| 1 | /* |
| 2 | * Copyright (C) 2010 Google Inc. |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package com.google.gson.stream; |
| 18 | |
| 19 | import com.google.gson.internal.JsonReaderInternalAccess; |
| 20 | import com.google.gson.internal.bind.JsonTreeReader; |
| 21 | import java.io.Closeable; |
| 22 | import java.io.EOFException; |
| 23 | import java.io.IOException; |
| 24 | import java.io.Reader; |
| 25 | |
| 26 | /** |
| 27 | * Reads a JSON (<a href="http://www.ietf.org/rfc/rfc4627.txt">RFC 4627</a>) |
| 28 | * encoded value as a stream of tokens. This stream includes both literal |
| 29 | * values (strings, numbers, booleans, and nulls) as well as the begin and |
| 30 | * end delimiters of objects and arrays. The tokens are traversed in |
| 31 | * depth-first order, the same order that they appear in the JSON document. |
| 32 | * Within JSON objects, name/value pairs are represented by a single token. |
| 33 | * |
| 34 | * <h3>Parsing JSON</h3> |
| 35 | * To create a recursive descent parser for your own JSON streams, first create |
| 36 | * an entry point method that creates a {@code JsonReader}. |
| 37 | * |
| 38 | * <p>Next, create handler methods for each structure in your JSON text. You'll |
| 39 | * need a method for each object type and for each array type. |
| 40 | * <ul> |
| 41 | * <li>Within <strong>array handling</strong> methods, first call {@link |
| 42 | * #beginArray} to consume the array's opening bracket. Then create a |
| 43 | * while loop that accumulates values, terminating when {@link #hasNext} |
| 44 | * is false. Finally, read the array's closing bracket by calling {@link |
| 45 | * #endArray}. |
| 46 | * <li>Within <strong>object handling</strong> methods, first call {@link |
| 47 | * #beginObject} to consume the object's opening brace. Then create a |
| 48 | * while loop that assigns values to local variables based on their name. |
| 49 | * This loop should terminate when {@link #hasNext} is false. Finally, |
| 50 | * read the object's closing brace by calling {@link #endObject}. |
| 51 | * </ul> |
| 52 | * <p>When a nested object or array is encountered, delegate to the |
| 53 | * corresponding handler method. |
| 54 | * |
| 55 | * <p>When an unknown name is encountered, strict parsers should fail with an |
| 56 | * exception. Lenient parsers should call {@link #skipValue()} to recursively |
| 57 | * skip the value's nested tokens, which may otherwise conflict. |
| 58 | * |
| 59 | * <p>If a value may be null, you should first check using {@link #peek()}. |
| 60 | * Null literals can be consumed using either {@link #nextNull()} or {@link |
| 61 | * #skipValue()}. |
| 62 | * |
| 63 | * <h3>Example</h3> |
| 64 | * Suppose we'd like to parse a stream of messages such as the following: <pre> {@code |
| 65 | * [ |
| 66 | * { |
| 67 | * "id": 912345678901, |
| 68 | * "text": "How do I read a JSON stream in Java?", |
| 69 | * "geo": null, |
| 70 | * "user": { |
| 71 | * "name": "json_newb", |
| 72 | * "followers_count": 41 |
| 73 | * } |
| 74 | * }, |
| 75 | * { |
| 76 | * "id": 912345678902, |
| 77 | * "text": "@json_newb just use JsonReader!", |
| 78 | * "geo": [50.454722, -104.606667], |
| 79 | * "user": { |
| 80 | * "name": "jesse", |
| 81 | * "followers_count": 2 |
| 82 | * } |
| 83 | * } |
| 84 | * ]}</pre> |
| 85 | * This code implements the parser for the above structure: <pre> {@code |
| 86 | * |
| 87 | * public List<Message> readJsonStream(InputStream in) throws IOException { |
| 88 | * JsonReader reader = new JsonReader(new InputStreamReader(in, "UTF-8")); |
| 89 | * try { |
| 90 | * return readMessagesArray(reader); |
| 91 | * } finally { |
| 92 | * reader.close(); |
| 93 | * } |
| 94 | * } |
| 95 | * |
| 96 | * public List<Message> readMessagesArray(JsonReader reader) throws IOException { |
| 97 | * List<Message> messages = new ArrayList<Message>(); |
| 98 | * |
| 99 | * reader.beginArray(); |
| 100 | * while (reader.hasNext()) { |
