code: public final Key getKey(String alias, char[] password)
          throws KeyStoreException, NoSuchAlgorithmException,
              UnrecoverableKeyException
      {
          if (!initialized) {
              throw new KeyStoreException("Uninitialized keystore");
          }
          return keyStoreSpi.engineGetKey(alias, password);
      }
docs: Returns the key associated with the given alias, using the given
  password to recover it.  The key must have been associated with
  the alias by a call to <code>setKeyEntry</code>,
  or by a call to <code>setEntry</code> with a
  <code>PrivateKeyEntry</code> or <code>SecretKeyEntry</code>.
  
  @param alias the alias name
  @param password the password for recovering the key
  
  @return the requested key, or null if the given alias does not exist
  or does not identify a key-related entry.
  
  @exception KeyStoreException if the keystore has not been initialized
  (loaded).
  @exception NoSuchAlgorithmException if the algorithm for recovering the
  key cannot be found
  @exception UnrecoverableKeyException if the key cannot be recovered
  (e.g., the given password is wrong).