JGit and finding the Head

Question

I\'m trying to get my hands on the HEAD commit with JGit:

val builder = new FileRepositoryBuilder()
val repo = builder.setGitDir(new File(\"/www/test-repo\")         


        

Answer 1

You can also use val git: Git = Git.open( new File( "/www/test-repo" ) ). JGit will then scan the given folder for the git meta directory (usually .git). If it fails to find this folder, an IOException will be thrown.

Answer 2

You need to point to the Git metadata directory (probably /www/test-repo/.git) when you call setGitDir, not to the working directory (/www/test-repo).

I have to admit I'm not sure what findGitDir is supposed to do, but I've run into this problem before and specifying the .git directory worked.

Answer 3

For the completeness sake, here is a fully working example how to get the hash for the HEAD commit:

public String getHeadName(Repository repo) {
  String result = null;
  try {
    ObjectId id = repo.resolve(Constants.HEAD);
    result = id.getName();
  } catch (IOException e) {
    e.printStackTrace();
  }
  return result;
}

Answer 4

For me (using 4.5.0.201609210915-r) the solution was to use just RepositoryBuilder instead of FileRepositoryBuilder. Until I made this change all methods were returning null.

rb = new org.eclipse.jgit.lib.RepositoryBuilder()
    .readEnvironment()
    .findGitDir()
    .build();

headRef = rb.getRef(rb.getFullBranch());
headHash = headRef.getObjectId().name();