| 101 | * messages.add(readMessage(reader)); |
| 102 | * } |
| 103 | * reader.endArray(); |
| 104 | * return messages; |
| 105 | * } |
| 106 | * |
| 107 | * public Message readMessage(JsonReader reader) throws IOException { |
| 108 | * long id = -1; |
| 109 | * String text = null; |
| 110 | * User user = null; |
| 111 | * List<Double> geo = null; |
| 112 | * |
| 113 | * reader.beginObject(); |
| 114 | * while (reader.hasNext()) { |
| 115 | * String name = reader.nextName(); |
| 116 | * if (name.equals("id")) { |
| 117 | * id = reader.nextLong(); |
| 118 | * } else if (name.equals("text")) { |
| 119 | * text = reader.nextString(); |
| 120 | * } else if (name.equals("geo") && reader.peek() != JsonToken.NULL) { |
| 121 | * geo = readDoublesArray(reader); |
| 122 | * } else if (name.equals("user")) { |
| 123 | * user = readUser(reader); |
| 124 | * } else { |
| 125 | * reader.skipValue(); |
| 126 | * } |
| 127 | * } |
| 128 | * reader.endObject(); |
| 129 | * return new Message(id, text, user, geo); |
| 130 | * } |
| 131 | * |
| 132 | * public List<Double> readDoublesArray(JsonReader reader) throws IOException { |
| 133 | * List<Double> doubles = new ArrayList<Double>(); |
| 134 | * |
| 135 | * reader.beginArray(); |
| 136 | * while (reader.hasNext()) { |
| 137 | * doubles.add(reader.nextDouble()); |
| 138 | * } |
| 139 | * reader.endArray(); |
| 140 | * return doubles; |
| 141 | * } |
| 142 | * |
| 143 | * public User readUser(JsonReader reader) throws IOException { |
| 144 | * String username = null; |
| 145 | * int followersCount = -1; |
| 146 | * |
| 147 | * reader.beginObject(); |
| 148 | * while (reader.hasNext()) { |
| 149 | * String name = reader.nextName(); |
| 150 | * if (name.equals("name")) { |
| 151 | * username = reader.nextString(); |
| 152 | * } else if (name.equals("followers_count")) { |
| 153 | * followersCount = reader.nextInt(); |
| 154 | * } else { |
| 155 | * reader.skipValue(); |
| 156 | * } |
| 157 | * } |
| 158 | * reader.endObject(); |
| 159 | * return new User(username, followersCount); |
| 160 | * }}</pre> |
| 161 | * |
| 162 | * <h3>Number Handling</h3> |
| 163 | * This reader permits numeric values to be read as strings and string values to |
| 164 | * be read as numbers. For example, both elements of the JSON array {@code |
| 165 | * [1, "1"]} may be read using either {@link #nextInt} or {@link #nextString}. |
| 166 | * This behavior is intended to prevent lossy numeric conversions: double is |
| 167 | * JavaScript's only numeric type and very large values like {@code |
| 168 | * 9007199254740993} cannot be represented exactly on that platform. To minimize |
| 169 | * precision loss, extremely large values should be written and read as strings |
| 170 | * in JSON. |
| 171 | * |
| 172 | * <a name="nonexecuteprefix"/><h3>Non-Execute Prefix</h3> |
| 173 | * Web servers that serve private data using JSON may be vulnerable to <a |
| 174 | * href="http://en.wikipedia.org/wiki/JSON#Cross-site_request_forgery">Cross-site |
| 175 | * request forgery</a> attacks. In such an attack, a malicious site gains access |
| 176 | * to a private JSON file by executing it with an HTML {@code <script>} tag. |
| 177 | * |
| 178 | * <p>Prefixing JSON files with <code>")]}'\n"</code> makes them non-executable |
| 179 | * by {@code <script>} tags, disarming the attack. Since the prefix is malformed |
| 180 | * JSON, strict parsing fails when it is encountered. This class permits the |
| 181 | * non-execute prefix when {@link #setLenient(boolean) lenient parsing} is |
| 182 | * enabled. |
| 183 | * |
| 184 | * <p>Each {@code JsonReader} may be used to read a single JSON stream. Instances |
| 185 | * of this class are not thread safe. |
| 186 | * |
| 187 | * @author Jesse Wilson |
| 188 | * @since 1.6 |
| 189 | */ |
| 190 | public class JsonReader implements Closeable { |
| 191 | /** The only non-execute prefix this parser permits */ |
