| /* CollationKey.java -- Precomputed collation value |
| Copyright (C) 1998, 1999, 2000, 2003, 2005 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package java.text; |
| |
| import java.util.Arrays; |
| |
| /* Written using "Java Class Libraries", 2nd edition, plus online |
| * API docs for JDK 1.2 from http://www.javasoft.com. |
| * Status: Believed complete and correct. |
| */ |
| |
| /** |
| * This class represents a pre-computed series of bits representing a |
| * <code>String</code> for under a particular <code>Collator</code>. This |
| * value may be compared bitwise against another <code>CollationKey</code> |
| * representing a different <code>String</code> under the same |
| * <code>Collator</code> in a manner than is usually more efficient than |
| * using the raw <code>Collator</code> compare methods. There is overhead |
| * associated with calculating this value, so it is generally not |
| * advisable to compute <code>CollationKey</code>'s unless multiple |
| * comparisons against a <code>String</code> will be done. (For example, |
| * in a sort routine). |
| * <p> |
| * This class cannot be instantiated directly. Instead, a |
| * <code>CollationKey</code> is created by calling the |
| * <code>getCollationKey</code> method on an instance of <code>Collator</code>. |
| * |
| * @author Aaron M. Renn (arenn@urbanophile.com) |
| * @author Tom Tromey (tromey@cygnus.com) |
| * @date March 25, 1999 |
| */ |
| public final class CollationKey implements Comparable |
| { |
| /** |
| * This is the <code>Collator</code> this object was created from. |
| */ |
| private Collator collator; |
| |
| /** |
| * This is the <code>String</code> this object represents. |
| */ |
| private String originalText; |
| |
| /** |
| * This is the bit value for this key. |
| */ |
| private byte[] key; |
| |
| CollationKey (Collator collator, String originalText, byte[] key) |
| { |
| this.collator = collator; |
| this.originalText = originalText; |
| this.key = key; |
| } |
| |
| /** |
| * 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 <code>CollationKey</code> 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 <code>CollationKey</code> 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 <code>Object</code> 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 <code>Object</code> for equality with |
| * this object. This will be true if and only if: |
| * <p> |
| * <ul> |
| * <li>The specified object must not be <code>null</code></li> |
| * <li>The specified object is an instance of <code>CollationKey</code>.</li> |
| * <li>The specified object was created from the same <code>Collator</code> |
| * as this object.</li> |
| * <li>The specified object has the same source string and bit key as |
| * this object.</li> |
| * </ul> |
| * |
| * @param obj The <code>Object</code> to test for equality. |
| * |
| * @return <code>true</code> if the specified object is equal to this one, <code>false</code> otherwise. |
| */ |
| public boolean equals (Object obj) |
| { |
| if (! (obj instanceof CollationKey)) |
| return false; |
| |
| CollationKey ck = (CollationKey) obj; |
| |
| if (ck.collator != collator) |
| return false; |
| |
| if (!ck.getSourceString ().equals (getSourceString ())) |
| return false; |
| |
| if (! Arrays.equals (ck.toByteArray (), toByteArray ())) |
| return false; |
| |
| return true; |
| } |
| |
| /** |
| * This method returns the <code>String</code> that this object was created |
| * from. |
| * |
| * @return The source <code>String</code> 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. |
| * |
| * @return A byte array containing the collation bit sequence. |
| */ |
| public byte[] toByteArray() |
| { |
| return key; |
| } |
| } |