I am trying to use JGit to get the differences of a file from the last commit to the most recent uncommitted changes. How can I do this with JGit? (using the command line would be the output of git diff HEAD)
Following several discussions (link1, link2) I come with a piece of code that is able to find the files that are uncommited, but it I cannot get the difference of the files
Repository db = new FileRepository("/path/to/git"); Git git = new Git(db); AbstractTreeIterator oldTreeParser = this.prepareTreeParser(db, Constants.HEAD); List<DiffEntry> diff = git.diff().setOldTree(oldTreeParser).call(); for (DiffEntry entry : diff) { System.out.println("Entry: " + entry + ", from: " + entry.getOldId() + ", to: " + entry.getNewId()); DiffFormatter formatter = new DiffFormatter(System.out); formatter.setRepository(db); formatter.format(entry); } UPDATE
This issue was a long time ago. My existing for does display the uncommitted code. The current code that I am using for prepareTreeParser, in the context of displaying the difference, is:
public void gitDiff() throws Exception { Repository db = new FileRepository("/path/to/git" + DEFAULT_GIT); Git git = new Git(db); ByteArrayOutputStream out = new ByteArrayOutputStream(); DiffFormatter formatter = new DiffFormatter( out ); formatter.setRepository(git.getRepository()); AbstractTreeIterator commitTreeIterator = prepareTreeParser(git.getRepository(), Constants.HEAD); FileTreeIterator workTreeIterator = new FileTreeIterator( git.getRepository() ); List<DiffEntry> diffEntries = formatter.scan( commitTreeIterator, workTreeIterator ); for( DiffEntry entry : diffEntries ) { System.out.println("DIFF Entry: " + entry + ", from: " + entry.getOldId() + ", to: " + entry.getNewId()); formatter.format(entry); String diffText = out.toString("UTF-8"); System.out.println(diffText); out.reset(); } git.close(); db.close(); // This code is untested. It is slighting different for the code I am using in production, // but it should be very easy to adapt it for your needs } private static AbstractTreeIterator prepareTreeParser(Repository repository, String ref) throws Exception { Ref head = repository.getRef(ref); RevWalk walk = new RevWalk(repository); RevCommit commit = walk.parseCommit(head.getObjectId()); RevTree tree = walk.parseTree(commit.getTree().getId()); CanonicalTreeParser oldTreeParser = new CanonicalTreeParser(); ObjectReader oldReader = repository.newObjectReader(); try { oldTreeParser.reset(oldReader, tree.getId()); } finally { oldReader.release(); } return oldTreeParser; }