| 192 | private static final char[] NON_EXECUTE_PREFIX = ")]}'\n".toCharArray(); |
| 193 | private static final long MIN_INCOMPLETE_INTEGER = Long.MIN_VALUE / 10; |
| 194 | |
| 195 | private static final int PEEKED_NONE = 0; |
| 196 | private static final int PEEKED_BEGIN_OBJECT = 1; |
| 197 | private static final int PEEKED_END_OBJECT = 2; |
| 198 | private static final int PEEKED_BEGIN_ARRAY = 3; |
| 199 | private static final int PEEKED_END_ARRAY = 4; |
| 200 | private static final int PEEKED_TRUE = 5; |
| 201 | private static final int PEEKED_FALSE = 6; |
| 202 | private static final int PEEKED_NULL = 7; |
| 203 | private static final int PEEKED_SINGLE_QUOTED = 8; |
| 204 | private static final int PEEKED_DOUBLE_QUOTED = 9; |
| 205 | private static final int PEEKED_UNQUOTED = 10; |
| 206 | /** When this is returned, the string value is stored in peekedString. */ |
| 207 | private static final int PEEKED_BUFFERED = 11; |
| 208 | private static final int PEEKED_SINGLE_QUOTED_NAME = 12; |
| 209 | private static final int PEEKED_DOUBLE_QUOTED_NAME = 13; |
| 210 | private static final int PEEKED_UNQUOTED_NAME = 14; |
| 211 | /** When this is returned, the integer value is stored in peekedLong. */ |
| 212 | private static final int PEEKED_LONG = 15; |
| 213 | private static final int PEEKED_NUMBER = 16; |
| 214 | private static final int PEEKED_EOF = 17; |
| 215 | |
| 216 | /* State machine when parsing numbers */ |
| 217 | private static final int NUMBER_CHAR_NONE = 0; |
| 218 | private static final int NUMBER_CHAR_SIGN = 1; |
| 219 | private static final int NUMBER_CHAR_DIGIT = 2; |
| 220 | private static final int NUMBER_CHAR_DECIMAL = 3; |
| 221 | private static final int NUMBER_CHAR_FRACTION_DIGIT = 4; |
| 222 | private static final int NUMBER_CHAR_EXP_E = 5; |
| 223 | private static final int NUMBER_CHAR_EXP_SIGN = 6; |
| 224 | private static final int NUMBER_CHAR_EXP_DIGIT = 7; |
| 225 | |
| 226 | /** The input JSON. */ |
| 227 | private final Reader in; |
| 228 | |
| 229 | /** True to accept non-spec compliant JSON */ |
| 230 | private boolean lenient = false; |
| 231 | |
| 232 | /** |
| 233 | * Use a manual buffer to easily read and unread upcoming characters, and |
| 234 | * also so we can create strings without an intermediate StringBuilder. |
| 235 | * We decode literals directly out of this buffer, so it must be at least as |
| 236 | * long as the longest token that can be reported as a number. |
| 237 | */ |
| 238 | private final char[] buffer = new char[1024]; |
| 239 | private int pos = 0; |
| 240 | private int limit = 0; |
| 241 | |
| 242 | private int lineNumber = 0; |
| 243 | private int lineStart = 0; |
| 244 | |
| 245 | private int peeked = PEEKED_NONE; |
| 246 | |
| 247 | /** |
| 248 | * A peeked value that was composed entirely of digits with an optional |
| 249 | * leading dash. Positive values may not have a leading 0. |
| 250 | */ |
| 251 | private long peekedLong; |
| 252 | |
| 253 | /** |
| 254 | * The number of characters in a peeked number literal. Increment 'pos' by |
| 255 | * this after reading a number. |
| 256 | */ |
| 257 | private int peekedNumberLength; |
| 258 | |
| 259 | /** |
| 260 | * A peeked string that should be parsed on the next double, long or string. |
| 261 | * This is populated before a numeric value is parsed and used if that parsing |
| 262 | * fails. |
| 263 | */ |
| 264 | private String peekedString; |
| 265 | |
| 266 | /* |
| 267 | * The nesting stack. Using a manual array rather than an ArrayList saves 20%. |
| 268 | */ |
| 269 | private int[] stack = new int[32]; |
| 270 | private int stackSize = 0; |
| 271 | { |
| 272 | stack[stackSize++] = JsonScope.EMPTY_DOCUMENT; |
| 273 | } |
| 274 | |
| 275 | /** |
| 276 | * Creates a new instance that reads a JSON-encoded stream from {@code in}. |
| 277 | */ |
| 278 | public JsonReader(Reader in) { |
| 279 | if (in == null) { |
| 280 | throw new NullPointerException("in == null"); |
| 281 | } |
| 282 | this.in = in; |
