Standard concise way to copy a file in Java?

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I would avoid the use of a mega api like apache commons. This is a simplistic operation and its built into the JDK in the new NIO package. It was kind of already linked to in a previous answer, but the key method in the NIO api are the new functions “transferTo” and “transferFrom”.

http://java.sun.com/javase/6/docs/api/java/nio/channels/FileChannel.html#transferTo(long,%20long,%20java.nio.channels.WritableByteChannel)

One of the linked articles shows a great way on how to integrate this function into your code, using the transferFrom:

public static void copyFile(File sourceFile, File destFile) throws IOException {
    if(!destFile.exists()) {
        destFile.createNewFile();
    }

    FileChannel source = null;
    FileChannel destination = null;

    try {
        source = new FileInputStream(sourceFile).getChannel();
        destination = new FileOutputStream(destFile).getChannel();
        destination.transferFrom(source, 0, source.size());
    }
    finally {
        if(source != null) {
            source.close();
        }
        if(destination != null) {
            destination.close();
        }
    }
}

Learning NIO can be a little tricky, so you might want to just trust in this mechanic before going off and trying to learn NIO overnight. From personal experience it can be a very hard thing to learn if you don’t have the experience and were introduced to IO via the java.io streams.

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