Write a java program to convert a byte array to string

We have to write a java program to convert byte array to string. For this, let us first understand what is byte and byte array in java.

What is a byte?

A byte is a numerical data type in java just like an integer data type. It requires a memory of 1 byte i.e. 8 bits. It can hold values from -128 to +127. Thus, for variables whose values fall in this range and require less memory, the byte data type is used.

Now, let us understand what is a byte array.

What is a byte array?

Just like we have an array of integers, we can have an array of bytes. This array of bytes is known as a byte array.

How to initialize a byte array?

To initialize a byte array, you need to know the no. of elements to be present in the array. The declaration for the same is as given below:

byte[] arr=new byte[10];

We can also obtain the byte array by converting a string into bytes using getBytes() method as shown below:

byte[] arr=”Desired String”.getBytes();

How to convert a byte array into a string?

The process of converting a byte array into a string is called decoding.

A byte array can be converted to string using any of the two methods:-

Using String Class Constructor -> String s=new String(bytearray);
Using UTF_8 Encoding -> String s=new String(bytearray, StandardCharSets.UTF_8);

Example:

Input:

Enter a string: Hello

Output:

The byte array is : [B@1f96302

The string obtained using the string class constructor is: Hello

The string obtained using UTF_8 encoding is: Hello

Write an algorithm to convert a byte array to string:

Take a string input from the user.
Next, obtain the byte array of string using getBytes() method.
You can also print the byte array.
To convert the byte array to string using string class constructor, create a string constructor with the byte array as argument. The desired string is obtained. Simply, print the string.
Or you can also use character encoding for the same. For this, create a string constructor with two arguments – byte array and character encoding using StandardCharSets.UTF_8. Again simply print the string obtained.

Write a program to convert a byte array to string:

import java.util.Scanner;
import java.nio.charset.StandardCharsets;

public class ByteToString 
{
    public static void main(String[] args) 
    {
        Scanner sc=new Scanner(System.in);
        System.out.println("Enter a string");
        String s=sc.next();
        byte[] arr=s.getBytes();
        System.out.println("The byte array is: "+arr);
        String s1=new String(arr);
        System.out.println("The string obtained using string class constructor is: "+s1);
        String s2=new String(arr, StandardCharsets.UTF_8);
        System.out.println("The string obtained using UTF_8 : "+s2);
    }
}