package readdoubleapp;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.PrintStream;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.channels.FileChannel;

public class ReadDoubleApp {
    final static String PATH = "D:/fil.dat";
    public static void main(String[] args) {
        PrintStream s = System.out;
        try {
            FileInputStream fis = new FileInputStream(PATH);
            FileChannel channel = fis.getChannel();

            ByteBuffer bb = ByteBuffer.allocate(64 * 1024);
//            bb.order(ByteOrder.BIG_ENDIAN); //по-умолчанию стоит BIG_ENDIAN
//            bb.order(ByteOrder.LITTLE_ENDIAN);
            bb.order(ByteOrder.nativeOrder()); //для моей платформы родной LITTLE_ENDIAN (у меня AMD), на Интеле - BIG_ENDIAN
            
            channel.read(bb);
            bb.flip();

            int cnt = 0;
            while (bb.remaining() >= 8) {
                s.print("Дабл [");
                s.print(++cnt);
                s.print("]: ");
                s.println(bb.getDouble());
            }
        } catch (IOException e) {
            s.println("IOException : " + e);
        }
    }
}

package readdoubleapp;

import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.PrintStream;

public class ReadDoubleApp {

    final static String PATH = "D:/fil.dat";

    public static void main(String[] args) {
        PrintStream s = System.out;
        try {
            FileInputStream fis = new FileInputStream(PATH);
            DataInputStream dis = new DataInputStream(fis);

            int cnt = 0;
            while (dis.available() >= 8) {
                s.print("Дабл [");
                s.print(++cnt);
                s.print("]: ");
                s.println(dis.readDouble());
            }
        } catch (IOException e) {
            s.println("IOException : " + e);
        }
    }
}