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 applies 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:
Java
// 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); } } } |
algorithm : DSA
Example 2: To show NoSuchAlgorithmException
Java
// 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("Beginner"); // 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); } } } |
Exception thrown : java.security.NoSuchAlgorithmException: Beginner KeyFactory not available
getInstance(String algorithm, String provider)
The getInstance() method of java.security.KeyFactory class returns a object of KeyFactory type that applies 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:
Java
// 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); } } } |
algorithm : DSA
Example 2: To show NoSuchAlgorithmException
Java
// 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); } } } |
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-