1 package com.google.polo.json; 2 3 /* 4 Copyright (c) 2002 JSON.org 5 6 Permission is hereby granted, free of charge, to any person obtaining a copy 7 of this software and associated documentation files (the "Software"), to deal 8 in the Software without restriction, including without limitation the rights 9 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 copies of the Software, and to permit persons to whom the Software is 11 furnished to do so, subject to the following conditions: 12 13 The above copyright notice and this permission notice shall be included in all 14 copies or substantial portions of the Software. 15 16 The Software shall be used for Good, not Evil. 17 18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 19 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 20 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 21 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 22 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 23 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 24 SOFTWARE. 25 */ 26 27 import java.util.Iterator; 28 29 30 /** 31 * This provides static methods to convert an XML text into a JSONObject, 32 * and to covert a JSONObject into an XML text. 33 * @author JSON.org 34 * @version 2008-10-14 35 */ 36 public class XML { 37 38 /** The Character '&'. */ 39 public static final Character AMP = new Character('&'); 40 41 /** The Character '''. */ 42 public static final Character APOS = new Character('\''); 43 44 /** The Character '!'. */ 45 public static final Character BANG = new Character('!'); 46 47 /** The Character '='. */ 48 public static final Character EQ = new Character('='); 49 50 /** The Character '>'. */ 51 public static final Character GT = new Character('>'); 52 53 /** The Character '<'. */ 54 public static final Character LT = new Character('<'); 55 56 /** The Character '?'. */ 57 public static final Character QUEST = new Character('?'); 58 59 /** The Character '"'. */ 60 public static final Character QUOT = new Character('"'); 61 62 /** The Character '/'. */ 63 public static final Character SLASH = new Character('/'); 64 65 /** 66 * Replace special characters with XML escapes: 67 * <pre> 68 * & <small>(ampersand)</small> is replaced by &amp; 69 * < <small>(less than)</small> is replaced by &lt; 70 * > <small>(greater than)</small> is replaced by &gt; 71 * " <small>(double quote)</small> is replaced by &quot; 72 * </pre> 73 * @param string The string to be escaped. 74 * @return The escaped string. 75 */ escape(String string)76 public static String escape(String string) { 77 StringBuffer sb = new StringBuffer(); 78 for (int i = 0, len = string.length(); i < len; i++) { 79 char c = string.charAt(i); 80 switch (c) { 81 case '&': 82 sb.append("&"); 83 break; 84 case '<': 85 sb.append("<"); 86 break; 87 case '>': 88 sb.append(">"); 89 break; 90 case '"': 91 sb.append("""); 92 break; 93 default: 94 sb.append(c); 95 } 96 } 97 return sb.toString(); 98 } 99 100 /** 101 * Throw an exception if the string contains whitespace. 102 * Whitespace is not allowed in tagNames and attributes. 103 * @param string 104 * @throws JSONException 105 */ noSpace(String string)106 public static void noSpace(String string) throws JSONException { 107 int i, length = string.length(); 108 if (length == 0) { 109 throw new JSONException("Empty string."); 110 } 111 for (i = 0; i < length; i += 1) { 112 if (Character.isWhitespace(string.charAt(i))) { 113 throw new JSONException("'" + string + 114 "' contains a space character."); 115 } 116 } 117 } 118 119 /** 120 * Scan the content following the named tag, attaching it to the context. 121 * @param x The XMLTokener containing the source string. 