使用FileChannel写入任何InputStream？

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.channels.FileChannel;

public class InputStreamToFileChannel {
    public static void main(String[] args) {
        String inputFile = "input.txt";
        String outputFile = "output.txt";
        try {
            FileInputStream fis = new FileInputStream(inputFile);
            FileOutputStream fos = new FileOutputStream(outputFile);
            FileChannel inputChannel = fis.getChannel();
            FileChannel outputChannel = fos.getChannel();
            outputChannel.transferFrom(inputChannel, 0, inputChannel.size());
            inputChannel.close();
            outputChannel.close();
            fis.close();
            fos.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}