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SecureRandomSpi (Java Platform SE 6) - JDK 5 Documentation v6.0, Java 2 SDK 英文文档


Java™ Platform
Standard Ed. 6

java.security
Class SecureRandomSpi

java.lang.Object
  extended by java.security.SecureRandomSpi
All Implemented Interfaces:
Serializable

public abstract class SecureRandomSpi
extends Object
implements Serializable

This class defines the Service Provider Interface (SPI) for the SecureRandom class. All the abstract methods in this class must be implemented by each service provider who wishes to supply the implementation of a cryptographically strong pseudo-random number generator.

Since:
1.2
See Also:
SecureRandom, Serialized Form

Constructor Summary
SecureRandomSpi()
           
 
Method Summary
protected abstract  byte[] engineGenerateSeed(int numBytes)
          Returns the given number of seed bytes.
protected abstract  void engineNextBytes(byte[] bytes)
          Generates a user-specified number of random bytes.
protected abstract  void engineSetSeed(byte[] seed)
          Reseeds this random object.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

SecureRandomSpi

public SecureRandomSpi()
Method Detail

engineSetSeed

protected abstract void engineSetSeed(byte[] seed)
Reseeds this random object. The given seed supplements, rather than replaces, the existing seed. Thus, repeated calls are guaranteed never to reduce randomness.

Parameters:
seed - the seed.

engineNextBytes

protected abstract void engineNextBytes(byte[] bytes)
Generates a user-specified number of random bytes.

If a call to engineSetSeed had not occurred previously, the first call to this method forces this SecureRandom implementation to seed itself. This self-seeding will not occur if engineSetSeed was previously called.

Parameters:
bytes - the array to be filled in with random bytes.

engineGenerateSeed

protected abstract byte[] engineGenerateSeed(int numBytes)
Returns the given number of seed bytes. This call may be used to seed other random number generators.

Parameters:
numBytes - the number of seed bytes to generate.
Returns:
the seed bytes.

Java™ Platform
Standard Ed. 6

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For further API reference and developer documentation, see Java SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Copyright 2006 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.