FileTransfer.java

import java.io.*;
import java.math.BigInteger;


public class FileTransfer {
	public String DoubleToBinary(String file) throws IOException{
		FileReader in = new FileReader(file);
	 BufferedReader br = new BufferedReader(in);
	 String out = file + "_Binary";
	 File output = new File(out);
	 if (!output.exists()) {
	 	output.createNewFile();
		}
	 FileWriter fw = new FileWriter(output.getAbsoluteFile());
		BufferedWriter bw = new BufferedWriter(fw);
	 String line;
	 while((line = br.readLine()) != null){
	 	double d = Double.valueOf(line);
	 	String text = Long.toBinaryString(Double.doubleToRawLongBits(d));
	 	bw.write(text);
	 }
	 in.close();
	 bw.close();
		return out;		
	}
	
	// index of the number in raw file, start from 0
	public String BinaryToDouble(String file, int startIndex, int endIndex) throws IOException{
		FileReader in = new FileReader(file);
	 BufferedReader br = new BufferedReader(in);
	 String out = file + "_Normal";
	 File output = new File(out);
	 if (!output.exists()) {
	 	output.createNewFile();
		}
	 FileWriter fw = new FileWriter(output.getAbsoluteFile());
		BufferedWriter bw = new BufferedWriter(fw);
	 int c;
	 int counter_bit = 0;
	 int counter_num = 0;
	 StringBuilder line = new StringBuilder();
	 while ((c = br.read()) != -1) {
	 	if (counter_bit < startIndex * 62) {
	 		counter_bit++;
	 		continue;
	 	} else if (counter_bit >= (endIndex + 1) * 62) {
	 		break;
	 	} 
	 	if(counter_num == 0) line = new StringBuilder(); 	
	 	line.append( (char)c );
	 	if(counter_num == 61){
	 		String result = line.toString();
	 		double d = Double.longBitsToDouble(new BigInteger(result, 2).longValue());
		 	bw.write(Double.toString(d) + '\n');
	 		counter_num = -1;
	 	}
	 	counter_num ++;
	 	counter_bit ++;
	 }
	 in.close();
	 bw.close();
	 return out;
	}
	
	
	public static void main(String[] args) throws IOException{
// double d = 1.0;
// String text = Long.toBinaryString(Double.doubleToRawLongBits(d));
// System.out.println(text.length());
// System.out.println("0b "+ text);
// double nd = Double.longBitsToDouble(new BigInteger(text, 2).longValue());
// System.out.println("double "+nd);
		int startIndex = 3;
		int endIndex = 5;
		 FileTransfer s = new FileTransfer();
 String input = "svd.test.data.txt";
 String binaryFile = s.DoubleToBinary(input);
 String normalFile = s.BinaryToDouble(binaryFile, startIndex, endIndex);
// System.out.println(Double.doubleToRawLongBits(d));
 }
}