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javax.crypto
public class: KeyGenerator [javadoc | source]
java.lang.Object
   javax.crypto.KeyGenerator
This class provides the functionality of a secret (symmetric) key generator.

Key generators are constructed using one of the getInstance class methods of this class.

KeyGenerator objects are reusable, i.e., after a key has been generated, the same KeyGenerator object can be re-used to generate further keys.

There are two ways to generate a key: in an algorithm-independent manner, and in an algorithm-specific manner. The only difference between the two is the initialization of the object:

In case the client does not explicitly initialize the KeyGenerator (via a call to an init method), each provider must supply (and document) a default initialization.

Every implementation of the Java platform is required to support the following standard KeyGenerator algorithms with the keysizes in parentheses:

These algorithms are described in the KeyGenerator section of the Java Cryptography Architecture Standard Algorithm Name Documentation. Consult the release documentation for your implementation to see if any other algorithms are supported.
Constructor:
 protected KeyGenerator(KeyGeneratorSpi keyGenSpi,
    Provider provider,
    String algorithm) 
    Creates a KeyGenerator object.
    Parameters:
    keyGenSpi - the delegate
    provider - the provider
    algorithm - the algorithm
Method from javax.crypto.KeyGenerator Summary:
disableFailover,   generateKey,   getAlgorithm,   getInstance,   getInstance,   getInstance,   getProvider,   init,   init,   init,   init,   init
Methods from java.lang.Object:
clone,   equals,   finalize,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from javax.crypto.KeyGenerator Detail:
  void disableFailover() 
 public final SecretKey generateKey() 
    Generates a secret key.
 public final String getAlgorithm() 
    Returns the algorithm name of this KeyGenerator object.

    This is the same name that was specified in one of the getInstance calls that created this KeyGenerator object.

 public static final KeyGenerator getInstance(String algorithm) throws NoSuchAlgorithmException 
    Returns a KeyGenerator object that generates secret keys for the specified algorithm.

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

 public static final KeyGenerator getInstance(String algorithm,
    String provider) throws NoSuchAlgorithmException, NoSuchProviderException 
    Returns a KeyGenerator object that generates secret keys for the specified algorithm.

    A new KeyGenerator object encapsulating the KeyGeneratorSpi 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.

 public static final KeyGenerator getInstance(String algorithm,
    Provider provider) throws NoSuchAlgorithmException 
    Returns a KeyGenerator object that generates secret keys for the specified algorithm.

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

 public final Provider getProvider() 
    Returns the provider of this KeyGenerator object.
 public final  void init(SecureRandom random) 
    Initializes this key generator.
 public final  void init(AlgorithmParameterSpec params) throws InvalidAlgorithmParameterException 
    Initializes this key generator with the specified parameter set.

    If this key generator requires any random bytes, it will get them using the SecureRandom implementation of the highest-priority installed provider as the source of randomness. (If none of the installed providers supply an implementation of SecureRandom, a system-provided source of randomness will be used.)

 public final  void init(int keysize) 
    Initializes this key generator for a certain keysize.

    If this key generator requires any random bytes, it will get them using the SecureRandom implementation of the highest-priority installed provider as the source of randomness. (If none of the installed providers supply an implementation of SecureRandom, a system-provided source of randomness will be used.)

 public final  void init(AlgorithmParameterSpec params,
    SecureRandom random) throws InvalidAlgorithmParameterException 
    Initializes this key generator with the specified parameter set and a user-provided source of randomness.
 public final  void init(int keysize,
    SecureRandom random) 
    Initializes this key generator for a certain keysize, using a user-provided source of randomness.