Java Utililty Methods Folder Read

List<File> fileList = new LinkedList<File>();
for (File folder : folders) {
    if (folder.isDirectory()) {
        for (File f : folder.listFiles()) {
            if (f.isDirectory())
                fileList.addAll(getFiles(f));
            else
                fileList.add(f);
...

Map<String, byte[]> files = new LinkedHashMap<>(); 
try (ZipFile apkZip = new ZipFile(apkFile)) {
    Enumeration<? extends ZipEntry> zipEntries = apkZip.entries();
    while (zipEntries.hasMoreElements()) {
        ZipEntry zipEntry = zipEntries.nextElement();
        if (regex.matcher(zipEntry.getName()).matches()) {
            try (InputStream is = new BufferedInputStream(apkZip.getInputStream(zipEntry))) {
                files.put(zipEntry.getName(), ByteStreams.toByteArray(is));
...

ZipFile zip = new ZipFile(archive);
List<String> result = new ArrayList<>(zip.size());
try {
    Enumeration<? extends ZipEntry> entries = zip.entries();
    while (entries.hasMoreElements()) {
        ZipEntry entry = entries.nextElement();
        result.add(entry.getName());
} finally {
    zip.close();
return result;

if (!dir.isDirectory()) {
    throw new IllegalArgumentException();
Vector files = new Vector();
String[] list = dir.list();
if ((list != null) && (list.length != 0)) {
    int len = list.length;
    for (int i = 0; i < len; i++) {
...

List<File> list = new LinkedList<File>();
getAllFilesRecursively(dir, list);
File[] arr = new File[list.size()];
list.toArray(arr);
return arr;

if (dir.isFile())
    throw new IOException("BadInputException: not a directory.");
if (!dir.exists()) {
    throw new IOException(" don't exist ");
File[] files = dir.listFiles();
return files;

List<String> result = new ArrayList<String>();
File[] aFiles = dir.listFiles();
List<File> files = Arrays.asList(aFiles);
for (File file : files) {
    boolean exclude = false;
    for (File f : excludes) {
        if (file.getAbsolutePath().startsWith(f.getAbsolutePath())) {
            exclude = true;
...

return getFiles(dir, pattern, null);

StringBuilder builder = new StringBuilder();
File[] files = dir.listFiles();
if (files != null) {
    if (names.length > 0) {
        for (File file : files) {
            for (String name : names) {
                if (file.getName().startsWith(name)) {
                    append(file.getPath(), builder);
...

if (directory == null || !directory.isDirectory()) {
    return null;
return directory.listFiles();