ls.product/target/repository/config_mac'
+    let b:cfg = '/testplugin/test/config_mac'
   endif