插件中的Jenkins FileSystem是什么？

Question

I have a class that passes tests fine, and runs if I invoke it in a separate Java class outside of Jenkins. It's constructor has this:

this.fs = FileSystems.getDefault();

Later on in execution, I added a sanity check after seeing a null pointer exception.

if (this.fs == null) {
  throw new Exception("No FileSystem found");
}

So when this plugin runs in Jenkins, the default FileSystem is null and that exception is thrown. My original code used Paths.get but I had switched it to this.fs.getPath(stringPath); so I can use DI to create a FileSystem for unit tests.

Using Paths.get had worked fine before refactor, but I'm not sure how using that method knew the correct FileSystem , especially given the default doesn't seem to be set in this environment.

Answer 1

Never heard of such a problem. Sounds like your environment is badly broken, since this is defined by the Java Platform. Try bisecting—incrementally remove noncritical pieces of your plugin until you figure out which is triggering the issue.

Answer 2

After using System.out , I realized the constructor doesn't run on plugin update. It does run when saving job config. So when I saved job config, this fixed my issue via side effect. I wasn't setting this.fs originally, so updating the plugin didn't run those new lines. So I shouldn't be putting things into the constructor that won't be used for configuration. In hindsight this makes sense cause it's really a @DataBoundConstructor which implies it's being used for the data from config.