import java.nio.*;
import java.nio.channels.*;
import java.io.*;

public class ChannelTest4 {
    private String[] texts = {"ABCDEFGHIJKLMNOPQRSTUVWXYZ",
                              "abcdefghijklmnopqrstuvwxyz",
                              "0123456789",
                              "あいうえお"};

    public ChannelTest4(String filename) {
        write(filename);
        read(filename);
    }

    public void write(String filename){
        try{
            FileOutputStream stream = new FileOutputStream(filename);
            FileChannel channel = stream.getChannel();
        
            ByteBuffer[] buffers = new ByteBuffer[texts.length];
            for(int i = 0 ; i < texts.length ; i++){
                buffers[i] = ByteBuffer.wrap(texts[i].getBytes());
            }

            channel.write(buffers, 1, 2);

            channel.close();
        }catch(FileNotFoundException ex){
            ex.printStackTrace();
        }catch(IOException ex){
            ex.printStackTrace();
        }
    }

    public void read(String filename){
        try{
            FileInputStream stream = new FileInputStream(filename);
            FileChannel channel = stream.getChannel();
        
            ByteBuffer[] buffers = new ByteBuffer[10];
            for (int i = 0 ; i < 10 ; i++){
                buffers[i] = ByteBuffer.allocate(10);
            }

            channel.read(buffers, 2, 3);

            for (int i = 0 ; i < 10 ; i++) {
                buffers[i].clear();
                byte[] bytes = new byte[buffers[i].capacity()];
                buffers[i].get(bytes);
                System.out.println("buf[" + i + "]: " + new String(bytes));
            }

            channel.close();
        }catch(FileNotFoundException ex){
            ex.printStackTrace();
        }catch(IOException ex){
            ex.printStackTrace();
        }
    }

    public static void main(String[] args){
        new ChannelTest4(args[0]);
    }
}