private Map<String, BlobWrapper> getRevFileContentMap(
        Git git, RevCommit commit, Set<String> filePathSet, ObjectReader reader) throws Exception {
    if (filePathSet == null || filePathSet.isEmpty()) {
        return Collections.emptyMap();
    }
    TreeFilter filter = filePathSet.size() > 1
            ? OrTreeFilter.create(filePathSet.stream()
                    .map(PathFilter::create)
                    .collect(Collectors.toList()))
            : PathFilter.create(filePathSet.iterator().next());
     return getContentMapByTreeAndFilter(git, new CanonicalTreeParser(null, reader, commit.getTree()), filter);
}
 

private Map<String, BlobWrapper> getIndexedFileContentMap(Git git, Set<String> filePathSet) throws Exception {
    if (filePathSet == null || filePathSet.isEmpty()) {
        return Collections.emptyMap();
    }
    DirCache index = git.getRepository().readDirCache();
    TreeFilter filter = filePathSet.size() > 1
            ? OrTreeFilter.create(filePathSet.stream()
                    .map(PathFilter::create)
                    .collect(Collectors.toList()))
            : PathFilter.create(filePathSet.iterator().next());
    return getContentMapByTreeAndFilter(git, new DirCacheIterator(index), filter);
}
 

public static TreeFilter getExcludeExactPathsFilter (File workDir, File[] roots) {
    Collection<String> relativePaths = getRelativePaths(workDir, roots);
    TreeFilter filter = null;
    if (relativePaths.size() > 0) {
        Collection<PathFilter> filters = getPathFilters(relativePaths);
        List<TreeFilter> exactPathFilters = new LinkedList<TreeFilter>();
        for (PathFilter f : filters) {
            exactPathFilters.add(ExactPathFilter.create(f));
        }
        return NotTreeFilter.create(exactPathFilters.size() == 1 ? exactPathFilters.get(0) : OrTreeFilter.create(exactPathFilters));
    }
    return filter;
}