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Copy a File in Java

Copying a file or directory used to be a typical development task. It’s a fundamental concept, and it might be useful to know what options does the Java developers have when they need to copy a file. Read more about Java IO classes to see available options for reading and writing files.

I/O Streams

the standard way to copy a file was by utilizing I/O Streams:

private void copyFile(File src, File dest) throws IOException {
    InputStream inputStream = null;
    OutputStream outputStream = null;
    try {
        inputStream = new FileInputStream(source);
        outputStream = new FileOutputStream(dest);

        // the size of the buffer doesn't have to be exactly 1024 bytes,
        // try playing around with this number and see what effect
        // it will have on the performance
        byte[] buffer = new byte[1024];
        int length = 0;
        while ((length = > 0) {
            os.write(buffer, 0, length);
    } finally {

Channels and java.nio

Using a classes from java.nio package:

private void copyFileUsingChannel(File src, File dest) throws IOException {
    FileChannel sourceChannel = null;
    FileChannel destinationChannel = null;
    try {
        sourceChannel = new FileInputStream(src).getChannel();
        destinationChannel = new FileOutputStream(dest).getChannel();
        destinationChannel.transferFrom(sourceChannel, 0, sourceChannel.size());
       } finally {

Files Helper Class

Using java.nio.Files class which consists exclusively of static methods that operate on files, directories, or other types of files. Take a look at the API documentation to read more and see available options to the copy() method:

private static void copyFile(File src, File dest) throws IOException {
    Files.copy(src.toPath(), dest.toPath());