问题
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;
}
and is later updated to
int test(){
return 7;
}
I currently have a method which uses the JGit API in order to access the Git repository where the above are committed and outputs a string which is similar to the following:
int test(){
-int a = 3;
-int b = 4;
-int c = a + b;
-return c;
+return 7;
}
Now, my requirements have changed and would like to know the line numbers of the changed lines only. So I would want something like the following:
2 -int a = 3;
3 -int b = 4;
4 -int c = a + b;
5 -return c;
2 +return 7;
Basically, the same information that the GitHub application gives when an update is made.
Any help would be greatly appreciated :)
snippet of how the -/+ lines are computed:
String oldHash = "ee3e216ab5047748a22e9ec5ad3e92834704f0cc";
Git git = null;
try {
//the path where the repo is.
git = Git.open(new File("C:\\Users\\Administrator\\Documents\\GitHub\\Trial"));
} catch (IOException e1) {
e1.printStackTrace();
}
Repository repository = git.getRepository();
ObjectId old = null;
ObjectId head = null;
//a new reader to read objects from getObjectDatabase()
ObjectReader reader = repository.newObjectReader();
//Create a new parser.
CanonicalTreeParser oldTreeIter = new CanonicalTreeParser();
CanonicalTreeParser newTreeIter = new CanonicalTreeParser();
List<DiffEntry> diffs = null;
try {
//parse a git repository string and return an ObjectId
old = repository.resolve(oldHash + "^{tree}");
head = repository.resolve("HEAD^{tree}");
//Reset this parser to walk through the given tree
oldTreeIter.reset(reader, old);
newTreeIter.reset(reader, head);
diffs = git.diff()//Returns a command object to execute a diff command
.setNewTree(newTreeIter)
.setOldTree(oldTreeIter)
.call();//returns a DiffEntry for each path which is different
} catch (RevisionSyntaxException | IOException | GitAPIException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//DiffLineCountFilter d = new DiffLineCountFilter();
//out is the stream the formatter will write to
ByteArrayOutputStream out = new ByteArrayOutputStream();
//Create a new formatter with a default level of context.
DiffFormatter df = new DiffFormatter(out);
//Set the repository the formatter can load object contents from.
df.setRepository(git.getRepository());
ArrayList<String> diffText = new ArrayList<String>();
//A DiffEntry is 'A value class representing a change to a file' therefore for each file you have a diff entry
for(DiffEntry diff : diffs)
{
try {
//Format a patch script for one file entry.
df.format(diff);
RawText r = new RawText(out.toByteArray());
r.getLineDelimiter();
diffText.add(out.toString());
out.reset();
} catch (IOException e) {
e.printStackTrace();
}
}
回答1:
Just a tip for anyone who might have this problem. I did not manage to get the line numbers of the added and deleted lines but I did manage to get a string which contains only the added and deleted lines without the other lines which were not changed.
This was simply done by adding the line:
df.setContext(0);
in the snippet I provided above right before the line
df.format(diff);
回答2:
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<DiffEntry> 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);
}
回答3:
I do it this way but I don't know if it is correct
public void linesChangeInFile(Git git, List<RevCommit> commits, String fileName, String pathRepository) {
try {
List<RevCommit> commitsComparer = new ArrayList<>();
List<String> linesChange = new ArrayList<>();
for (int i = 0; i < commits.size() - 1; i++) {
ObjectId commitIDOld = commits.get(i).getId();
if (Validador.isFileExistInCommit(commits.get(i), getRepository(), fileName)) {
if (i != commits.size() - 1 && !commitsComparer.contains(commits.get(i))) {
ObjectId commitIDNew = commits.get(i + 1);
commitsComparer.add(commits.get(i));
linesChange.add(diff(git, commitIDOld.getName(), commitIDNew.getName(), fileName));
}
try (final FileInputStream input = new FileInputStream(pathRepository + "\\" + fileName)) {
currentLines = IOUtils.readLines(input, "UTF-8").size();
}
}
}
Integer sumLinesAdd = 0;
Integer sumLinesDel = 0;
for (String lineChange : linesChange) {
String[] lChange = lineChange.split(";");
sumLinesAdd += Integer.parseInt(lChange[0]);
sumLinesDel += Integer.parseInt(lChange[1]);
}
System.out.println("Lines Add total:" + sumLinesAdd);
System.out.println("Lines Del total:" + sumLinesDel);
System.out.println("Total lines change:" + (sumLinesAdd + sumLinesDel));
} catch (RevisionSyntaxException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private String diff(Git git, String commitIDOld, String commitIDNew, String fileName) {
int linesAdded = 0;
int linesDeleted = 0;
DiffFormatter df = null;
try {
AbstractTreeIterator oldTreeParser = prepareTreeParser(getRepository(), commitIDOld);
AbstractTreeIterator newTreeParser = prepareTreeParser(getRepository(), commitIDNew);
List<DiffEntry> diffs = git.diff().setOldTree(oldTreeParser).setNewTree(newTreeParser)
.setPathFilter(PathFilter.create(fileName)).call();
df = new DiffFormatter(DisabledOutputStream.INSTANCE);
df.setRepository(getRepository());
df.setDiffComparator(RawTextComparator.DEFAULT);
df.setDetectRenames(true);
for (DiffEntry entry : diffs) {
// System.out.println("Entry: " + entry + ", from: " + entry.getOldId() + ", to:
// " + entry.getNewId());
// try (DiffFormatter formatter = new DiffFormatter(System.out)) {
// formatter.setContext(0);
// formatter.setRepository(repository);
// formatter.format(entry);
// }
for (Edit edit : df.toFileHeader(entry).toEditList()) {
linesDeleted += edit.getEndA() - edit.getBeginA();
linesAdded += edit.getEndB() - edit.getBeginB();
}
}
} catch (IOException | GitAPIException e) {
System.err.println("Error:" + e.getMessage());
}
return linesAdded + ";" + linesDeleted;
}
来源：https://stackoverflow.com/questions/19467305/using-the-jgit-how-can-i-retrieve-the-line-numbers-of-added-deleted-lines