How to Hash a String with SHA-256 in Java?

Hashing a String with SHA-256 in Java

Despite the common misconception as an "encoding," SHA-256 operates as a one-way hash function. To effectively hash a String using SHA-256 in Java, you must follow these steps:

1. Convert the String into bytes using a character encoding such as StandardCharsets.UTF_8.
2. Create a MessageDigest instance using the SHA-256 algorithm.
3. Compute the hash by passing the byte array to the digest object.

Code Example:

<code class="java">import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;

class Sha256Hash {

    public static void main(String[] args) throws Exception {
        String text = "Some String";

        // Convert to bytes
        byte[] bytes = text.getBytes(StandardCharsets.UTF_8);

        // Create SHA-256 digest
        MessageDigest digest = MessageDigest.getInstance("SHA-256");

        // Compute the hash
        byte[] hash = digest.digest(bytes);

        // Print the hash (in hexadecimal representation)
        System.out.println(toHexString(hash));
    }

    private static String toHexString(byte[] bytes) {
        StringBuilder sb = new StringBuilder();
        for (byte b : bytes) {
            sb.append(String.format("%02x", b));
        }
        return sb.toString();
    }
}</code>

The above is the detailed content of How to Hash a String with SHA-256 in Java?. For more information, please follow other related articles on the PHP Chinese website!