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 NoSuchAlgorithmExceptionParameters: 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() methodimport 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() methodimport 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 NoSuchAlgorithmExceptionParameters: 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() methodimport 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() methodimport 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-