import java.io.FileInputStream; import java.io.FileOutputStream; import java.nio.channels.FileChannel; public class MainClass { public static void main(String[] args) throws Exception { FileChannel in = new FileInputStream("source.txt").getChannel(), out = new FileOutputStream( "target.txt").getChannel(); in.transferTo(0, in.size(), out); // Or: // out.transferFrom(in, 0, in.size()); } }