Using the JGIT, how can I retrieve the line numbers of added/deleted lines

Question

Assuming the following piece of code is committed to a Git repository:

int test(){
   int a = 3;
   int b = 4;
   int c = a + b;
   return c;
}

Answer 1

You need to do the difference between the A line indexes and B line indexes from the diff result:

int linesAdded = 0;
int linesDeleted = 0;
int filesChanged = 0;
try {
    repo = new FileRepository(new File("repo/.git"));
    RevWalk rw = new RevWalk(repo);
    RevCommit commit = rw.parseCommit(repo.resolve("486817d67b")); // Any ref will work here (HEAD, a sha1, tag, branch)
    RevCommit parent = rw.parseCommit(commit.getParent(0).getId());
    DiffFormatter df = new DiffFormatter(DisabledOutputStream.INSTANCE);
    df.setRepository(repo);
    df.setDiffComparator(RawTextComparator.DEFAULT);
    df.setDetectRenames(true);
    List diffs;
    diffs = df.scan(parent.getTree(), commit.getTree());
    filesChanged = diffs.size();
    for (DiffEntry diff : diffs) {
        for (Edit edit : df.toFileHeader(diff).toEditList()) {
            linesDeleted += edit.getEndA() - edit.getBeginA();
            linesAdded += edit.getEndB() - edit.getBeginB();
        }
    }
} catch (IOException e1) {
    throw new RuntimeException(e1);
}