AlgorithmParameterGenerator getInstance() method in Java with Examples

getInstance(String algorithm)

The getInstance() method of java.security.AlgorithmParameterGenerator class is used to return an object of AlgorithmParameterGenerator type that implements the specified algorithm.

Syntax:

public static AlgorithmParameterGenerator 
  getInstance(String algorithm)
    throws NoSuchAlgorithmException

Parameters: This method takes the standard name of Algorithm as a parameter.



Return Value: This method returns the new AlgorithmParameterGenerator object.

Exception: This method throws following exception:

  • NoSuchAlgorithmException: if no Provider supports an AlgorithmParameterGeneratorSpi implementation for the specified algorithm.
  • NullPointerException: if the specified algorithm is null.

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

Example 1:

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

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Output:

Status: java.security.AlgorithmParameterGenerator@232204a1

Example 2: To show NoSuchAlgorithmException

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

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Output:

Exception thrown:
 java.security.NoSuchAlgorithmException:
 GFG AlgorithmParameterGenerator not available

Signature getInstance(String algorithm, Provider provider)

The getInstance() method of java.security.AlgorithmParameterGenerator class is used to return a AlgorithmParameterGenerator object that implements the specified signature algorithm and specified provider object.

Syntax:

public static AlgorithmParameterGenerator
  getInstance(String algorithm, Provider provider)
    throws NoSuchAlgorithmException

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


  • algorithm: which is the name of the algorithm requested.
  • provider: which is the provider specified

Return Value: This method returns the new AlgorithmParameterGenerator object.

Exception: This method throws following exceptions:

  • NoSuchAlgorithmException: if a AlgorithmParameterGeneratorSpi implementation for the specified algorithm is not available from the specified Provider object.
  • IllegalArgumentException: if the provider is null.
  • NullPointerException: if algorithm is null

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

Example 1:

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// Java program to demonstrate
// getInstance() method
  
import java.security.*;
import java.util.*;
  
public class GFG1 {
    public static void main(String[] argv)
    {
        try {
            // Getting instance of
            // AlgorithmParameterGenerator
            // By usng getInstance() method
            AlgorithmParameterGenerator sr
                = AlgorithmParameterGenerator
                      .getInstance("DSA");
  
            // creating Provider object
            Provider pd = sr.getProvider();
  
            // getting algorithm name
            // by using getAlgorithm() mathod
            String algo = sr.getAlgorithm();
  
            // Getting instance of
            // AlgorithmParameterGenerator
            // By usng getInstance() method
            AlgorithmParameterGenerator sr1
                = AlgorithmParameterGenerator
                      .getInstance(algo, pd);
  
            // getting the status of
            // AlgorithmParameterGenerator object
            String str = sr1.toString();
  
            // printing the status
            System.out.println("Status: "
                               + str);
        }
  
        catch (NoSuchAlgorithmException e) {
  
            System.out.println("Exception thrown: "
                               + e);
        }
        catch (IllegalArgumentException e) {
  
            System.out.println("Exception thrown: "
                               + e);
        }
    }
}

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Output:

Status: java.security.AlgorithmParameterGenerator@232204a1

Example 2: To show NoSuchAlgorithmException

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// Java program to demonstrate
// getInstance() method
  
import java.security.*;
import java.util.*;
  
public class GFG1 {
    public static void main(String[] argv)
    {
        try {
            // Getting instance of
            // AlgorithmParameterGenerator
            // By usng getInstance() method
            AlgorithmParameterGenerator sr
                = AlgorithmParameterGenerator
                      .getInstance("GFG");
  
            // creating Provider object
            Provider pd = sr.getProvider();
  
            // getting algorithm name
            // by using getAlgorithm() mathod
            String algo = sr.getAlgorithm();
  
            // Getting instance of
            // AlgorithmParameterGenerator
            // By usng getInstance() method
            AlgorithmParameterGenerator sr1
                = AlgorithmParameterGenerator
                      .getInstance(algo, pd);
  
            // getting the status of
            // AlgorithmParameterGenerator object
            String str = sr1.toString();
  
            // printing the status
            System.out.println("Status: " + str);
        }
  
        catch (NoSuchAlgorithmException e) {
  
            System.out.println("Exception thrown: "
                               + e);
        }
        catch (IllegalArgumentException e) {
  
            System.out.println("Exception thrown: "
                               + e);
        }
    }
}

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Output:

Exception thrown:
 java.security.NoSuchAlgorithmException:
 GFG AlgorithmParameterGenerator not available

Reference:



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