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      1 //  2016 and later: Unicode, Inc. and others.
      2 // License & terms of use: http://www.unicode.org/copyright.html#License
      3 /**
      4  *******************************************************************************
      5  * Copyright (C) 2001-2013, International Business Machines Corporation and    *
      6  * others. All Rights Reserved.                                                *
      7  *******************************************************************************
      8  */
      9 package com.ibm.icu.util;
     10 
     11 import com.ibm.icu.lang.UCharacter;
     12 
     13 /**
     14  * A string used as a key in java.util.Hashtable and other
     15  * collections.  It retains case information, but its equals() and
     16  * hashCode() methods ignore case.
     17  * @stable ICU 2.0
     18  */
     19 public class CaseInsensitiveString {
     20 
     21     private String string;
     22 
     23     private int hash = 0;
     24 
     25     private String folded = null;
     26 
     27     private static String foldCase(String foldee)
     28     {
     29         return UCharacter.foldCase(foldee, true);
     30     }
     31 
     32     private void getFolded()
     33     {
     34         if (folded == null) {
     35             folded = foldCase(string);
     36         }
     37     }
     38 
     39     /**
     40      * Constructs an CaseInsentiveString object from the given string
     41      * @param s The string to construct this object from
     42      * @stable ICU 2.0
     43      */
     44     public CaseInsensitiveString(String s) {
     45         string = s;
     46     }
     47     /**
     48      * returns the underlying string
     49      * @return String
     50      * @stable ICU 2.0
     51      */
     52     public String getString() {
     53         return string;
     54     }
     55     /**
     56      * Compare the object with this
     57      * @param o Object to compare this object with
     58      * @stable ICU 2.0
     59      */
     60     public boolean equals(Object o) {
     61         if (o == null) {
     62             return false;
     63         }
     64         if (this == o) {
     65             return true;
     66         }
     67         if (o instanceof CaseInsensitiveString) {
     68             getFolded();
     69             CaseInsensitiveString cis = (CaseInsensitiveString) o;
     70             cis.getFolded();
     71             return folded.equals(cis.folded);
     72         }
     73         return false;
     74     }
     75 
     76     /**
     77      * Returns the hashCode of this object
     78      * @return int hashcode
     79      * @stable ICU 2.0
     80      */
     81     public int hashCode() {
     82         getFolded();
     83 
     84         if (hash == 0) {
     85             hash = folded.hashCode();
     86         }
     87 
     88         return hash;
     89     }
     90 
     91     /**
     92      * Overrides superclass method
     93      * @stable ICU 3.6
     94      */
     95     public String toString() {
     96         return string;
     97     }
     98 }
     99