Java Utililty Methods Zip Folder

if (!root.isDirectory())
    throw new IOException("Zip root must be a folder");
File zipFile = File.createTempFile("module-doc", ".zip");
try {
    ZipOutputStream os = new ZipOutputStream(new FileOutputStream(zipFile));
    try {
        for (File f : root.listFiles())
            zipInternal("", f, os);
...

if (root == null)
    return null;
if (!root.isDirectory())
    return null;
File out = File.createTempFile("SHA", null);
ZipOutputStream os = new ZipOutputStream(new BufferedOutputStream(new FileOutputStream(out)));
addFolder("", root, os);
os.flush();
...

if (!source.isDirectory()) {
    throw new IOException("Source must be folder.");
if (destination.exists()) {
    throw new IOException("Destination already exists.");
ZipOutputStream zipOutputStream = new ZipOutputStream(
        new BufferedOutputStream(new FileOutputStream(destination)));
...

destZipFile.getParentFile().mkdirs();
FileOutputStream fileWriter = new FileOutputStream(destZipFile);
ZipOutputStream zip = new ZipOutputStream(fileWriter);
if (zipOnlySrcFolderContentsAndNotSrcFolder) {
    for (File file : srcFolder.listFiles()) {
        addFileToZip("", file, zip, false);
} else {
...

final File file = new File(srcFolder, destZipFile);
final ZipOutputStream zip = new ZipOutputStream(new BufferedOutputStream(new FileOutputStream(file)));
try {
    addFolderToZip("", srcFolder, zip, destZipFile);
} finally {
    zip.close();
return file;
...

if (!"".equals(path)) {
    out.putNextEntry(new ZipEntry(path));
final File[] filesToAdd = directory.listFiles(new FileFilter() {
    @Override
    public boolean accept(final File file) {
        return file.isFile();
});
if (filesToAdd != null) {
    final byte data[] = new byte[DEFAULT_BUFFER_SIZE];
    BufferedInputStream origin = null;
    for (final File f : filesToAdd) {
        out.putNextEntry(new ZipEntry(path + f.getName()));
        final FileInputStream fi = new FileInputStream(f);
        origin = new BufferedInputStream(fi, DEFAULT_BUFFER_SIZE);
        int count;
        while ((count = origin.read(data, 0, DEFAULT_BUFFER_SIZE)) != -1) {
            out.write(data, 0, count);
        origin.close();
final File[] directoriesToAdd = directory.listFiles(new FileFilter() {
    @Override
    public boolean accept(final File file) {
        return file.isDirectory();
});
if (directoriesToAdd != null) {
    for (final File dir : directoriesToAdd) {
        zipFolder(dir, path + File.separator + dir.getName() + File.separator, out);

ZipOutputStream outZip = null;
try {
    outZip = new ZipOutputStream(out);
    addFolderToZip("", srcFolder, outZip);
} finally {
    if (outZip != null) {
        try {
            outZip.close();
...

try {
    final FileOutputStream fileWriter = new FileOutputStream(destZipFile);
    final ZipOutputStream zip = new ZipOutputStream(fileWriter);
    addFolderToZip("", srcFolder, zip);
    zip.flush();
    zip.close();
} catch (Exception e) {
    e.printStackTrace();
...

FileOutputStream fos = new FileOutputStream(destDir + "/" + name + ".zip");
ZipOutputStream zipOut = new ZipOutputStream(fos);
File fileToZip = new File(sourceDir);
zipFile(fileToZip, fileToZip.getName(), zipOut);
zipOut.close();
fos.close();

List<String> fileList = generateFileList(sourceFolder, new File(sourceFolder));
byte[] buffer = new byte[1024];
FileOutputStream fos = null;
ZipOutputStream zos = null;
try {
    fos = new FileOutputStream(target);
    zos = new ZipOutputStream(fos);
    FileInputStream in = null;
...