将数组字节转换为二进制

Question

please any one can help me to convert the ascciiText to binary such as 49 have binary 00110001 and 48 is 00110010 and so on this is my code

import java.lang.String;
import java.util.Scanner;
import java.lang.*;
import java.io.*;
import java.util.*;

public class encrption {

public static void main(String[] args){

     // INPUT: KeyText   (StrKey).
    // OUTPUT: Ciphertext (ConcatenatedData).
   //String ConcatenatedData; 


    // Read data from user.
    Scanner in = new Scanner(System.in);
    System.out.println("Enter Your PlainText");
    String StrValue = in.nextLine();
    System.out.println("Enter Your KeyText ");
    String StrKey = in.nextLine();

  // Print the Concatenated Data.

 String ConcatenatedData = StrKey.concat(StrValue);
       System.out.println("the Concatenated Data is :"+ConcatenatedData);

  // Convering the Concatenated data to Ascii data.

 try { 
  byte[] asciiText = ConcatenatedData.getBytes("US-ASCII");


    System.out.println(Arrays.toString(asciiText)); 

}

 catch (java.io.UnsupportedEncodingException e)
     { e.printStackTrace(); }

Please any one can help me to convert the series of ascciiText to binary such as 49 have binary 00110001 and 48 is 00110010 and so on

Configuration: encrption - JDK version 1.8.0_40

Enter Your PlainText welcome Enter Your KeyText 123 the Concatenated Data is :123welcome [49, 50, 51, 119, 101, 108, 99, 111, 109, 101]

Process completed.

Answer 1

Since byte doesn't provide any method for this you'll have to use Integer :

byte[] b = ...;//you're array
String binStr = "";

for(byte v : b)
    binStr += Integer.toBinaryString(v);

Or you could write your own method. Wouldn't be too difficult aswell:

String toBinary(byte b){
    char[] binArr = new char[8];

    //if a bit is 1, emplace '1' at the respective position in the array, else 0
    for(int i = 0 ; i < 8 ; i++)
        binArr[7 - i] = (b & (1 << i)) == 0 ? '0' : '1';

    return new String(binArr);
}

Answer 2

Simialr on @Paul's solution but written another way.

String toBinary(byte b) {
    StringBuilder sb = new StringBuilder(8);

    for(int i = 7 ; i >= 0 ; i--)
        sb.append((char) ('0' + ((b >> i) & 1));

    return sb.toString();
}