Java Utililty Methods FileChannel Copy

if (source != null && dest != null && source.isDirectory() && dest.isDirectory()) {
    String[] children = source.list();
    for (String child : children) {
        File in = new File(source, child);
        File out = new File(dest, child);
        if (in.isDirectory()) {
            out.mkdir();
            copyTree(in, out);
...

ReadableByteChannel inChannel = Channels.newChannel(in.openStream());
FileChannel outChannel = new FileOutputStream(out).getChannel();
try {
    outChannel.transferFrom(inChannel, 0, 1 << 24);
} catch (IOException e) {
    throw e;
} finally {
    if (inChannel != null)
...

File sourceFile = new File(src);
File destFile = new File(dest);
copyUsingNIO(sourceFile, destFile);

ensureTargetDirectoryExists(aTargetFile.getParentFile());
FileChannel inChannel = null;
FileChannel outChannel = null;
FileInputStream inStream = null;
FileOutputStream outStream = null;
try {
    try {
        inStream = new FileInputStream(aSourceFile);
...

checkCanCopy(source, destination);
source = getFileURL(source);
destination = getFileURL(destination);
File dstFile = new File(destination.getFile());
if (!dstFile.exists() && !dstFile.mkdir()) {
    return;
if ("file".equals(source.getProtocol())) {
...

File[] files = srcDir.listFiles();
if (files == null) { 
    throw new IOException("Failed to list contents of " + srcDir);
if (destDir.exists()) {
    if (destDir.isDirectory() == false) {
        throw new IOException("Destination '" + destDir + "' exists but is not a directory");
} else {
    if (destDir.mkdirs() == false) {
        throw new IOException("Destination '" + destDir + "' directory cannot be created");
if (destDir.canWrite() == false) {
    throw new IOException("Destination '" + destDir + "' cannot be written to");
for (File file : files) {
    File copiedFile = new File(destDir, file.getName());
    if (exclusionList == null || !exclusionList.contains(file.getCanonicalPath())) {
        if (file.isDirectory()) {
            doCopyDirectory(file, copiedFile, preserveFileDate, exclusionList);
        } else {
            doCopyFile(file, copiedFile, preserveFileDate);
if (preserveFileDate) {
    destDir.setLastModified(srcDir.lastModified());

if (destFile.exists() && destFile.isDirectory()) {
    throw new IOException("Destination '" + destFile + "' exists but is a directory");
FileInputStream fis = null;
FileOutputStream fos = null;
FileChannel input = null;
FileChannel output = null;
try {
...

if (destFile.exists() && destFile.isDirectory()) {
    throw new IOException("Destination '" + destFile + "' exists but is a directory");
FileChannel input = new FileInputStream(srcFile).getChannel();
try {
    FileChannel output = new FileOutputStream(destFile).getChannel();
    try {
        output.transferFrom(input, 0, input.size());
...

if (null == src || null == dest) {
FileChannel srcChannel = src.getChannel();
FileChannel dstChannel = new FileOutputStream(dest).getChannel();
dstChannel.transferFrom(srcChannel, 0, srcChannel.size());
srcChannel.close();
dstChannel.close();

FileInputStream fi = null;
FileOutputStream fo = null;
FileChannel in = null, out = null;
try {
    fi = new FileInputStream(src);
    fo = new FileOutputStream(dest);
    in = fi.getChannel();
    out = fo.getChannel();
...