I broke up with neovim....vim is my best friend now

dot_vim/plugged/ale/ale_linters/java/checkstyle.vim

@@ -0,0 +1,73 @@
+" Author: Devon Meunier <devon.meunier@gmail.com>
+" Description: checkstyle for Java files
+
+call ale#Set('java_checkstyle_executable', 'checkstyle')
+call ale#Set('java_checkstyle_config', '/google_checks.xml')
+call ale#Set('java_checkstyle_options', '')
+
+function! ale_linters#java#checkstyle#Handle(buffer, lines) abort
+    let l:output = []
+
+    " modern checkstyle versions
+    let l:pattern = '\v\[(WARN|ERROR)\] [a-zA-Z]?:?[^:]+:(\d+):(\d+)?:? (.*) \[(.+)\]'
+
+    for l:match in ale#util#GetMatches(a:lines, l:pattern)
+        call add(l:output, {
+        \   'type': l:match[1] is? 'WARN' ? 'W' : 'E',
+        \   'sub_type': 'style',
+        \   'lnum': l:match[2] + 0,
+        \   'col': l:match[3] + 0,
+        \   'text': l:match[4],
+        \   'code': l:match[5],
+        \})
+    endfor
+
+    if !empty(l:output)
+        return l:output
+    endif
+
+    " old checkstyle versions
+    let l:pattern = '\v(.+):(\d+): ([^:]+): (.+)$'
+
+    for l:match in ale#util#GetMatches(a:lines, l:pattern)
+        call add(l:output, {
+        \   'type': l:match[3] is? 'warning' ? 'W' : 'E',
+        \   'sub_type': 'style',
+        \   'lnum': l:match[2] + 0,
+        \   'text': l:match[4],
+        \})
+    endfor
+
+    return l:output
+endfunction
+
+function! s:GetConfig(buffer, config) abort
+    if ale#path#IsAbsolute(a:config)
+        return a:config
+    endif
+
+    let s:file = ale#path#FindNearestFile(a:buffer, a:config)
+
+    return !empty(s:file) ? s:file : a:config
+endfunction
+
+function! ale_linters#java#checkstyle#GetCommand(buffer) abort
+    let l:options = ale#Var(a:buffer, 'java_checkstyle_options')
+    let l:config_option = ale#Var(a:buffer, 'java_checkstyle_config')
+    let l:config = l:options !~# '\v(^| )-c ' && !empty(l:config_option)
+    \   ? s:GetConfig(a:buffer, l:config_option)
+    \   : ''
+
+    return '%e'
+    \ . ale#Pad(l:options)
+    \ . (!empty(l:config) ? ' -c ' . ale#Escape(l:config) : '')
+    \ . ' %s'
+endfunction
+
+call ale#linter#Define('java', {
+\   'name': 'checkstyle',
+\   'executable': {b -> ale#Var(b, 'java_checkstyle_executable')},
+\   'command': function('ale_linters#java#checkstyle#GetCommand'),
+\   'callback': 'ale_linters#java#checkstyle#Handle',
+\   'lint_file': 1,
+\})