plugins/jibu-json/src/main/java/org/gaixie/jibu/json/XML.java

   1 package org.gaixie.jibu.json;
   2 /*
   3   Copyright (c) 2002 JSON.org
   4
   5   Permission is hereby granted, free of charge, to any person obtaining a copy
   6   of this software and associated documentation files (the "Software"), to deal
   7   in the Software without restriction, including without limitation the rights
   8   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   9   copies of the Software, and to permit persons to whom the Software is
  10   furnished to do so, subject to the following conditions:
  11
  12   The above copyright notice and this permission notice shall be included in all
  13   copies or substantial portions of the Software.
  14
  15   The Software shall be used for Good, not Evil.
  16
  17   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23   SOFTWARE.
  24 */
  25
  26 import java.util.Iterator;
  27
  28
  29 /**
  30  * This provides static methods to convert an XML text into a JSONObject,
  31  * and to covert a JSONObject into an XML text.
  32  * @author JSON.org
  33  * @version 2008-10-14
  34  */
  35 public class XML {
  36
  37     /** The Character '&'. */
  38     public static final Character AMP   = new Character('&');
  39
  40     /** The Character '''. */
  41     public static final Character APOS  = new Character('\'');
  42
  43     /** The Character '!'. */
  44     public static final Character BANG  = new Character('!');
  45
  46     /** The Character '='. */
  47     public static final Character EQ    = new Character('=');
  48
  49     /** The Character '>'. */
  50     public static final Character GT    = new Character('>');
  51
  52     /** The Character '<'. */
  53     public static final Character LT    = new Character('<');
  54
  55     /** The Character '?'. */
  56     public static final Character QUEST = new Character('?');
  57
  58     /** The Character '"'. */
  59     public static final Character QUOT  = new Character('"');
  60
  61     /** The Character '/'. */
  62     public static final Character SLASH = new Character('/');
  63
  64     /**
  65      * Replace special characters with XML escapes:
  66      * <pre>
  67      * &amp; <small>(ampersand)</small> is replaced by &amp;amp;
  68      * &lt; <small>(less than)</small> is replaced by &amp;lt;
  69      * &gt; <small>(greater than)</small> is replaced by &amp;gt;
  70      * &quot; <small>(double quote)</small> is replaced by &amp;quot;
  71      * </pre>
  72      * @param string The string to be escaped.
  73      * @return The escaped string.
  74      */
  75     public static String escape(String string) {
  76         StringBuffer sb = new StringBuffer();
  77         for (int i = 0, len = string.length(); i < len; i++) {
  78             char c = string.charAt(i);
  79             switch (c) {
  80             case '&':
  81                 sb.append("&amp;");
  82                 break;
  83             case '<':
  84                 sb.append("&lt;");
  85                 break;
  86             case '>':
  87                 sb.append("&gt;");
  88                 break;
  89             case '"':
  90                 sb.append("&quot;");
  91                 break;
  92             default:
  93                 sb.append(c);
  94             }
  95         }
  96         return sb.toString();
  97     }
  98
  99     /**
 100      * Throw an exception if the string contains whitespace.
 101      * Whitespace is not allowed in tagNames and attributes.
 102      * @param string
 103      * @throws JSONException
 104      */
 105     public static void noSpace(String string) throws JSONException {
 106         int i, length = string.length();
 107         if (length == 0) {
 108             throw new JSONException("Empty string.");
 109         }
 110         for (i = 0; i < length; i += 1) {
 111             if (Character.isWhitespace(string.charAt(i))) {
 112                 throw new JSONException("'" + string +
 113                                         "' contains a space character.");
 114             }
 115         }
 116     }
 117
 118     /**
 119      * Scan the content following the named tag, attaching it to the context.
 120      * @param x       The XMLTokener containing the source string.
 121      * @param context The JSONObject that will include the new material.
 122      * @param name    The tag name.
 123      * @return true if the close tag is processed.
 124      * @throws JSONException
 125      */
 126     private static boolean parse(XMLTokener x, JSONObject context,
 127                                  String name) throws JSONException {
 128         char       c;
 129         int        i;
 130         String     n;
 131         JSONObject o = null;
 132         String     s;
 133         Object     t;
 134
 135         // Test for and skip past these forms:
 136         //      <!-- ... -->
 137         //      <!   ...   >
 138         //      <![  ... ]]>
 139         //      <?   ...  ?>
 140         // Report errors for these forms:
 141         //      <>
 142         //      <=
 143         //      <<
 144
 145         t = x.nextToken();
 146
 147         // <!