| 283 | } |
| 284 | |
| 285 | /** |
| 286 | * Configure this parser to be be liberal in what it accepts. By default, |
| 287 | * this parser is strict and only accepts JSON as specified by <a |
| 288 | * href="http://www.ietf.org/rfc/rfc4627.txt">RFC 4627</a>. Setting the |
| 289 | * parser to lenient causes it to ignore the following syntax errors: |
| 290 | * |
| 291 | * <ul> |
| 292 | * <li>Streams that start with the <a href="#nonexecuteprefix">non-execute |
| 293 | * prefix</a>, <code>")]}'\n"</code>. |
| 294 | * <li>Streams that include multiple top-level values. With strict parsing, |
| 295 | * each stream must contain exactly one top-level value. |
| 296 | * <li>Top-level values of any type. With strict parsing, the top-level |
| 297 | * value must be an object or an array. |
| 298 | * <li>Numbers may be {@link Double#isNaN() NaNs} or {@link |
| 299 | * Double#isInfinite() infinities}. |
| 300 | * <li>End of line comments starting with {@code //} or {@code #} and |
| 301 | * ending with a newline character. |
| 302 | * <li>C-style comments starting with {@code /*} and ending with |
| 303 | * {@code *}{@code /}. Such comments may not be nested. |
| 304 | * <li>Names that are unquoted or {@code 'single quoted'}. |
| 305 | * <li>Strings that are unquoted or {@code 'single quoted'}. |
| 306 | * <li>Array elements separated by {@code ;} instead of {@code ,}. |
| 307 | * <li>Unnecessary array separators. These are interpreted as if null |
| 308 | * was the omitted value. |
| 309 | * <li>Names and values separated by {@code =} or {@code =>} instead of |
| 310 | * {@code :}. |
| 311 | * <li>Name/value pairs separated by {@code ;} instead of {@code ,}. |
| 312 | * </ul> |
| 313 | */ |
| 314 | public final void setLenient(boolean lenient) { |
| 315 | this.lenient = lenient; |
| 316 | } |
| 317 | |
| 318 | /** |
| 319 | * Returns true if this parser is liberal in what it accepts. |
| 320 | */ |
| 321 | public final boolean isLenient() { |
| 322 | return lenient; |
| 323 | } |
| 324 | |
| 325 | /** |
| 326 | * Consumes the next token from the JSON stream and asserts that it is the |
| 327 | * beginning of a new array. |
| 328 | */ |
| 329 | public void beginArray() throws IOException { |
| 330 | int p = peeked; |
| 331 | if (p == PEEKED_NONE) { |
| 332 | p = doPeek(); |
| 333 | } |
| 334 | if (p == PEEKED_BEGIN_ARRAY) { |
| 335 | push(JsonScope.EMPTY_ARRAY); |
| 336 | peeked = PEEKED_NONE; |
| 337 | } else { |
| 338 | throw new IllegalStateException("Expected BEGIN_ARRAY but was " + peek() |
| 339 | + " at line " + getLineNumber() + " column " + getColumnNumber()); |
| 340 | } |
| 341 | } |
| 342 | |
| 343 | /** |
| 344 | * Consumes the next token from the JSON stream and asserts that it is the |
| 345 | * end of the current array. |
| 346 | */ |
| 347 | public void endArray() throws IOException { |
| 348 | int p = peeked; |
| 349 | if (p == PEEKED_NONE) { |
| 350 | p = doPeek(); |
| 351 | } |
| 352 | if (p == PEEKED_END_ARRAY) { |
| 353 | stackSize--; |
| 354 | peeked = PEEKED_NONE; |
| 355 | } else { |
| 356 | throw new IllegalStateException("Expected END_ARRAY but was " + peek() |
| 357 | + " at line " + getLineNumber() + " column " + getColumnNumber()); |
| 358 | } |
| 359 | } |
| 360 | |
| 361 | /** |
| 362 | * Consumes the next token from the JSON stream and asserts that it is the |
| 363 | * beginning of a new object. |
| 364 | */ |
| 365 | public void beginObject() throws IOException { |
| 366 | int p = peeked; |
| 367 | if (p == PEEKED_NONE) { |
| 368 | p = doPeek(); |
| 369 | } |
| 370 | if (p == PEEKED_BEGIN_OBJECT) { |
| 371 | push(JsonScope.EMPTY_OBJECT); |
| 372 | peeked = PEEKED_NONE; |
| 373 | } else { |
| 374 | throw new IllegalStateException("Expected BEGIN_OBJECT but was " + peek() |
| 375 | + " at line " + getLineNumber() + " column " + getColumnNumber()); |
| 376 | } |
| 377 | } |
| 378 | |
| 379 | /** |
