How can I manually install and set up the checkstyle linter for Vim and ALE?

[TheButterflyMon]

I'm trying to lint *.java files with Vim and ALE. It works fine when I use javac as the linter, but I would like to use checkstyle. I added the following to my .vimrc to tell ALE to only use the checkstyle linter for *.java files:

 " for Java files, use 'checkstyle' (and only checkstyle)
 let g:ale_linters = {
       \ 'java': ['checkstyle'],
       \ }

I have an old MacBook with OSX Yosemite, so I cannot use Homebrew to download and install checkstyle as some of the required components (like Go) will not install on my machine. I downloaded checkstyle-9.3-all.jar, renamed it to checkstyle.jar, and put it in a folder /XXX/checkstyle/checkstyle.jar. Then, I updated the $CLASSPATH and $PATH variables in my .profile:

export CLASSPATH=/XXX/checkstyle/checkstyle.jar:$CLASSPATH
export PATH=/XXX/checkstyle:$PATH

Finally, I updated the global variable g:ale_java_checkstyle_executable in my .vimrc:

" see :help g:ale_java_checkstyle_config
let g:ale_java_checkstyle_executable = 'checkstyle.jar'

I can use checkstyle from the command line with java com.puppycrawl.tools.checkstyle.Main ( java com.puppycrawl.tools.checkstyle.Main --help shows me the help screen ). I can also display the help information with java -jar checkstyle.jar --help. But for some reason, I have to invoke that command from the folder which contains checkstyle.jar; otherwise I get an Error: Error: Unable to access jarfile checkstyle.jar.

However, ALE's linting does not work with checkstyle. I searched all over the Internet and tried many different variations, but nothing worked. I've attached a screenshot of the :ALEInfo command. If anyone knows what I am doing wrong, any help is appreciated.

[hsanson]

ALE requires a binary called "checkstyle" to be present on your PATH in order to find it and use it. Simplest way to get it to work on your environment is to create an executable bash script named "checkstyle" that calls whatever command needed to run the jar:

#!/bin/sh

java -jar /path/to/checkstyle.jar com.puppycrawl.tools.checkstyle.Main "$@"

Copy the bash script into your path (e.g. /usr/local/bin/checkstyle) and make it executable (e.g. chmod +x /usr/local/bin/checkstyle). Note you will have to ensure the script accepts and passes any arguments directly (e..g "$@").

[TheButterflyMon]

Thank you. That works perfectly!