# Class AlgorithmParameterGeneratorSpi

java.lang.Object
java.security.AlgorithmParameterGeneratorSpi

public abstract class AlgorithmParameterGeneratorSpi extends Object
This class defines the Service Provider Interface (SPI) for the `AlgorithmParameterGenerator` class, which is used to generate a set of parameters to be used with a certain algorithm.

All the abstract methods in this class must be implemented by each cryptographic service provider who wishes to supply the implementation of a parameter generator for a particular algorithm.

In case the client does not explicitly initialize the AlgorithmParameterGenerator (via a call to an `engineInit` method), each provider must supply (and document) a default initialization. See the Keysize Restriction sections of the JDK Providers document for information on the AlgorithmParameterGenerator defaults used by JDK providers. However, note that defaults may vary across different providers. Additionally, the default value for a provider may change in a future version. Therefore, it is recommended to explicitly initialize the `AlgorithmParameterGenerator` instead of relying on provider-specific defaults.

Since:
  1.2
See Also:
  - `AlgorithmParameterGenerator`
  - `AlgorithmParameters`
  - `AlgorithmParameterSpec`

## Constructor Summary

Constructors
Constructor
Description
`AlgorithmParameterGeneratorSpi()`
Constructor for subclasses to call.

## Method Summary

Modifier and Type
Method
Description
`protected abstract AlgorithmParameters`
`engineGenerateParameters()`
Generates the parameters.
`protected abstract void`
`engineInit(int size, SecureRandom random)`
Initializes this parameter generator for a certain size and source of randomness.
`protected abstract void`
`engineInit(AlgorithmParameterSpec genParamSpec, SecureRandom random)`
Initializes this parameter generator with a set of algorithm-specific parameter generation values.

### Methods declared in class Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

## Constructor Details

### AlgorithmParameterGeneratorSpi

public AlgorithmParameterGeneratorSpi()
Constructor for subclasses to call.

## Method Details

### engineInit

protected abstract void engineInit(int size, SecureRandom random)
Initializes this parameter generator for a certain size and source of randomness.

Parameters:
  `size` - the size (number of bits).
  `random` - the source of randomness.

### engineInit

protected abstract void engineInit(AlgorithmParameterSpec genParamSpec, SecureRandom random) throws InvalidAlgorithmParameterException
Initializes this parameter generator with a set of algorithm-specific parameter generation values.

Parameters:
  `genParamSpec` - the set of algorithm-specific parameter generation values.
  `random` - the source of randomness.
Throws:
  `InvalidAlgorithmParameterException` - if the given parameter generation values are inappropriate for this parameter generator.

### engineGenerateParameters

protected abstract AlgorithmParameters engineGenerateParameters()
Generates the parameters.

Returns:
  the new `AlgorithmParameters` object.