The reset() method of java.security.MessageDigest class is used to reset current message digest value to default message digest value of this MessageDisgest object.
Syntax:
public void reset()
Return Value: This method has nothing to return.
Below are the examples to illustrate the reset() method:
Example 1:
Java
// Java program to demonstrate// reset() methodimport java.security.*;import java.nio.*;import java.util.*;public class GFG1 { public static void main(String[] argv) { try { byte[] barr = { 10, 20, 30, 40 }; // creating object of MessageDigest MessageDigest msd1 = MessageDigest.getInstance("MD5"); // display the digest value before Updation System.out.println("MessageDigest before update : " + (ByteBuffer.wrap( msd1.digest())) .getShort()); // creating object of ByteBuffer // and allocating size capacity ByteBuffer bb = ByteBuffer.wrap(barr); // update MessageDigest value // using update() method msd1.update(bb); // display the digest value before Updation System.out.println("\nMessageDigest after update : " + (ByteBuffer.wrap( msd1.digest())) .getShort()); // reset MessageDigest value // using reset() method msd1.reset(); // display the digest value after reset System.out.println("\nMessageDigest after reset : " + (ByteBuffer.wrap( msd1.digest())) .getShort()); } catch (NoSuchAlgorithmException e) { System.out.println("Exception thrown : " + e); } catch (ProviderException e) { System.out.println("Exception thrown : " + e); } }} |
Output:
MessageDigest before update : -11235 MessageDigest after update : 30835 MessageDigest after reset : -11235
Example 2:
Java
// Java program to demonstrate// reset() methodimport java.security.*;import java.nio.*;import java.util.*;public class GFG1 { public static void main(String[] argv) { try { byte[] barr = { 10, 20, 30, 40 }; // creating object of MessageDigest MessageDigest msd1 = MessageDigest.getInstance("SHA-256"); // display the digest value before Updation System.out.println("MessageDigest before update : " + (ByteBuffer.wrap( msd1.digest())) .getShort()); // creating object of ByteBuffer // and allocating size capacity ByteBuffer bb = ByteBuffer.wrap(barr); // update MessageDigest value // using update() method msd1.update(bb); // display the digest value before Updation System.out.println("\nMessageDigest after update : " + (ByteBuffer.wrap( msd1.digest())) .getShort()); // reset MessageDigest value // using reset() method msd1.reset(); // display the digest value after reset System.out.println("\nMessageDigest after reset : " + (ByteBuffer.wrap( msd1.digest())) .getShort()); } catch (NoSuchAlgorithmException e) { System.out.println("Exception thrown : " + e); } catch (ProviderException e) { System.out.println("Exception thrown : " + e); } }} |
Output:
MessageDigest before update : -7248 MessageDigest after update : 24403 MessageDigest after reset : -7248
Reference:
https://docs.oracle.com/javase/9/docs/api/java/security/MessageDigest.html#reset–