Create git repo with jgit and put a file into it

Question

I have the following code to generate a new git repo and put a .gitignore into it:

  Repository repo = new FileRepositoryBuilder().setGitDir(gitProjectDir.toFile())
        .setWorkTree(gitProjectDir.toFile())
        .build();
    repo.create();

    // Add a file from the resources to the repository
    try (Git git = new Git(repo))
    {
      Files.copy(Thread.currentThread()
          .getContextClassLoader()
          .getResourceAsStream("gitignore.txt"), gitProjectDir.resolve(".gitignore"),
          StandardCopyOption.REPLACE_EXISTING);

      try
      {
        git.add()
            .addFilepattern(".gitignore")
            .call();

        git.commit()
            .setAuthor("CMBUILD", "[email protected]")
            .setMessage(jiraTicket + ": Hinzufügen von .gitignore")
            .call();
      }
      catch (GitAPIException e)
      {
        throw new IOException(
            "Could not create the commit", e);
      }
    }

While this seems to work (if you clone the resulting repo, you get one commit that contains the .gitignore file), it also seems to be not quite correct because the git repo (not the clone!) that I generate looks like this:

Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
d-----        28.08.2023     11:22                branches
d-----        28.08.2023     11:22                hooks
d-----        28.08.2023     11:22                logs
d-----        28.08.2023     11:22                objects
d-----        28.08.2023     11:22                refs
-a----        28.08.2023     11:22            105 .git
-a----        28.08.2023     11:22           4505 .gitignore
-a----        28.08.2023     11:22             36 COMMIT_EDITMSG
-a----        28.08.2023     11:22            214 config
-a----        28.08.2023     11:22             23 HEAD
-a----        28.08.2023     11:22            112 index

So the .gitignore just lies within the repository files.

How can I adjust the code to avoid this?

Answer 1

You're using setGitDir incorrectly. From an archived version of the API I could find;

Set the Git directory storing the repository metadata.

In other words, you're telling jgit not to use the .git directory but instead use the project dir itself.