| 380 | * Consumes the next token from the JSON stream and asserts that it is the |
| 381 | * end of the current object. |
| 382 | */ |
| 383 | public void endObject() throws IOException { |
| 384 | int p = peeked; |
| 385 | if (p == PEEKED_NONE) { |
| 386 | p = doPeek(); |
| 387 | } |
| 388 | if (p == PEEKED_END_OBJECT) { |
| 389 | stackSize--; |
| 390 | peeked = PEEKED_NONE; |
| 391 | } else { |
| 392 | throw new IllegalStateException("Expected END_OBJECT but was " + peek() |
| 393 | + " at line " + getLineNumber() + " column " + getColumnNumber()); |
| 394 | } |
| 395 | } |
| 396 | |
| 397 | /** |
| 398 | * Returns true if the current array or object has another element. |
| 399 | */ |
| 400 | public boolean hasNext() throws IOException { |
| 401 | int p = peeked; |
| 402 | if (p == PEEKED_NONE) { |
| 403 | p = doPeek(); |
| 404 | } |
| 405 | return p != PEEKED_END_OBJECT && p != PEEKED_END_ARRAY; |
| 406 | } |
| 407 | |
| 408 | /** |
| 409 | * Returns the type of the next token without consuming it. |
| 410 | */ |
| 411 | public JsonToken peek() throws IOException { |
| 412 | int p = peeked; |
| 413 | if (p == PEEKED_NONE) { |
| 414 | p = doPeek(); |
| 415 | } |
| 416 | |
| 417 | switch (p) { |
| 418 | case PEEKED_BEGIN_OBJECT: |
| 419 | return JsonToken.BEGIN_OBJECT; |
| 420 | case PEEKED_END_OBJECT: |
| 421 | return JsonToken.END_OBJECT; |
| 422 | case PEEKED_BEGIN_ARRAY: |
| 423 | return JsonToken.BEGIN_ARRAY; |
| 424 | case PEEKED_END_ARRAY: |
| 425 | return JsonToken.END_ARRAY; |
| 426 | case PEEKED_SINGLE_QUOTED_NAME: |
| 427 | case PEEKED_DOUBLE_QUOTED_NAME: |
| 428 | case PEEKED_UNQUOTED_NAME: |
| 429 | return JsonToken.NAME; |
| 430 | case PEEKED_TRUE: |
| 431 | case PEEKED_FALSE: |
| 432 | return JsonToken.BOOLEAN; |
| 433 | case PEEKED_NULL: |
| 434 | return JsonToken.NULL; |
| 435 | case PEEKED_SINGLE_QUOTED: |
| 436 | case PEEKED_DOUBLE_QUOTED: |
| 437 | case PEEKED_UNQUOTED: |
| 438 | case PEEKED_BUFFERED: |
| 439 | return JsonToken.STRING; |
| 440 | case PEEKED_LONG: |
| 441 | case PEEKED_NUMBER: |
| 442 | return JsonToken.NUMBER; |
| 443 | case PEEKED_EOF: |
| 444 | return JsonToken.END_DOCUMENT; |
| 445 | default: |
| 446 | throw new AssertionError(); |
| 447 | } |
| 448 | } |
| 449 | |
| 450 | private int doPeek() throws IOException { |
| 451 | int peekStack = stack[stackSize - 1]; |
| 452 | if (peekStack == JsonScope.EMPTY_ARRAY) { |
| 453 | stack[stackSize - 1] = JsonScope.NONEMPTY_ARRAY; |
| 454 | } else if (peekStack == JsonScope.NONEMPTY_ARRAY) { |
| 455 | // Look for a comma before the next element. |
| 456 | int c = nextNonWhitespace(true); |
| 457 | switch (c) { |
| 458 | case ']': |
| 459 | return peeked = PEEKED_END_ARRAY; |
| 460 | case ';': |
| 461 | checkLenient(); // fall-through |
| 462 | case ',': |
| 463 | break; |
| 464 | default: |
| 465 | throw syntaxError("Unterminated array"); |
| 466 | } |
| 467 | } else if (peekStack == JsonScope.EMPTY_OBJECT || peekStack == JsonScope.NONEMPTY_OBJECT) { |
| 468 | stack[stackSize - 1] = JsonScope.DANGLING_NAME; |
| 469 | // Look for a comma before the next element. |
| 470 | if (peekStack == JsonScope.NONEMPTY_OBJECT) { |
| 471 | int c = nextNonWhitespace(true); |
| 472 | switch (c) { |
| 473 | case '}': |
| 474 | return peeked = PEEKED_END_OBJECT; |
| 475 | case ';': |
| 476 | checkLenient(); // fall-through |
| 477 | case ',': |
| 478 | break; |
| 479 | default: |
| 480 | throw syntaxError("Unterminated object"); |
| 481 | } |
| 482 | } |
| 483 | int c = nextNonWhitespace(true); |
| 484 | switch (c) { |
| 485 | case '"': |
| 486 | return peeked = PEEKED_DOUBLE_QUOTED_NAME; |
| 487 | case '\'': |
| 488 | checkLenient(); |
| 489 | return peeked = PEEKED_SINGLE_QUOTED_NAME; |
| 490 | case '}': |
| 491 | if (peekStack != JsonScope.NONEMPTY_OBJECT) { |
| 492 | return peeked = PEEKED_END_OBJECT; |
| 493 | } else { |
| 494 | throw syntaxError("Expected name"); |
| 495 | } |
| 496 | default: |
| 497 | checkLenient(); |
