Program to convert byte array data to hexadecimal

Program to convert byte array data to hexadecimal

public class ByteArrayDemo

{

             protected static final byte[] Hexhars =

            {

                        '0', '1', '2', '3', '4', '5',

                        '6', '7', '8', '9', 'a', 'b',

                        'c', 'd', 'e', 'f'

            };

           

            public String byteArrayToHexString(byte[] b)

            {

//Constructs a string builder with no characters in it and an initial capacity specified by the capacity argument.

                        StringBuilder s = new StringBuilder(2 * b.length);

                     

                        for (int i = 0; i < b.length; i ++)

                        {

                                    int v = b[i] & 0xff;

                                    /*

                                     * ANDs b[i] with 0xFF

 * The value of b[i] is 65(Whose binary is 01000001), we AND it with 0xFF(whose Binary is 11111111)

                                     * resulting in the binary 01000001

                                     */

                                    s.append((char) Hexhars[v >> 4]);

                                    /*

                                     * v >> 4 - Right shifts the value of v(01000001) to 4 places

                                     * On 1st right shift, we get 00100000

                                    * On 2nd right shift, we get 00010000

                                    * On 3rd right shift, we get 00001000

                                    * On 4th right shift, we get 00000100

                                    * Which is 4

* Hexhars[4] - Finds the value at the 4th place(starting from 0) from the byte array Hexhars

                                    */

                                   

s.append((char) Hexhars[v & 0xf]);

                                    /*

                                     * ANDs b[i] with 0xF

* The value of b[i] is 65(Whose binary is 01000001), we AND it with 0xF(whose Binary is 00001111)

                                    * resulting in the binary 00000001 - 1

                                    * Hexhars[1] - Finds the value at the 1st place from the byte array Hexhars

                                    */

}

                        return s.toString();

            }

           

         

            public static void main(String[] args)

            {

                        byte[] byteArray = new byte[] {65};

                        ByteArrayDemo obyteArrayDemo = new ByteArrayDemo();

                        String sData = obyteArrayDemo.byteArrayToHexString(byteArray);                        

                        System.out.println(sData);                          

            }

}