Java Utililty Methods File Copy nio

File tempFile = File.createTempFile(prefix, suffix);
tempFile.deleteOnExit();
copy(in, new FileOutputStream(tempFile));
return tempFile;

if (destination.exists()) {
    throw new IllegalArgumentException("Cannot overwrite existing file");
FileChannel sourceChannel = null, destChannel = null;
try {
    sourceChannel = new FileInputStream(source).getChannel();
    destChannel = new FileOutputStream(destination).getChannel();
    destChannel.transferFrom(sourceChannel, 0, sourceChannel.size());
...

if (!target.getParentFile().exists()) {
    target.getParentFile().mkdirs();
Files.copy(new FileInputStream(source.getAbsolutePath().replace("%20", " ")), target.toPath(),
        StandardCopyOption.REPLACE_EXISTING);

FileChannel source = null;
FileChannel destination = null;
FileInputStream fis = null;
FileOutputStream fos = null;
try {
    fis = new FileInputStream(sourceFile);
    fos = new FileOutputStream(destFile);
    source = fis.getChannel();
...

if (!dest.exists()) {
    final File parent = new File(dest.getParent());
    if (!parent.exists() && !parent.mkdirs()) {
        throw new IOException();
    if (!dest.exists() && !dest.createNewFile()) {
        throw new IOException();
try (final FileInputStream is = new FileInputStream(src);
        final FileOutputStream os = new FileOutputStream(dest);
        final FileChannel srcChannel = is.getChannel();
        final FileChannel dstChannel = os.getChannel()) {
    dstChannel.transferFrom(srcChannel, 0, srcChannel.size());

FileInputStream in = null;
FileOutputStream out = null;
try {
    in = new FileInputStream(src);
    out = new FileOutputStream(dest);
    FileChannel fcin = in.getChannel();
    FileChannel fcout = out.getChannel();
    long bytes = fcin.size();
...