How to Hash Strings with SHA-256 in Java?

How to Utilize the SHA-256 Algorithm for String Hashing in Java

Hashing plays a crucial role in safeguarding, validating, and tracking data. The SHA-256 algorithm is widely used for its efficiency and security in producing a secure representation of input data. In Java, hashing strings using SHA-256 is straightforward.

Hashing Strings with SHA-256

Despite popular terminology, SHA-256 does not "encode" data; rather, it generates a one-way hash. The process involves converting the input string into an array of bytes and then applying the SHA-256 algorithm. It's important to note that the output of the hashing process is binary data, not a string.

To represent the resulting binary data as a string for further processing or transmission, consider using Base64 or hexadecimal encoding. Avoid using the String(byte[], String) constructor for this purpose.

Example Code

Below is an example code snippet that demonstrates how to hash a string using the SHA-256 algorithm in Java:

<code class="java">import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;

public class StringHashingWithSHA256 {

    public static void main(String[] args) throws NoSuchAlgorithmException {

        // Obtain a SHA-256 message digest instance
        MessageDigest digest = MessageDigest.getInstance("SHA-256");

        // Convert the input string into bytes using UTF-8
        byte[] inputBytes = "Your Input String".getBytes(StandardCharsets.UTF_8);

        // Perform SHA-256 hashing on the input bytes
        byte[] hashedBytes = digest.digest(inputBytes);

        // Display the hashed bytes (in lowercase hexadecimal format)
        System.out.println(Arrays.toString(hashedBytes).toLowerCase());
    }
}</code>

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