Java Utililty Methods File List Load

if (dir == null || !dir.exists())
    return;
list.add(dir);
if (dir.isFile()) {
    return;
File[] files = dir.listFiles();
if (files == null)
...

return getFileList(dir, null, arrayList);

ArrayList<String> fileList = new ArrayList<String>();
File[] fs = dir.listFiles();
for (int i = 0; i < fs.length; i++) {
    if (fs[i].isDirectory()) {
        fileList.addAll(getFileList(fs[i], regex));
    } else if (fs[i].isFile() && fs[i].getName().endsWith(regex)) {
        fileList.add(fs[i].getAbsolutePath());
return fileList;

File[] subFiles = dirFile.listFiles(new FilenameFilter() {
    @Override
    public boolean accept(File dir, String name) {
        File f = new File(dir + File.separator + name);
        return f.isFile() && name.startsWith(filenamePrefix);
});
return subFiles;
...

List<File> fileList = new ArrayList<File>();
File[] files = f.listFiles();
if (files != null) {
    for (File file : files) {
        if (!file.isDirectory())
            fileList.add(file);
return fileList;

final File[] files = f.listFiles(filter);
if (files != null) {
    for (File file : files) {
        if ((!file.isHidden()) || wantHidden) {
            if (file.isDirectory()) {
                if (wantDirectory)
                    list.add(file);
                if (recursive)
...

if (file.isFile() && !file.isDirectory()) {
    return new File[] { file };
return file.listFiles() != null ? file.listFiles() : new File[0];

return getFileList(file, true);

return getFileList(file, new ArrayList<File>(), suffixs, null, null);

List<File> fileNameList = new ArrayList<File>();
File[] files = folder.listFiles();
for (File file : files) {
    if (getFileType(file).equalsIgnoreCase(type)) {
        fileNameList.add(file);
return fileNameList;
...