String for under a particular Collator. This
* value may be compared bitwise against another CollationKey
* representing a different String under the same
* Collator in a manner than is usually more efficient than
* using the raw Collator compare methods. There is overhead
* associated with calculating this value, so it is generally not
* advisable to compute CollationKey's unless multiple
* comparisons against a String will be done. (For example,
* in a sort routine).
*
* This class cannot be instantiated directly. Instead, a
*
* CollationKey is created by calling the
* getCollationKey method on an instance of Collator.
*
* @author Aaron M. Renn String this object represents.
*/
private String originalText;
/**
* This is the bit value for this key.
*/
private int[] key;
CollationKey (CollationElementIterator iter, String originalText,
int strength)
{
this.originalText = originalText;
// Compute size of required array.
int size = 0;
while (RuleBasedCollator.next(iter, strength)
!= CollationElementIterator.NULLORDER)
++size;
iter.reset();
key = new int[size];
for (int i = 0; i < size; i++)
key[i] = RuleBasedCollator.next(iter, strength);
}
/**
* This method compares the specified object to this one. An integer is
* returned which indicates whether the specified object is less than,
* greater than, or equal to this object.
*
* @param ck The CollationKey to compare against this one.
*
* @return A negative integer if this object is less than the specified object, 0 if it is equal or a positive integer if it is greater than the specified object.
*/
public int compareTo (CollationKey ck)
{
int max = Math.min (key.length, ck.key.length);
for (int i = 0; i < max; ++i)
{
if (key[i] != ck.key[i])
return key[i] - ck.key[i];
}
return key.length - ck.key.length;
}
/**
* This method compares the specified object to this one. The specified
* object must be an instance of CollationKey or an exception
* will be thrown. An integer is returned which indicates whether the
* specified object is less than, greater than, or equal to this object.
*
* @param obj The Object to compare against this one.
*
* @return A negative integer if this object is less than the specified object, 0 if it is equal or a positive integer if it is greater than the specified object.
*/
public int compareTo (Object obj)
{
return compareTo ((CollationKey) obj);
}
/**
* This method tests the specified Object for equality with
* this object. This will be true if and only if:
*
*
*
* @param obj The null
* CollationKey.
* Collator
* as this object.
* Object to test for equality.
*
* @return true if the specified object is equal to this one, false otherwise.
*/
public boolean equals (Object obj)
{
if (! (obj instanceof CollationKey))
return false;
CollationKey ck = (CollationKey) obj;
if (key.length != ck.key.length)
return false;
for (int i = 0; i < key.length; ++i)
if (key[i] != ck.key[i])
return false;
return true;
}
/**
* This method returns the String that this object was created
* from.
*
* @return The source String for this object.
*/
public String getSourceString ()
{
return originalText;
}
/**
* This method returns a hash value for this object. The hash value
* returned will be the hash code of the bit key so that identical bit
* keys will return the same value.
*
* @return A hash value for this object.
*/
public int hashCode ()
{
// We just follow BitSet instead of thinking up something new.
long h = originalText.hashCode();
for (int i = key.length - 1; i >= 0; --i)
h ^= key[i] * (i + 1);
return (int) ((h >> 32) ^ h);
}
/**
* This method returns the collation bit sequence as a byte array.
*
* @param A byte array containing the collation bit sequence.
*/
public byte[] toByteArray ()
{
byte[] r = new byte[4 * key.length];
int off = 0;
for (int i = 0; i < key.length; ++i)
{
r[off++] = (byte) ((key[i] >>> 24) & 255);
r[off++] = (byte) ((key[i] >>> 16) & 255);
r[off++] = (byte) ((key[i] >>> 8) & 255);
r[off++] = (byte) ((key[i] ) & 255);
}
return r;
}
}