jGit 针对单个文件比较这个文件最新的 commit

1. jGit 针对单个文件比较这个文件最新的 commit

path 为文件路径

private static List<DiffEntry> diff(String path) throws GitAPIException, IOException {
        try (Repository repository = RepositoryUtil.getRepository()) {
            try (Git git = new Git(repository)) {
                Iterable<RevCommit> commits = git.log()
                        .addPath(path)
                        .call();
                RevCommit latestCommit =
                        StreamSupport.stream(commits.spliterator(), false)
                        .reduce((c1, c2) -> c1.getCommitTime() > c2.getCommitTime() ? c1 : c2)
                        .orElseThrow(NullPointerException::new);
                AbstractTreeIterator oldTreeParser = TreeParserUtil.parser(repository, latestCommit.name());
                return git.diff()
                        .setOldTree(oldTreeParser)
                        .setPathFilter(PathFilter.create(path))
                        .call();
            }
        }
    }

2. 如果你想对 git diff 的结果进行输出

有两种办法：

2.1 对结果 DiffEntry 进行输出

public static void printDiff(DiffEntry entries){
        DiffFormatter diffFormatter = new DiffFormatter(System.out);
        try {
            diffFormatter.setRepository(RepositoryUtil.getRepository());
            diffFormatter.format(entries);
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            diffFormatter.close();
        }
    }

2.2 在进行 git.diff()方法调用的时候再调用.setOutputStream(System.out)

就像这样，当然传入的参数不止可以是 System.out,只要是 OutputStream 就行

return git.diff().setOutputStream(System.out)
                        .setOldTree(oldTreeParser)
                        .setPathFilter(PathFilter.create(path))
                        .call();