AlgorithmParameterGenerator getInstance() method in Java with Examples️‍🔥

Q: What is AlgorithmParameterGenerator getInstance() method in Java with Examples?

In this article, we will learn AlgorithmParameterGenerator getInstance() method in Java with Examples,This free JAVA tutorial for complete beginners will help you learn JAVA from scratch.

Q: How to use AlgorithmParameterGenerator getInstance() method in Java with Examples in JAVA?

The getInstance() method of java

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:

Java

// 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 using 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);
        }
    }
}

Output:

Status: java.security.AlgorithmParameterGenerator@232204a1

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 {
            // Getting instance of
            // AlgorithmParameterGenerator
            // By using 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);
        }
    }
}

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 the 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 {
            // Getting instance of
            // AlgorithmParameterGenerator
            // By using getInstance() method
            AlgorithmParameterGenerator sr
                = AlgorithmParameterGenerator
                      .getInstance("DSA");
 
            // creating Provider object
            Provider pd = sr.getProvider();
 
            // getting algorithm name
            // by using getAlgorithm() method
            String algo = sr.getAlgorithm();
 
            // Getting instance of
            // AlgorithmParameterGenerator
            // By using 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);
        }
    }
}

Output:

Status: java.security.AlgorithmParameterGenerator@232204a1

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 {
            // Getting instance of
            // AlgorithmParameterGenerator
            // By using getInstance() method
            AlgorithmParameterGenerator sr
                = AlgorithmParameterGenerator
                      .getInstance("GFG");
 
            // creating Provider object
            Provider pd = sr.getProvider();
 
            // getting algorithm name
            // by using getAlgorithm() method
            String algo = sr.getAlgorithm();
 
            // Getting instance of
            // AlgorithmParameterGenerator
            // By using 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);
        }
    }
}

Output:

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

Reference:

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