MessageDigest getDigestLength() method in Java with Examples

The getDigestLength() method of MessageDigest class is used to get the size of object of message digest object in bytes.

Syntax:

public final int getDigestLength()

Return Value: This method provides the length of the message digest in byte form.

Below are the examples to illustrate the getDigestLength() method:

Example 1:

// Java program to demonstrate
// getDigestLength() method

import java.security.*;
import java.util.*;

public class GFG1 {
    public static void main(String[] argv)
    {
        try {

            // creating object of MessageDigest
            MessageDigest msd
                = MessageDigest.getInstance("SHA-256", "SUN");

            // getting the length of MessageDigest of object msd
            // by using method getDigestLength()
            int length = msd.getDigestLength();

            // printing the provider name
            System.out.println("Message digest length : "
                               + length);
        }

        catch (NoSuchAlgorithmException e) {

            System.out.println("Exception thrown : " + e);
        }
        catch (NoSuchProviderException e) {

            System.out.println("Exception thrown : " + e);
        }
    }
}

Output:

Message digest length : 32

Example 2:

// Java program to demonstrate
// getDigestLength() method

import java.security.*;
import java.util.*;

public class GFG1 {
    public static void main(String[] argv)
    {
        try {

            // creating object of MessageDigest
            MessageDigest msd
                = MessageDigest.getInstance("MD5");

            // getting the length of MessageDigest of object msd
            // by using method getDigestLength()
            int length = msd.getDigestLength();

            // printing the provider name
            System.out.println("Message digest length : "
                               + length);
        }

        catch (NoSuchAlgorithmException e) {

            System.out.println("Exception thrown : " + e);
        }
    }
}

Output:

Message digest length : 16

Reference: https://docs.oracle.com/javase/9/docs/api/java/security/MessageDigest.html#getDigestLength–