| 498 | pos--; // Don't consume the first character in an unquoted string. |
| 499 | if (isLiteral((char) c)) { |
| 500 | return peeked = PEEKED_UNQUOTED_NAME; |
| 501 | } else { |
| 502 | throw syntaxError("Expected name"); |
| 503 | } |
| 504 | } |
| 505 | } else if (peekStack == JsonScope.DANGLING_NAME) { |
| 506 | stack[stackSize - 1] = JsonScope.NONEMPTY_OBJECT; |
| 507 | // Look for a colon before the value. |
| 508 | int c = nextNonWhitespace(true); |
| 509 | switch (c) { |
| 510 | case ':': |
| 511 | break; |
| 512 | case '=': |
| 513 | checkLenient(); |
| 514 | if ((pos < limit || fillBuffer(1)) && buffer[pos] == '>') { |
| 515 | pos++; |
| 516 | } |
| 517 | break; |
| 518 | default: |
| 519 | throw syntaxError("Expected ':'"); |
| 520 | } |
| 521 | } else if (peekStack == JsonScope.EMPTY_DOCUMENT) { |
| 522 | if (lenient) { |
| 523 | consumeNonExecutePrefix(); |
| 524 | } |
| 525 | stack[stackSize - 1] = JsonScope.NONEMPTY_DOCUMENT; |
| 526 | } else if (peekStack == JsonScope.NONEMPTY_DOCUMENT) { |
| 527 | int c = nextNonWhitespace(false); |
| 528 | if (c == -1) { |
| 529 | return peeked = PEEKED_EOF; |
| 530 | } else { |
| 531 | checkLenient(); |
| 532 | pos--; |
| 533 | } |
| 534 | } else if (peekStack == JsonScope.CLOSED) { |
| 535 | throw new IllegalStateException("JsonReader is closed"); |
| 536 | } |
| 537 | |
| 538 | int c = nextNonWhitespace(true); |
| 539 | switch (c) { |
| 540 | case ']': |
| 541 | if (peekStack == JsonScope.EMPTY_ARRAY) { |
| 542 | return peeked = PEEKED_END_ARRAY; |
| 543 | } |
| 544 | // fall-through to handle ",]" |
| 545 | case ';': |
| 546 | case ',': |
| 547 | // In lenient mode, a 0-length literal in an array means 'null'. |
| 548 | if (peekStack == JsonScope.EMPTY_ARRAY || peekStack == JsonScope.NONEMPTY_ARRAY) { |
| 549 | checkLenient(); |
| 550 | pos--; |
| 551 | return peeked = PEEKED_NULL; |
| 552 | } else { |
| 553 | throw syntaxError("Unexpected value"); |
| 554 | } |
| 555 | case '\'': |
| 556 | checkLenient(); |
| 557 | return peeked = PEEKED_SINGLE_QUOTED; |
| 558 | case '"': |
| 559 | if (stackSize == 1) { |
| 560 | checkLenient(); |
| 561 | } |
| 562 | return peeked = PEEKED_DOUBLE_QUOTED; |
| 563 | case '[': |
| 564 | return peeked = PEEKED_BEGIN_ARRAY; |
| 565 | case '{': |
| 566 | return peeked = PEEKED_BEGIN_OBJECT; |
| 567 | default: |
| 568 | pos--; // Don't consume the first character in a literal value. |
| 569 | } |
| 570 | |
| 571 | if (stackSize == 1) { |
| 572 | checkLenient(); // Top-level value isn't an array or an object. |
| 573 | } |
| 574 | |
| 575 | int result = peekKeyword(); |
| 576 | if (result != PEEKED_NONE) { |
| 577 | return result; |
| 578 | } |
| 579 | |
| 580 | result = peekNumber(); |
| 581 | if (result != PEEKED_NONE) { |
| 582 | return result; |
| 583 | } |
| 584 | |
| 585 | if (!isLiteral(buffer[pos])) { |
| 586 | throw syntaxError("Expected value"); |
| 587 | } |
| 588 | |
| 589 | checkLenient(); |
| 590 | return peeked = PEEKED_UNQUOTED; |
| 591 | } |
| 592 | |
| 593 | private int peekKeyword() throws IOException { |
| 594 | // Figure out which keyword we're matching against by its first character. |
| 595 | char c = buffer[pos]; |
| 596 | String keyword; |
| 597 | String keywordUpper; |
| 598 | int peeking; |
| 599 | if (c == 't' || c == 'T') { |
| 600 | keyword = "true"; |
| 601 | keywordUpper = "TRUE"; |
| 602 | peeking = PEEKED_TRUE; |
| 603 | } else if (c == 'f' || c == 'F') { |
| 604 | keyword = "false"; |
| 605 | keywordUpper = "FALSE"; |
| 606 | peeking = PEEKED_FALSE; |
| 607 | } else if (c == 'n' || c == 'N') { |
| 608 | keyword = "null"; |
| 609 | keywordUpper = "NULL"; |
| 610 | peeking = PEEKED_NULL; |
| 611 | } else { |
| 612 | return PEEKED_NONE; |
| 613 | } |
| 614 | |
| 615 | // Confirm that chars [1..length) match the keyword. |
| 616 | int length = keyword.length(); |
| 617 | for (int i = 1; i < length; i++) { |
| 618 | if (pos + i >= limit && !fillBuffer(i + 1)) { |
| 619 | return PEEKED_NONE; |
