Summary: Protected Ctors | Methods | Inherited Methods

AlgorithmParameters

public class AlgorithmParameters
extends Object

java.lang.Object
↳	java.security.AlgorithmParameters

This class is used as an opaque representation of cryptographic parameters.

An AlgorithmParameters object for managing the parameters for a particular algorithm can be obtained by calling one of the getInstance factory methods (static methods that return instances of a given class).

Once an AlgorithmParameters object is obtained, it must be initialized via a call to init, using an appropriate parameter specification or parameter encoding.

A transparent parameter specification is obtained from an AlgorithmParameters object via a call to getParameterSpec, and a byte encoding of the parameters is obtained via a call to getEncoded.

Android provides the following AlgorithmParameters algorithms:

Algorithm	Supported API Levels
AES	1+
BLOWFISH	10+
ChaCha20	28+
DES	1+
DESede	1+
DH	1+
DSA	1+
EC	26+
GCM	22+
IES	1-8
OAEP	1+
PBEwithHmacSHA1AndAES_128	26+
PBEwithHmacSHA1AndAES_256	26+
PBEwithHmacSHA224AndAES_128	26+
PBEwithHmacSHA224AndAES_256	26+
PBEwithHmacSHA256AndAES_128	26+
PBEwithHmacSHA256AndAES_256	26+
PBEwithHmacSHA384AndAES_128	26+
PBEwithHmacSHA384AndAES_256	26+
PBEwithHmacSHA512AndAES_128	26+
PBEwithHmacSHA512AndAES_256	26+
PKCS12PBE	1+
PSS	1-8,24+

See also:

Summary

Protected constructors
`AlgorithmParameters(AlgorithmParametersSpi paramSpi, Provider provider, String algorithm)` Creates an AlgorithmParameters object.

Public methods
`final String`	`getAlgorithm()` Returns the name of the algorithm associated with this parameter object.
`final byte[]`	`getEncoded(String format)` Returns the parameters encoded in the specified scheme.
`final byte[]`	`getEncoded()` Returns the parameters in their primary encoding format.
`static AlgorithmParameters`	`getInstance(String algorithm)` Returns a parameter object for the specified algorithm.
`static AlgorithmParameters`	`getInstance(String algorithm, String provider)` Returns a parameter object for the specified algorithm.
`static AlgorithmParameters`	`getInstance(String algorithm, Provider provider)` Returns a parameter object for the specified algorithm.
`final <T extends AlgorithmParameterSpec> T`	`getParameterSpec(Class<T> paramSpec)` Returns a (transparent) specification of this parameter object.
`final Provider`	`getProvider()` Returns the provider of this parameter object.
`final void`	`init(byte[] params)` Imports the specified parameters and decodes them according to the primary decoding format for parameters.
`final void`	`init(AlgorithmParameterSpec paramSpec)` Initializes this parameter object using the parameters specified in `paramSpec`.
`final void`	`init(byte[] params, String format)` Imports the parameters from `params` and decodes them according to the specified decoding scheme.
`final String`	`toString()` Returns a formatted string describing the parameters.

Inherited methods

From class java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Protected constructors

AlgorithmParameters

Added in API level 1

 protected AlgorithmParameters (AlgorithmParametersSpi paramSpi, Provider provider, String algorithm)

Creates an AlgorithmParameters object.

Parameters
`paramSpi`	`AlgorithmParametersSpi`: the delegate
`provider`	`Provider`: the provider
`algorithm`	`String`: the algorithm

Public methods

getAlgorithm

Added in API level 1

 public final String getAlgorithm ()

Returns the name of the algorithm associated with this parameter object.

Returns
`String`	the algorithm name.

getEncoded

Added in API level 1

 public final byte[] getEncoded (String format)

Returns the parameters encoded in the specified scheme. If format is null, the primary encoding format for parameters is used. The primary encoding format is ASN.1, if an ASN.1 specification for these parameters exists.

Parameters
`format`	`String`: the name of the encoding format.

Returns
`byte[]`	the parameters encoded using the specified encoding scheme.

Throws
`IOException`	on encoding errors, or if this parameter object has not been initialized.

getEncoded

Added in API level 1

 public final byte[] getEncoded ()

Returns the parameters in their primary encoding format. The primary encoding format for parameters is ASN.1, if an ASN.1 specification for this type of parameters exists.

Returns
`byte[]`	the parameters encoded using their primary encoding format.

Throws
`IOException`	on encoding errors, or if this parameter object has not been initialized.

getInstance

Added in API level 1

 public static AlgorithmParameters getInstance (String algorithm)

Returns a parameter object for the specified algorithm.

