public class AlgorithmParameterGenerator extends Object
AlgorithmParameterGenerator
class is used to generate a
set of
parameters to be used with a certain algorithm. Parameter generators
are constructed using the getInstance
factory methods
(static methods that return instances of a given class).
The object that will generate the parameters can be initialized in two different ways: in an algorithm-independent manner, or in an algorithm-specific manner:
In case the client does not explicitly initialize the
AlgorithmParameterGenerator
(via a call to an init
method), each provider must supply (and
document) a default initialization. For example, the Sun provider uses a
default modulus prime size of 1024 bits for the generation of DSA
parameters.
Every implementation of the Java platform is required to support the
following standard AlgorithmParameterGenerator
algorithms and
keysizes in parentheses:
DiffieHellman
(1024, 2048)DSA
(1024, 2048)AlgorithmParameters
,
AlgorithmParameterSpec
Modifier | Constructor | Description |
---|---|---|
protected |
AlgorithmParameterGenerator(AlgorithmParameterGeneratorSpi paramGenSpi,
Provider provider,
String algorithm) |
Creates an AlgorithmParameterGenerator object.
|
Modifier and Type | Method | Description |
---|---|---|
AlgorithmParameters |
generateParameters() |
Generates the parameters.
|
String |
getAlgorithm() |
Returns the standard name of the algorithm this parameter
generator is associated with.
|
static AlgorithmParameterGenerator |
getInstance(String algorithm) |
Returns an AlgorithmParameterGenerator object for generating
a set of parameters to be used with the specified algorithm.
|
static AlgorithmParameterGenerator |
getInstance(String algorithm,
String provider) |
Returns an AlgorithmParameterGenerator object for generating
a set of parameters to be used with the specified algorithm.
|
static AlgorithmParameterGenerator |
getInstance(String algorithm,
Provider provider) |
Returns an AlgorithmParameterGenerator object for generating
a set of parameters to be used with the specified algorithm.
|
Provider |
getProvider() |
Returns the provider of this algorithm parameter generator object.
|
void |
init(int size) |
Initializes this parameter generator for a certain size.
|
void |
init(int size,
SecureRandom random) |
Initializes this parameter generator for a certain size and source
of randomness.
|
void |
init(AlgorithmParameterSpec genParamSpec) |
Initializes this parameter generator with a set of algorithm-specific
parameter generation values.
|
void |
init(AlgorithmParameterSpec genParamSpec,
SecureRandom random) |
Initializes this parameter generator with a set of algorithm-specific
parameter generation values.
|
protected AlgorithmParameterGenerator(AlgorithmParameterGeneratorSpi paramGenSpi, Provider provider, String algorithm)
paramGenSpi
- the delegateprovider
- the provideralgorithm
- the algorithmpublic final String getAlgorithm()
public static AlgorithmParameterGenerator getInstance(String algorithm) throws NoSuchAlgorithmException
This method traverses the list of registered security Providers, starting with the most preferred Provider. A new AlgorithmParameterGenerator object encapsulating the AlgorithmParameterGeneratorSpi implementation from the first Provider that supports the specified algorithm is returned.
Note that the list of registered providers may be retrieved via
the Security.getProviders()
method.
jdk.security.provider.preferred
Security
property to determine
the preferred provider order for the specified algorithm. This
may be different than the order of providers returned by
Security.getProviders()
.algorithm
- the name of the algorithm this
parameter generator is associated with.
See the AlgorithmParameterGenerator section in the
Java Cryptography Architecture Standard Algorithm Name Documentation
for information about standard algorithm names.AlgorithmParameterGenerator
objectNoSuchAlgorithmException
- if no Provider
supports an
AlgorithmParameterGeneratorSpi
implementation for the
specified algorithmNullPointerException
- if algorithm
is null
Provider
public static AlgorithmParameterGenerator getInstance(String algorithm, String provider) throws NoSuchAlgorithmException, NoSuchProviderException
A new AlgorithmParameterGenerator object encapsulating the AlgorithmParameterGeneratorSpi implementation from the specified provider is returned. The specified provider must be registered in the security provider list.
Note that the list of registered providers may be retrieved via
the Security.getProviders()
method.
algorithm
- the name of the algorithm this
parameter generator is associated with.
See the AlgorithmParameterGenerator section in the
Java Cryptography Architecture Standard Algorithm Name Documentation
for information about standard algorithm names.provider
- the string name of the Provider.AlgorithmParameterGenerator
objectIllegalArgumentException
- if the provider name is null
or emptyNoSuchAlgorithmException
- if an
AlgorithmParameterGeneratorSpi
implementation for the specified algorithm is not
available from the specified providerNoSuchProviderException
- if the specified provider is not
registered in the security provider listNullPointerException
- if algorithm
is null
Provider
public static AlgorithmParameterGenerator getInstance(String algorithm, Provider provider) throws NoSuchAlgorithmException
A new AlgorithmParameterGenerator object encapsulating the AlgorithmParameterGeneratorSpi implementation from the specified Provider object is returned. Note that the specified Provider object does not have to be registered in the provider list.
algorithm
- the string name of the algorithm this
parameter generator is associated with.
See the AlgorithmParameterGenerator section in the
Java Cryptography Architecture Standard Algorithm Name Documentation
for information about standard algorithm names.provider
- the Provider
object.AlgorithmParameterGenerator
objectIllegalArgumentException
- if the specified provider is
null
NoSuchAlgorithmException
- if an
AlgorithmParameterGeneratorSpi
implementation for the specified algorithm is not available
from the specified Provider
objectNullPointerException
- if algorithm
is null
Provider
public final Provider getProvider()
public final void init(int size)
SecureRandom
implementation of the highest-priority installed provider is used as
the source of randomness.
(If none of the installed providers supply an implementation of
SecureRandom
, a system-provided source of randomness is
used.)size
- the size (number of bits).public final void init(int size, SecureRandom random)
size
- the size (number of bits).random
- the source of randomness.public final void init(AlgorithmParameterSpec genParamSpec) throws InvalidAlgorithmParameterException
SecureRandom
implementation of the highest-priority installed provider is used as
the source of randomness.
(If none of the installed providers supply an implementation of
SecureRandom
, a system-provided source of randomness is
used.)genParamSpec
- the set of algorithm-specific parameter generation values.InvalidAlgorithmParameterException
- if the given parameter
generation values are inappropriate for this parameter generator.public final void init(AlgorithmParameterSpec genParamSpec, SecureRandom random) throws InvalidAlgorithmParameterException
genParamSpec
- the set of algorithm-specific parameter generation values.random
- the source of randomness.InvalidAlgorithmParameterException
- if the given parameter
generation values are inappropriate for this parameter generator.public final AlgorithmParameters generateParameters()
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For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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DRAFT 9-internal+0-adhoc.mlchung.jdk9-jdeps