| 620 | } |
| 621 | c = buffer[pos + i]; |
| 622 | if (c != keyword.charAt(i) && c != keywordUpper.charAt(i)) { |
| 623 | return PEEKED_NONE; |
| 624 | } |
| 625 | } |
| 626 | |
| 627 | if ((pos + length < limit || fillBuffer(length + 1)) |
| 628 | && isLiteral(buffer[pos + length])) { |
| 629 | return PEEKED_NONE; // Don't match trues, falsey or nullsoft! |
| 630 | } |
| 631 | |
| 632 | // We've found the keyword followed either by EOF or by a non-literal character. |
| 633 | pos += length; |
| 634 | return peeked = peeking; |
| 635 | } |
| 636 | |
| 637 | private int peekNumber() throws IOException { |
| 638 | // Like nextNonWhitespace, this uses locals 'p' and 'l' to save inner-loop field access. |
| 639 | char[] buffer = this.buffer; |
| 640 | int p = pos; |
| 641 | int l = limit; |
| 642 | |
| 643 | long value = 0; // Negative to accommodate Long.MIN_VALUE more easily. |
| 644 | boolean negative = false; |
| 645 | boolean fitsInLong = true; |
| 646 | int last = NUMBER_CHAR_NONE; |
| 647 | |
| 648 | int i = 0; |
| 649 | |
| 650 | charactersOfNumber: |
| 651 | for (; true; i++) { |
| 652 | if (p + i == l) { |
| 653 | if (i == buffer.length) { |
| 654 | // Though this looks like a well-formed number, it's too long to continue reading. Give up |
| 655 | // and let the application handle this as an unquoted literal. |
| 656 | return PEEKED_NONE; |
| 657 | } |
| 658 | if (!fillBuffer(i + 1)) { |
| 659 | break; |
| 660 | } |
| 661 | p = pos; |
| 662 | l = limit; |
| 663 | } |
| 664 | |
| 665 | char c = buffer[p + i]; |
| 666 | switch (c) { |
| 667 | case '-': |
| 668 | if (last == NUMBER_CHAR_NONE) { |
| 669 | negative = true; |
| 670 | last = NUMBER_CHAR_SIGN; |
| 671 | continue; |
| 672 | } else if (last == NUMBER_CHAR_EXP_E) { |
| 673 | last = NUMBER_CHAR_EXP_SIGN; |
| 674 | continue; |
| 675 | } |
| 676 | return PEEKED_NONE; |
| 677 | |
| 678 | case '+': |
| 679 | if (last == NUMBER_CHAR_EXP_E) { |
| 680 | last = NUMBER_CHAR_EXP_SIGN; |
| 681 | continue; |
| 682 | } |
| 683 | return PEEKED_NONE; |
| 684 | |
| 685 | case 'e': |
| 686 | case 'E': |
| 687 | if (last == NUMBER_CHAR_DIGIT || last == NUMBER_CHAR_FRACTION_DIGIT) { |
| 688 | last = NUMBER_CHAR_EXP_E; |
| 689 | continue; |
| 690 | } |
| 691 | return PEEKED_NONE; |
| 692 | |
| 693 | case '.': |
| 694 | if (last == NUMBER_CHAR_DIGIT) { |
| 695 | last = NUMBER_CHAR_DECIMAL; |
| 696 | continue; |
| 697 | } |
| 698 | return PEEKED_NONE; |
| 699 | |
| 700 | default: |
| 701 | if (c < '0' || c > '9') { |
| 702 | if (!isLiteral(c)) { |
| 703 | break charactersOfNumber; |
| 704 | } |
| 705 | return PEEKED_NONE; |
| 706 | } |
| 707 | if (last == NUMBER_CHAR_SIGN || last == NUMBER_CHAR_NONE) { |
| 708 | value = -(c - '0'); |
| 709 | last = NUMBER_CHAR_DIGIT; |
| 710 | } else if (last == NUMBER_CHAR_DIGIT) { |
| 711 | if (value == 0) { |
| 712 | return PEEKED_NONE; // Leading '0' prefix is not allowed (since it could be octal). |
| 713 | } |
| 714 | long newValue = value * 10 - (c - '0'); |
| 715 | fitsInLong &= value > MIN_INCOMPLETE_INTEGER |
| 716 | || (value == MIN_INCOMPLETE_INTEGER && newValue < value); |
| 717 | value = newValue; |
| 718 | } else if (last == NUMBER_CHAR_DECIMAL) { |
| 719 | last = NUMBER_CHAR_FRACTION_DIGIT; |
| 720 | } else if (last == NUMBER_CHAR_EXP_E || last == NUMBER_CHAR_EXP_SIGN) { |
| 721 | last = NUMBER_CHAR_EXP_DIGIT; |
| 722 | } |
| 723 | } |
| 724 | } |
| 725 | |
| 726 | // We've read a complete number. Decide if it's a PEEKED_LONG or a PEEKED_NUMBER. |
| 727 | if (last == NUMBER_CHAR_DIGIT && fitsInLong && (value != Long.MIN_VALUE || negative)) { |
| 728 | peekedLong = negative ? value : -value; |
| 729 | pos += i; |
| 730 | return peeked = PEEKED_LONG; |
| 731 | } else if (last == NUMBER_CHAR_DIGIT || last == NUMBER_CHAR_FRACTION_DIGIT |
| 732 | || last == NUMBER_CHAR_EXP_DIGIT) { |
| 733 | peekedNumberLength = i; |
| 734 | return peeked = PEEKED_NUMBER; |
| 735 | } else { |