 148
 149         if (t == BANG) {
 150             c = x.next();
 151             if (c == '-') {
 152                 if (x.next() == '-') {
 153                     x.skipPast("-->");
 154                     return false;
 155                 }
 156                 x.back();
 157             } else if (c == '[') {
 158                 t = x.nextToken();
 159                 if (t.equals("CDATA")) {
 160                     if (x.next() == '[') {
 161                         s = x.nextCDATA();
 162                         if (s.length() > 0) {
 163                             context.accumulate("content", s);
 164                         }
 165                         return false;
 166                     }
 167                 }
 168                 throw x.syntaxError("Expected 'CDATA['");
 169             }
 170             i = 1;
 171             do {
 172                 t = x.nextMeta();
 173                 if (t == null) {
 174                     throw x.syntaxError("Missing '>' after '<!'.");
 175                 } else if (t == LT) {
 176                     i += 1;
 177                 } else if (t == GT) {
 178                     i -= 1;
 179                 }
 180             } while (i > 0);
 181             return false;
 182         } else if (t == QUEST) {
 183
 184             // <?
 185
 186             x.skipPast("?>");
 187             return false;
 188         } else if (t == SLASH) {
 189
 190             // Close tag </
 191
 192             t = x.nextToken();
 193             if (name == null) {
 194                 throw x.syntaxError("Mismatched close tag" + t);
 195             }
 196             if (!t.equals(name)) {
 197                 throw x.syntaxError("Mismatched " + name + " and " + t);
 198             }
 199             if (x.nextToken() != GT) {
 200                 throw x.syntaxError("Misshaped close tag");
 201             }
 202             return true;
 203
 204         } else if (t instanceof Character) {
 205             throw x.syntaxError("Misshaped tag");
 206
 207             // Open tag <
 208
 209         } else {
 210             n = (String)t;
 211             t = null;
 212             o = new JSONObject();
 213             for (;;) {
 214                 if (t == null) {
 215                     t = x.nextToken();
 216                 }
 217
 218                 // attribute = value
 219
 220                 if (t instanceof String) {
 221                     s = (String)t;
 222                     t = x.nextToken();
 223                     if (t == EQ) {
 224                         t = x.nextToken();
 225                         if (!(t instanceof String)) {
 226                             throw x.syntaxError("Missing value");
 227                         }
 228                         o.accumulate(s, JSONObject.stringToValue((String)t));
 229                         t = null;
 230                     } else {
 231                         o.accumulate(s, "");
 232                     }
 233
 234                     // Empty tag <.../>
 235
 236                 } else if (t == SLASH) {
 237                     if (x.nextToken() != GT) {
 238                         throw x.syntaxError("Misshaped tag");
 239                     }
 240                     context.accumulate(n, o);
 241                     return false;
 242
 243                     // Content, between <...> and </...>
 244
 245                 } else if (t == GT) {
 246                     for (;;) {
 247                         t = x.nextContent();
 248                         if (t == null) {
 249                             if (n != null) {
 250                                 throw x.syntaxError("Unclosed tag " + n);
 251                             }
 252                             return false;
 253                         } else if (t instanceof String) {
 254                             s = (String)t;
 255                             if (s.length() > 0) {
 256                                 o.accumulate("content", JSONObject.stringToValue(s));
 257                             }
 258
 259                             // Nested element
 260
 261                         } else if (t == LT) {
 262                             if (parse(x, o, n)) {
 263                                 if (o.length() == 0) {
 264                                     context.accumulate(n, "");
 265                                 } else if (o.length() == 1 &&
 266                                            o.opt("content") != null) {
 267                                     context.accumulate(n, o.opt("content"));
 268                                 } else {
 269                                     context.accumulate(n, o);
 270                                 }
 271                                 return false;
 272                             }
 273                         }
 274                     }
 275                 } else {
 276                     throw x.syntaxError("Misshaped tag");
 277                 }
 278             }
 279         }
 280     }
 281
 282
 283     /**
 284      * Convert a well-formed (but not necessarily valid) XML string into a
 285      * JSONObject. Some information may be lost in this transformation
 286      * because JSON is a data format and XML is a document format. XML uses
 287      * elements, attributes, and content text, while JSON uses unordered
 288      * collections of name/value pairs and arrays of values. JSON does not
 289      * does not like to distinguish between elements and attributes.
 290      * Sequences of similar elements are represented as JSONArrays. Content
 291      * text may be placed in a "content" member. Comments, prologs, DTDs, and
 292      * <code>&lt;[ [ ]]></code> are ignored.
