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

public class ChannelTest2 {
    private String[] texts = {"ABCDEFGHIJKLMNOPQRSTUVWXYZ",
                              "abcdefghijklmnopqrstuvwxyz",
                              "0123456789",
                              "あいうえお"};

    public ChannelTest2(String filename) {
        write(filename);
        read(filename);
    }

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

                channel.write(buffer);
            }

            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();
        
            int sizeOfReadingBytes = 0;

            while (sizeOfReadingBytes < channel.size()){
                ByteBuffer buffer = ByteBuffer.allocate(10);
                buffer.clear();

                sizeOfReadingBytes += channel.read(buffer);
                
                buffer.clear();
                byte[] bytes = new byte[buffer.capacity()];
                buffer.get(bytes);
                System.out.println("Buffer: " + new String(bytes));
            }

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

    public static void main(String[] args){
        new ChannelTest2(args[0]);
    }
}