122 * @param context The JSONObject that will include the new material. 123 * @param name The tag name. 124 * @return true if the close tag is processed. 125 * @throws JSONException 126 */ parse(XMLTokener x, JSONObject context, String name)127 private static boolean parse(XMLTokener x, JSONObject context, 128 String name) throws JSONException { 129 char c; 130 int i; 131 String n; 132 JSONObject o = null; 133 String s; 134 Object t; 135 136 // Test for and skip past these forms: 137 // <!-- ... --> 138 // <! ... > 139 // <![ ... ]]> 140 // <? ... ?> 141 // Report errors for these forms: 142 // <> 143 // <= 144 // << 145 146 t = x.nextToken(); 147 148 // <! 149 150 if (t == BANG) { 151 c = x.next(); 152 if (c == '-') { 153 if (x.next() == '-') { 154 x.skipPast("-->"); 155 return false; 156 } 157 x.back(); 158 } else if (c == '[') { 159 t = x.nextToken(); 160 if (t.equals("CDATA")) { 161 if (x.next() == '[') { 162 s = x.nextCDATA(); 163 if (s.length() > 0) { 164 context.accumulate("content", s); 165 } 166 return false; 167 } 168 } 169 throw x.syntaxError("Expected 'CDATA['"); 170 } 171 i = 1; 172 do { 173 t = x.nextMeta(); 174 if (t == null) { 175 throw x.syntaxError("Missing '>' after '<!'."); 176 } else if (t == LT) { 177 i += 1; 178 } else if (t == GT) { 179 i -= 1; 180 } 181 } while (i > 0); 182 return false; 183 } else if (t == QUEST) { 184 185 // <? 186 187 x.skipPast("?>"); 188 return false; 189 } else if (t == SLASH) { 190 191 // Close tag </ 192 193 t = x.nextToken(); 194 if (name == null) { 195 throw x.syntaxError("Mismatched close tag" + t); 196 } 197 if (!t.equals(name)) { 198 throw x.syntaxError("Mismatched " + name + " and " + t); 199 } 200 if (x.nextToken() != GT) { 201 throw x.syntaxError("Misshaped close tag"); 202 } 203 return true; 204 205 } else if (t instanceof Character) { 206 throw x.syntaxError("Misshaped tag"); 207 208 // Open tag < 209 210 } else { 211 n = (String)t; 212 t = null; 213 o = new JSONObject(); 214 for (;;) { 215 if (t == null) { 216 t = x.nextToken(); 217 } 218 219 // attribute = value 220 221 if (t instanceof String) { 222 s = (String)t; 223 t = x.nextToken(); 224 if (t == EQ) { 225 t = x.nextToken(); 226 if (!(t instanceof String)) { 227 throw x.syntaxError("Missing value"); 228 } 229 o.accumulate(s, JSONObject.stringToValue((String)t)); 230 t = null; 231 } else { 232 o.accumulate(s, ""); 233 } 234 235 // Empty tag <.../> 236 237 } else if (t == SLASH) { 238 if (x.nextToken() != GT) { 239 throw x.syntaxError("Misshaped tag"); 240 } 241 context.accumulate(n, o); 242 return false; 243 244 // Content, between <...> and </...> 245 246 } else if (t == GT) { 247 for (;;) { 248 t = x.nextContent(); 249 if (t == null) { 250 if (n != null) { 251 throw x.syntaxError("Unclosed tag " + n); 252 } 253 return false; 254 } else if (t instanceof String) { 255 s = (String)t; 256 if (s.length() > 0) { 257 o.accumulate("content", JSONObject.stringToValue(s)); 258 } 259 260 // Nested element 261 262 } else if (t == LT) { 263 if (parse(x, o, n)) { 264 if (o.length() == 0) { 265 context.accumulate(n, ""); 266 } else if (o.length() == 1 && 267 o.opt("content") != null) { 268 context.accumulate(n, o.opt("content")); 269 } else { 270 context.accumulate(n, o); 271 } 272 return false; 273 } 274 } 275 } 276 } else { 277 throw x.syntaxError("Misshaped tag"); 278 } 279 } 280 } 281 } 282 283 284 /** 285 * Convert a well-formed (but not necessarily valid) XML string into a 286 * JSONObject. Some information may be lost in this transformation 287 * because JSON is a data format and XML is a document format. XML uses 288 * elements, attributes, and content text, while JSON uses unordered 289 * collections of name/value pairs and arrays of values. JSON does not 290 * does not like to distinguish between elements and attributes. 