javax.crypto.spec
Class SecretKeySpec

java.lang.Object
  extended by javax.crypto.spec.SecretKeySpec
All Implemented Interfaces:
Serializable, Key, KeySpec, SecretKey

public class SecretKeySpec
extends Object
implements KeySpec, SecretKey

This is a simple wrapper around a raw byte array, for ciphers that do not require any key parameters other than the bytes themselves.

Since this class implements SecretKey, which in turn extends Key, so instances of this class may be passed directly to the init() methods of Cipher.

See Also:
SecretKey, SecretKeyFactory, Serialized Form

Constructor Summary
SecretKeySpec(byte[] key, int off, int len, String algorithm)
          Create a new secret key spec from part of a byte array.
SecretKeySpec(byte[] key, String algorithm)
          Create a new secret key spec from an entire byte array.
 
Method Summary
 boolean equals(Object o)
          Determine whether this Object is semantically equal to another Object.
 String getAlgorithm()
          Return the name of the algorithm associated with this secret key.
 byte[] getEncoded()
          Return the key as a byte array.
 String getFormat()
          This key's format, which is always "RAW".
 int hashCode()
          Get a value that represents this Object, as uniquely as possible within the confines of an int.
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

SecretKeySpec

public SecretKeySpec(byte[] key,
                     String algorithm)
Create a new secret key spec from an entire byte array.

Parameters:
key - The key material.
algorithm - The name of the algorithm using this key.

SecretKeySpec

public SecretKeySpec(byte[] key,
                     int off,
                     int len,
                     String algorithm)
Create a new secret key spec from part of a byte array.

Parameters:
key - The key material.
off - The offset at which key material begins.
len - The length of key material.
algorithm - The name of the algorithm using this key.
Method Detail

getAlgorithm

public String getAlgorithm()
Return the name of the algorithm associated with this secret key.

Specified by:
getAlgorithm in interface Key
Returns:
The algorithm's name.

getEncoded

public byte[] getEncoded()
Return the key as a byte array.

Specified by:
getEncoded in interface Key
Returns:
The key material.

getFormat

public String getFormat()
This key's format, which is always "RAW".

Specified by:
getFormat in interface Key
Returns:
"RAW"

equals

public boolean equals(Object o)
Description copied from class: Object
Determine whether this Object is semantically equal to another Object.

There are some fairly strict requirements on this method which subclasses must follow:

This is typically overridden to throw a ClassCastException if the argument is not comparable to the class performing the comparison, but that is not a requirement. It is legal for a.equals(b) to be true even though a.getClass() != b.getClass(). Also, it is typical to never cause a NullPointerException.

In general, the Collections API (java.util) use the equals method rather than the == operator to compare objects. However, IdentityHashMap is an exception to this rule, for its own good reasons.

The default implementation returns this == o.

Overrides:
equals in class Object
Parameters:
o - the Object to compare to
Returns:
whether this Object is semantically equal to another
See Also:
Object.hashCode()

hashCode

public int hashCode()
Description copied from class: Object
Get a value that represents this Object, as uniquely as possible within the confines of an int.

There are some requirements on this method which subclasses must follow:

Notice that since hashCode is used in Hashtable and other hashing classes, a poor implementation will degrade the performance of hashing (so don't blindly implement it as returning a constant!). Also, if calculating the hash is time-consuming, a class may consider caching the results.

The default implementation returns System.identityHashCode(this)

Overrides:
hashCode in class Object
Returns:
the hash code for this Object
See Also:
Object.equals(Object), System.identityHashCode(Object)