NIO

File file = new File("C:\\Users\\dailei\\Desktop\\test\\1.txt");
		File file2 = new File("C:\\Users\\dailei\\Desktop\\test\\4.txt");
		try {
			FileChannel inChannel = new FileInputStream(file).getChannel();
			FileChannel outChannel = new FileOutputStream(file2).getChannel();
			ByteBuffer cb = ByteBuffer.allocate(64);
			while((inChannel.read(cb)) != -1) {
				cb.flip();
				outChannel.write(cb);
				cb.clear();
			}
			
		}catch(IOException e) {
			e.printStackTrace();
		}