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–