This method traverses the list of registered security Providers, starting with the most preferred Provider. A new AlgorithmParameters object encapsulating the AlgorithmParametersSpi 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.

The returned parameter object must be initialized via a call to init, using an appropriate parameter specification or parameter encoding.

Parameters
`algorithm`	`String`: the name of the algorithm requested.

Returns
`AlgorithmParameters`	the new parameter object

Throws
`NoSuchAlgorithmException`	if no `Provider` supports an `AlgorithmParametersSpi` implementation for the specified algorithm
`NullPointerException`	if `algorithm` is `null` on Android 14 or above

See also:

Provider

getInstance

Added in API level 1

 public static AlgorithmParameters getInstance (String algorithm, String provider)

Returns a parameter object for the specified algorithm.

A new AlgorithmParameters object encapsulating the AlgorithmParametersSpi 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.

The returned parameter object must be initialized via a call to init, using an appropriate parameter specification or parameter encoding.

Parameters
`algorithm`	`String`: the name of the algorithm requested.
`provider`	`String`: the name of the provider.

Returns
`AlgorithmParameters`	the new parameter object

Throws
`IllegalArgumentException`	if the provider name is `null` or empty
`NoSuchAlgorithmException`	if an `AlgorithmParametersSpi` implementation for the specified algorithm is not available from the specified provider
`NoSuchProviderException`	if the specified provider is not registered in the security provider list
`NullPointerException`	if `algorithm` is `null` on Android 14 or above

See also:

Provider

getInstance

Added in API level 1

 public static AlgorithmParameters getInstance (String algorithm, Provider provider)

Returns a parameter object for the specified algorithm.

A new AlgorithmParameters object encapsulating the AlgorithmParametersSpi implementation from the specified Provider object is returned. Note that the specified Provider object does not have to be registered in the provider list.

The returned parameter object must be initialized via a call to init, using an appropriate parameter specification or parameter encoding.

Parameters
`algorithm`	`String`: the name of the algorithm requested.
`provider`	`Provider`: the name of the provider.

Returns
`AlgorithmParameters`	the new parameter object

Throws
`IllegalArgumentException`	if the provider is `null`
`NoSuchAlgorithmException`	if an `AlgorithmParameterGeneratorSpi` implementation for the specified algorithm is not available from the specified `Provider` object
`NullPointerException`	if `algorithm` is `null` on Android 14 or above

See also:

Provider

getParameterSpec

Added in API level 1

 public final T getParameterSpec (Class<T> paramSpec)

Returns a (transparent) specification of this parameter object. paramSpec identifies the specification class in which the parameters should be returned. It could, for example, be DSAParameterSpec.class, to indicate that the parameters should be returned in an instance of the DSAParameterSpec class.

Parameters
`paramSpec`	`Class`: the specification class in which the parameters should be returned.

Returns
`T`	the parameter specification.

Throws
`InvalidParameterSpecException`	if the requested parameter specification is inappropriate for this parameter object, or if this parameter object has not been initialized.

getProvider

Added in API level 1

 public final Provider getProvider ()

Returns the provider of this parameter object.

Returns
`Provider`	the provider of this parameter object

init

Added in API level 1

 public final void init (byte[] params)

Imports the specified parameters and decodes them according to the primary decoding format for parameters. The primary decoding format for parameters is ASN.1, if an ASN.1 specification for this type of parameters exists.

Parameters
`params`	`byte`: the encoded parameters.

Throws
`IOException`	on decoding errors, or if this parameter object has already been initialized.

init

Added in API level 1

 public final void init (AlgorithmParameterSpec paramSpec)

Initializes this parameter object using the parameters specified in paramSpec.

Parameters
`paramSpec`	`AlgorithmParameterSpec`: the parameter specification.

Throws
`InvalidParameterSpecException`	if the given parameter specification is inappropriate for the initialization of this parameter object, or if this parameter object has already been initialized.

init

Added in API level 1

 public final void init (byte[] params, String format)

Imports the parameters from params and decodes them according to the specified decoding scheme. If format is null, the primary decoding format for parameters is used. The primary decoding format is ASN.1, if an ASN.1 specification for these parameters exists.

Parameters
`params`	`byte`: the encoded parameters.
`format`	`String`: the name of the decoding scheme.

Throws
`IOException`	on decoding errors, or if this parameter object has already been initialized.

toString

Added in API level 1

 public final String toString ()

Returns a formatted string describing the parameters.

Returns
`String`	a formatted string describing the parameters, or null if this parameter object has not been initialized.