protected int hash ( Object key ) { // same as JDK 1.4 int h = key . hashCode ( ) ; h += ~ ( h << 9 ) ; h ^= ( h >>> 14 ) ; h += ( h << 4 ) ; h ^= ( h >>> 10 ) ; return h ; }
Gets the hash code for the key specified . This implementation uses the additional hashing routine from JDK1 . 4 . Subclasses can override this to return alternate hash codes .