Java Program to Convert Byte Array to Hexadecimal

Last Updated : 28 Jan, 2021

In the problem given a byte array and the task is to convert the Byte Array to Hexadecimal value. A Java Byte Array is used to store byte data types only and the default value of each element is 0.

Example :

Input : byteArray = { 9, 2, 14, 10 }
Output: 09020E0A

Input : byteArray = { 7, 12, 13, 8 }
Output: 070C0D08

Approach:

Iterate through each byte in the array and convert it to a hexadecimal value.
The string.format() is used to print the number of places of a hexadecimal value and store it in a string.
%02X is used to print two places of a hexadecimal (X).

Below is the implementation of the above approach :

Java

// Java Program to convert byte
// array to hexadecimal value
import java.io.*;
  
class GFG {
    public static void
        convertByteToHexadecimal(byte[] byteArray)
    {
        // Iterating through each byte in the array
        for (byte i : byteArray) {
            String hex = String.format("%02X", i);
            System.out.print(hex);
        }
    }
    public static void main(String[] args)
    {
        byte[] byteArray = { 9, 2, 14, 10 };
        convertByteToHexadecimal(byteArray);
    }
}

Output

09020E0A

Efficient Approach:

In the above approach if the byte array gets larger, then the process becomes slow so to increase the efficiency a byte operation is used to convert the byte array to a hexadecimal value.

Here “>>>” is the unsigned right shift operator. And, toCharArray() method converts the given string into a sequence of characters.

Below is the implementation of the above approach :

Java

// Java program to convert byte array to
// hexadecimal array using byte operation
import java.io.*;
  
class GFG {
    public static void
        convertByteToHexadecimal(byte[] byteArray)
    {
        int len = byteArray.length;
  
        // storing the hexadecimal values
        char[] hexValues = "0123456789ABCDEF".toCharArray();
        char[] hexCharacter = new char[len * 2];
  
        // using  byte operation converting byte
        // array to hexadecimal value
        for (int i = 0; i < len; i++) {
            int v = byteArray[i] & 0xFF;
            hexCharacter[i * 2] = hexValues[v >>> 4];
            hexCharacter[i * 2 + 1] = hexValues[v & 0x0F];
        }
        System.out.println(hexCharacter);
    }
    public static void main(String[] args)
    {
        byte[] bytes = { 9, 2, 14, 10 };
        convertByteToHexadecimal(bytes);
    }
}

Output

09020E0A

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