1 /*
   2  * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.xml.internal.messaging.saaj.util;
  27 
  28 
  29 // Cut&paste from sun.net.www.ParseUtil: decode, unescape
  30 
  31 public class ParseUtil {
  32     /**
  33      * Un-escape and return the character at position i in string s.
  34      */
  35     private static char unescape(String s, int i) {
  36         return (char) Integer.parseInt(s.substring(i+1,i+3),16);
  37     }
  38 
  39     /**
  40      * Returns a new String constructed from the specified String by replacing
  41      * the URL escape sequences and UTF8 encoding with the characters they
  42      * represent.
  43      *
  44      * @param s string
  45      *
  46      * @return decoded string
  47      */
  48     public static String decode(String s) {
  49         StringBuilder sb = new StringBuilder();
  50 
  51         int i=0;
  52         while (i<s.length()) {
  53             char c = s.charAt(i);
  54             char c2, c3;
  55 
  56             if (c != '%') {
  57                 i++;
  58             } else {
  59                 try {
  60                     c = unescape(s, i);
  61                     i += 3;
  62 
  63                     if ((c & 0x80) != 0) {
  64                         switch (c >> 4) {
  65                             case 0xC: case 0xD:
  66                                 c2 = unescape(s, i);
  67                                 i += 3;
  68                                 c = (char)(((c & 0x1f) << 6) | (c2 & 0x3f));
  69                                 break;
  70 
  71                             case 0xE:
  72                                 c2 = unescape(s, i);
  73                                 i += 3;
  74                                 c3 = unescape(s, i);
  75                                 i += 3;
  76                                 c = (char)(((c & 0x0f) << 12) |
  77                                            ((c2 & 0x3f) << 6) |
  78                                             (c3 & 0x3f));
  79                                 break;
  80 
  81                             default:
  82                                 throw new IllegalArgumentException();
  83                         }
  84                     }
  85                 } catch (NumberFormatException e) {
  86                     throw new IllegalArgumentException();
  87                 }
  88             }
  89 
  90             sb.append(c);
  91         }
  92 
  93         return sb.toString();
  94     }
  95 
  96 
  97 }