 293      * @param string The source string.
 294      * @return A JSONObject containing the structured data from the XML string.
 295      * @throws JSONException
 296      */
 297     public static JSONObject toJSONObject(String string) throws JSONException {
 298         JSONObject o = new JSONObject();
 299         XMLTokener x = new XMLTokener(string);
 300         while (x.more() && x.skipPast("<")) {
 301             parse(x, o, null);
 302         }
 303         return o;
 304     }
 305
 306
 307     /**
 308      * Convert a JSONObject into a well-formed, element-normal XML string.
 309      * @param o A JSONObject.
 310      * @return  A string.
 311      * @throws  JSONException
 312      */
 313     public static String toString(Object o) throws JSONException {
 314         return toString(o, null);
 315     }
 316
 317
 318     /**
 319      * Convert a JSONObject into a well-formed, element-normal XML string.
 320      * @param o A JSONObject.
 321      * @param tagName The optional name of the enclosing tag.
 322      * @return A string.
 323      * @throws JSONException
 324      */
 325     public static String toString(Object o, String tagName)
 326         throws JSONException {
 327         StringBuffer b = new StringBuffer();
 328         int          i;
 329         JSONArray    ja;
 330         JSONObject   jo;
 331         String       k;
 332         Iterator     keys;
 333         int          len;
 334         String       s;
 335         Object       v;
 336         if (o instanceof JSONObject) {
 337
 338             // Emit <tagName>
 339
 340             if (tagName != null) {
 341                 b.append('<');
 342                 b.append(tagName);
 343                 b.append('>');
 344             }
 345
 346             // Loop thru the keys.
 347
 348             jo = (JSONObject)o;
 349             keys = jo.keys();
 350             while (keys.hasNext()) {
 351                 k = keys.next().toString();
 352                 v = jo.opt(k);
 353                 if (v == null) {
 354                     v = "";
 355                 }
 356                 if (v instanceof String) {
 357                     s = (String)v;
 358                 } else {
 359                     s = null;
 360                 }
 361
 362                 // Emit content in body
 363
 364                 if (k.equals("content")) {
 365                     if (v instanceof JSONArray) {
 366                         ja = (JSONArray)v;
 367                         len = ja.length();
 368                         for (i = 0; i < len; i += 1) {
 369                             if (i > 0) {
 370                                 b.append('\n');
 371                             }
 372                             b.append(escape(ja.get(i).toString()));
 373                         }
 374                     } else {
 375                         b.append(escape(v.toString()));
 376                     }
 377
 378                     // Emit an array of similar keys
 379
 380                 } else if (v instanceof JSONArray) {
 381                     ja = (JSONArray)v;
 382                     len = ja.length();
 383                     for (i = 0; i < len; i += 1) {
 384                         v = ja.get(i);
 385                         if (v instanceof JSONArray) {
 386                             b.append('<');
 387                             b.append(k);
 388                             b.append('>');
 389                             b.append(toString(v));
 390                             b.append("</");
 391                             b.append(k);
 392                             b.append('>');
 393                         } else {
 394                             b.append(toString(v, k));
 395                         }
 396                     }
 397                 } else if (v.equals("")) {
 398                     b.append('<');
 399                     b.append(k);
 400                     b.append("/>");
 401
 402                     // Emit a new tag <k>
 403
 404                 } else {
 405                     b.append(toString(v, k));
 406                 }
 407             }
 408             if (tagName != null) {
 409
 410                 // Emit the </tagname> close tag
 411
 412                 b.append("</");
 413                 b.append(tagName);
 414                 b.append('>');
 415             }
 416             return b.toString();
 417
 418             // XML does not have good support for arrays. If an array appears in a place
 419             // where XML is lacking, synthesize an <array> element.
 420
 421         } else if (o instanceof JSONArray) {
 422             ja = (JSONArray)o;
 423             len = ja.length();
 424             for (i = 0; i < len; ++i) {
 425                 v = ja.opt(i);
 426                 b.append(toString(v, (tagName == null) ? "array" : tagName));
 427             }
 428             return b.toString();
 429         } else {
 430             s = (o == null) ? "null" : escape(o.toString());
 431             return (tagName == null) ? "\"" + s + "\"" :
 432                 (s.length() == 0) ? "<" + tagName + "/>" :
 433                 "<" + tagName + ">" + s + "</" + tagName + ">";
 434         }
 435     }
 436 }