/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the  "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
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/*
 * $Id: StringComparable.java 468655 2006-10-28 07:12:06Z minchau $
 */

package org.apache.xml.utils;

import java.util.Vector;
import java.text.Collator;
import java.text.RuleBasedCollator;
import java.text.CollationElementIterator;
import java.util.Locale;
import java.text.CollationKey;


International friendly string comparison with case-order
Author:Igor Hersht, igorh@ca.ibm.com
/** * International friendly string comparison with case-order * @author Igor Hersht, igorh@ca.ibm.com */
public class StringComparable implements Comparable { public final static int UNKNOWN_CASE = -1; public final static int UPPER_CASE = 1; public final static int LOWER_CASE = 2; private String m_text; private Locale m_locale; private RuleBasedCollator m_collator; private String m_caseOrder; private int m_mask = 0xFFFFFFFF; public StringComparable(final String text, final Locale locale, final Collator collator, final String caseOrder){ m_text = text; m_locale = locale; m_collator = (RuleBasedCollator)collator; m_caseOrder = caseOrder; m_mask = getMask(m_collator.getStrength()); } public final static Comparable getComparator( final String text, final Locale locale, final Collator collator, final String caseOrder){ if((caseOrder == null) ||(caseOrder.length() == 0)){// no case-order specified return ((RuleBasedCollator)collator).getCollationKey(text); }else{ return new StringComparable(text, locale, collator, caseOrder); } } public final String toString(){return m_text;} public int compareTo(Object o) { final String pattern = ((StringComparable)o).toString(); if(m_text.equals(pattern)){//Code-point equals return 0; } final int savedStrength = m_collator.getStrength(); int comp = 0; // Is there difference more significant than case-order? if(((savedStrength == Collator.PRIMARY) || (savedStrength == Collator.SECONDARY))){ comp = m_collator.compare(m_text, pattern ); }else{// more than SECONDARY m_collator.setStrength(Collator.SECONDARY); comp = m_collator.compare(m_text, pattern ); m_collator.setStrength(savedStrength); } if(comp != 0){//Difference more significant than case-order return comp ; } // No difference more significant than case-order. // Find case difference comp = getCaseDiff(m_text, pattern); if(comp != 0){ return comp; }else{// No case differences. Less significant difference could exist return m_collator.compare(m_text, pattern ); } } private final int getCaseDiff (final String text, final String pattern){ final int savedStrength = m_collator.getStrength(); final int savedDecomposition = m_collator.getDecomposition(); m_collator.setStrength(Collator.TERTIARY);// not to ignore case m_collator.setDecomposition(Collator.CANONICAL_DECOMPOSITION );// corresponds NDF final int diff[] =getFirstCaseDiff (text, pattern, m_locale); m_collator.setStrength(savedStrength);// restore m_collator.setDecomposition(savedDecomposition); //restore if(diff != null){ if((m_caseOrder).equals("upper-first")){ if(diff[0] == UPPER_CASE){ return -1; }else{ return 1; } }else{// lower-first if(diff[0] == LOWER_CASE){ return -1; }else{ return 1; } } }else{// No case differences return 0; } } private final int[] getFirstCaseDiff(final String text, final String pattern, final Locale locale){ final CollationElementIterator targIter = m_collator.getCollationElementIterator(text); final CollationElementIterator patIter = m_collator.getCollationElementIterator(pattern); int startTarg = -1; int endTarg = -1; int startPatt = -1; int endPatt = -1; final int done = getElement(CollationElementIterator.NULLORDER); int patternElement = 0, targetElement = 0; boolean getPattern = true, getTarget = true; while (true) { if (getPattern){ startPatt = patIter.getOffset(); patternElement = getElement(patIter.next()); endPatt = patIter.getOffset(); } if ((getTarget)){ startTarg = targIter.getOffset(); targetElement = getElement(targIter.next()); endTarg = targIter.getOffset(); } getTarget = getPattern = true; if ((patternElement == done) ||( targetElement == done)) { return null; } else if (targetElement == 0) { getPattern = false; } else if (patternElement == 0) { getTarget = false; } else if (targetElement != patternElement) {// mismatch if((startPatt < endPatt) && (startTarg < endTarg)){ final String subText = text.substring(startTarg, endTarg); final String subPatt = pattern.substring(startPatt, endPatt); final String subTextUp = subText.toUpperCase(locale); final String subPattUp = subPatt.toUpperCase(locale); if(m_collator.compare(subTextUp, subPattUp) != 0){ // not case diffference continue; } int diff[] = {UNKNOWN_CASE, UNKNOWN_CASE}; if(m_collator.compare(subText, subTextUp) == 0){ diff[0] = UPPER_CASE; }else if(m_collator.compare(subText, subText.toLowerCase(locale)) == 0){ diff[0] = LOWER_CASE; } if(m_collator.compare(subPatt, subPattUp) == 0){ diff[1] = UPPER_CASE; }else if(m_collator.compare(subPatt, subPatt.toLowerCase(locale)) == 0){ diff[1] = LOWER_CASE; } if(((diff[0] == UPPER_CASE) && ( diff[1] == LOWER_CASE)) || ((diff[0] == LOWER_CASE) && ( diff[1] == UPPER_CASE))){ return diff; }else{// not case diff continue; } }else{ continue; } } } } // Return a mask for the part of the order we're interested in private static final int getMask(final int strength) { switch (strength) { case Collator.PRIMARY: return 0xFFFF0000; case Collator.SECONDARY: return 0xFFFFFF00; default: return 0xFFFFFFFF; } } //get collation element with given strength // from the element with max strength private final int getElement(int maxStrengthElement){ return (maxStrengthElement & m_mask); } }//StringComparable