KeyFactory getInstance() method in Java with Examples

getInstance(String algorithm)

The getInstance() method of java.security.KeyFactory class returns a object of KeyFactory type that applys the assigned KeyFactory algorithm.

Syntax:

public static KeyFactory
  getInstance(String algorithm)
  throws NoSuchAlgorithmException

Parameters: This method seeks the standard Algorithm as a parameter whose instance is to be created to this KeyFactory instance.

Return Value: This method returns a new key factory object.

Exception: This method throws following exception:



  • NoSuchAlgorithmException: if no provider is available to support an key factory spi application for the particular algorithm.
  • NullPointerException: if algorithm is null.

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

Example 1:

filter_none

edit
close

play_arrow

link
brightness_4
code

// Java program to demonstrate
// getInstance() method
  
import java.security.*;
import java.util.*;
  
public class GFG1 {
    public static void main(String[] argv)
    {
  
        try {
  
            // creating the object of KeyFactory
            // and getting instance
            // By using getInstance() method
            KeyFactory sr
                = KeyFactory.getInstance("DSA");
  
            // getting the algorithm of KeyFactory object
            String str = sr.getAlgorithm();
  
            // printing the status
            System.out.println("algorithm : " + str);
        }
  
        catch (NoSuchAlgorithmException e) {
  
            System.out.println("Exception thrown : " + e);
        }
        catch (NullPointerException e) {
  
            System.out.println("Exception thrown : " + e);
        }
    }
}

chevron_right






                        filter_none









Output:


algorithm : DSA





Example 2: To show NoSuchAlgorithmException











                                    filter_none




                                    edit

                                    close




                                    play_arrow




                                    link

                                    brightness_4

                                    code
                                




















// Java program to demonstrate 


// getInstance() method 


  


import java.security.*; 


import java.util.*; 


  


public class GFG1 { 


    public static void main(String[] argv) 


    { 


  


        try { 


  


            // creating the object of KeyFactory 


            // and getting instance 


            // By using getInstance() method 


            KeyFactory sr = KeyFactory.getInstance("GEEKS"); 


  


            // getting the algorithm of KeyFactory object 


            String str = sr.getAlgorithm(); 


  


            // printing the status 


            System.out.println("algorithm : " + str); 


        } 


  


        catch (NoSuchAlgorithmException e) { 


  


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


        } 


        catch (NullPointerException e) { 


  


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


        } 


    } 


} 



















                        chevron_right







                        filter_none









Output:


Exception thrown :
 java.security.NoSuchAlgorithmException:
 GEEKS KeyFactory not available





 getInstance(String algorithm, String provider)


The getInstance() method of java.security.KeyFactory class returns a object of KeyFactory type that applys the assigned KeyFactory algorithm and assigned provider object.


Syntax:


public static KeyFactory
  getInstance(String algorithm, String provider)
  throws NoSuchAlgorithmException


Parameters: This method seeks the following arguments as a parameters:




    

  • algorithm: which is the name of the algorithm specified to get the instance.
    • 

  • provider: which is the name of the provider to be specified
    • 



Return Value: This method returns an new key factory object.


Exception: This method throws following exceptions:


    

  • NoSuchAlgorithmException:– if no provider is available to support an key factory spi application for the particular algorithm.
    • 

  • IllegalArgumentException:– if the provider is null.
    • 

  • NullPointerException:– if algorithm is null
    • 



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


Example 1:











                                    filter_none




                                    edit

                                    close




                                    play_arrow




                                    link

                                    brightness_4

                                    code
                                




















// Java program to demonstrate 


// getInstance() method 


  


import java.security.*; 


import java.util.*; 


  


public class GFG1 { 


    public static void main(String[] argv) 


    { 


        try { 


            // creating the object of KeyFactory 


            // and getting instance 


            // By using getInstance() method 


            KeyFactory sr 


                = KeyFactory.getInstance( 


                    "DSA", "SUN"); 


  


            // getting the algorithm of KeyFactory object 


            String str = sr.getAlgorithm(); 


  


            // printing the status 


            System.out.println("algorithm : " + str); 


        } 


  


        catch (NoSuchAlgorithmException e) { 


  


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


        } 


        catch (NullPointerException e) { 


  


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


        } 


        catch (NoSuchProviderException e) { 


  


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


        } 


    } 


} 



















                        chevron_right







                        filter_none









Output:


algorithm : DSA





Example 2: To show NoSuchAlgorithmException











                                    filter_none




                                    edit

                                    close




                                    play_arrow




                                    link

                                    brightness_4

                                    code
                                




















// Java program to demonstrate 


// getInstance() method 


  


import java.security.*; 


import java.util.*; 


  


public class GFG1 { 


    public static void main(String[] argv) 


    { 


        try { 


            // creating the object of KeyFactory 


            // and getting instance 


            // By using getInstance() method 


            KeyFactory sr 


                = KeyFactory.getInstance( 


                    "RSA", "SUN"); 


  


            // getting the algorithm of KeyFactory object 


            String str = sr.getAlgorithm(); 


  


            // printing the status 


            System.out.println("algorithm : " + str); 


        } 


  


        catch (NoSuchAlgorithmException e) { 


  


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


        } 


        catch (NullPointerException e) { 


  


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


        } 


        catch (NoSuchProviderException e) { 


  


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


        } 


    } 


} 



















                        chevron_right







                        filter_none









Output:


Exception thrown :
 java.security.NoSuchAlgorithmException:
 no such algorithm: RSA for provider SUN





Reference: https://docs.oracle.com/javase/9/docs/api/java/security/KeyFactory.html#getInstance-java.lang.String-


Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.





    

        My Personal Notes
        arrow_drop_up
    

    

        
        

            
            
        

    


Recommended Posts:
RohitPrasad3
Check out this Author's contributed articles.
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on  the "Improve Article" button below.


Improved By :  Akanksha_Rai