291 * Sequences of similar elements are represented as JSONArrays. Content 292 * text may be placed in a "content" member. Comments, prologs, DTDs, and 293 * <code><[ [ ]]></code> are ignored. 294 * @param string The source string. 295 * @return A JSONObject containing the structured data from the XML string. 296 * @throws JSONException 297 */ toJSONObject(String string)298 public static JSONObject toJSONObject(String string) throws JSONException { 299 JSONObject o = new JSONObject(); 300 XMLTokener x = new XMLTokener(string); 301 while (x.more() && x.skipPast("<")) { 302 parse(x, o, null); 303 } 304 return o; 305 } 306 307 308 /** 309 * Convert a JSONObject into a well-formed, element-normal XML string. 310 * @param o A JSONObject. 311 * @return A string. 312 * @throws JSONException 313 */ toString(Object o)314 public static String toString(Object o) throws JSONException { 315 return toString(o, null); 316 } 317 318 319 /** 320 * Convert a JSONObject into a well-formed, element-normal XML string. 321 * @param o A JSONObject. 322 * @param tagName The optional name of the enclosing tag. 323 * @return A string. 324 * @throws JSONException 325 */ toString(Object o, String tagName)326 public static String toString(Object o, String tagName) 327 throws JSONException { 328 StringBuffer b = new StringBuffer(); 329 int i; 330 JSONArray ja; 331 JSONObject jo; 332 String k; 333 Iterator keys; 334 int len; 335 String s; 336 Object v; 337 if (o instanceof JSONObject) { 338 339 // Emit <tagName> 340 341 if (tagName != null) { 342 b.append('<'); 343 b.append(tagName); 344 b.append('>'); 345 } 346 347 // Loop thru the keys. 348 349 jo = (JSONObject)o; 350 keys = jo.keys(); 351 while (keys.hasNext()) { 352 k = keys.next().toString(); 353 v = jo.opt(k); 354 if (v == null) { 355 v = ""; 356 } 357 if (v instanceof String) { 358 s = (String)v; 359 } else { 360 s = null; 361 } 362 363 // Emit content in body 364 365 if (k.equals("content")) { 366 if (v instanceof JSONArray) { 367 ja = (JSONArray)v; 368 len = ja.length(); 369 for (i = 0; i < len; i += 1) { 370 if (i > 0) { 371 b.append('\n'); 372 } 373 b.append(escape(ja.get(i).toString())); 374 } 375 } else { 376 b.append(escape(v.toString())); 377 } 378 379 // Emit an array of similar keys 380 381 } else if (v instanceof JSONArray) { 382 ja = (JSONArray)v; 383 len = ja.length(); 384 for (i = 0; i < len; i += 1) { 385 v = ja.get(i); 386 if (v instanceof JSONArray) { 387 b.append('<'); 388 b.append(k); 389 b.append('>'); 390 b.append(toString(v)); 391 b.append("</"); 392 b.append(k); 393 b.append('>'); 394 } else { 395 b.append(toString(v, k)); 396 } 397 } 398 } else if (v.equals("")) { 399 b.append('<'); 400 b.append(k); 401 b.append("/>"); 402 403 // Emit a new tag <k> 404 405 } else { 406 b.append(toString(v, k)); 407 } 408 } 409 if (tagName != null) { 410 411 // Emit the </tagname> close tag 412 413 b.append("</"); 414 b.append(tagName); 415 b.append('>'); 416 } 417 return b.toString(); 418 419 // XML does not have good support for arrays. If an array appears in a place 420 // where XML is lacking, synthesize an <array> element. 421 422 } else if (o instanceof JSONArray) { 423 ja = (JSONArray)o; 424 len = ja.length(); 425 for (i = 0; i < len; ++i) { 426 v = ja.opt(i); 427 b.append(toString(v, (tagName == null) ? "array" : tagName)); 428 } 429 return b.toString(); 430 } else { 431 s = (o == null) ? "null" : escape(o.toString()); 432 return (tagName == null) ? "\"" + s + "\"" : 433 (s.length() == 0) ? "<" + tagName + "/>" : 434 "<" + tagName + ">" + s + "</" + tagName + ">"; 435 } 436 } 437 }