| 736 | return PEEKED_NONE; |
| 737 | } |
| 738 | } |
| 739 | |
| 740 | private boolean isLiteral(char c) throws IOException { |
| 741 | switch (c) { |
| 742 | case '/': |
| 743 | case '\\': |
| 744 | case ';': |
| 745 | case '#': |
| 746 | case '=': |
| 747 | checkLenient(); // fall-through |
| 748 | case '{': |
| 749 | case '}': |
| 750 | case '[': |
| 751 | case ']': |
| 752 | case ':': |
| 753 | case ',': |
| 754 | case ' ': |
| 755 | case '\t': |
| 756 | case '\f': |
| 757 | case '\r': |
| 758 | case '\n': |
| 759 | return false; |
| 760 | default: |
| 761 | return true; |
| 762 | } |
| 763 | } |
| 764 | |
| 765 | /** |
| 766 | * Returns the next token, a {@link com.google.gson.stream.JsonToken#NAME property name}, and |
| 767 | * consumes it. |
| 768 | * |
| 769 | * @throws java.io.IOException if the next token in the stream is not a property |
| 770 | * name. |
| 771 | */ |
| 772 | public String nextName() throws IOException { |
| 773 | int p = peeked; |
| 774 | if (p == PEEKED_NONE) { |
| 775 | p = doPeek(); |
| 776 | } |
| 777 | String result; |
| 778 | if (p == PEEKED_UNQUOTED_NAME) { |
| 779 | result = nextUnquotedValue(); |
| 780 | } else if (p == PEEKED_SINGLE_QUOTED_NAME) { |
| 781 | result = nextQuotedValue('\''); |
| 782 | } else if (p == PEEKED_DOUBLE_QUOTED_NAME) { |
| 783 | result = nextQuotedValue('"'); |
| 784 | } else { |
| 785 | throw new IllegalStateException("Expected a name but was " + peek() |
| 786 | + " at line " + getLineNumber() + " column " + getColumnNumber()); |
| 787 | } |
| 788 | peeked = PEEKED_NONE; |
| 789 | return result; |
| 790 | } |
| 791 | |
| 792 | /** |
| 793 | * Returns the {@link com.google.gson.stream.JsonToken#STRING string} value of the next token, |
| 794 | * consuming it. If the next token is a number, this method will return its |
| 795 | * string form. |
| 796 | * |
| 797 | * @throws IllegalStateException if the next token is not a string or if |
| 798 | * this reader is closed. |
| 799 | */ |
| 800 | public String nextString() throws IOException { |
| 801 | int p = peeked; |
| 802 | if (p == PEEKED_NONE) { |
| 803 | p = doPeek(); |
| 804 | } |
| 805 | String result; |
| 806 | if (p == PEEKED_UNQUOTED) { |
| 807 | result = nextUnquotedValue(); |
| 808 | } else if (p == PEEKED_SINGLE_QUOTED) { |
| 809 | result = nextQuotedValue('\''); |
| 810 | } else if (p == PEEKED_DOUBLE_QUOTED) { |
| 811 | result = nextQuotedValue('"'); |
| 812 | } else if (p == PEEKED_BUFFERED) { |
| 813 | result = peekedString; |
| 814 | peekedString = null; |
| 815 | } else if (p == PEEKED_LONG) { |
| 816 | result = Long.toString(peekedLong); |
| 817 | } else if (p == PEEKED_NUMBER) { |
| 818 | result = new String(buffer, pos, peekedNumberLength); |
| 819 | pos += peekedNumberLength; |
| 820 | } else { |
| 821 | throw new IllegalStateException("Expected a string but was " + peek() |
| 822 | + " at line " + getLineNumber() + " column " + getColumnNumber()); |
| 823 | } |
| 824 | peeked = PEEKED_NONE; |
| 825 | return result; |
| 826 | } |
| 827 | |
| 828 | /** |
| 829 | * Returns the {@link com.google.gson.stream.JsonToken#BOOLEAN boolean} value of the next token, |
| 830 | * consuming it. |
| 831 | * |
| 832 | * @throws IllegalStateException if the next token is not a boolean or if |
| 833 | * this reader is closed. |
| 834 | */ |
| 835 | public boolean nextBoolean() throws IOException { |
| 836 | int p = peeked; |
| 837 | if (p == PEEKED_NONE) { |
| 838 | p = doPeek(); |
| 839 | } |
| 840 | if (p == PEEKED_TRUE) { |
| 841 | peeked = PEEKED_NONE; |
| 842 | return true; |
| 843 | } else if (p == PEEKED_FALSE) { |
| 844 | peeked = PEEKED_NONE; |
| 845 | return false; |
| 846 | } |
| 847 | throw new IllegalStateException("Expected a boolean but was " + peek() |
| 848 | + " at line " + getLineNumber() + " column " + getColumnNumber()); |
| 849 | } |
| 850 | |
| 851 | /** |
| 852 | * Consumes the next token from the JSON stream and asserts that it is a |
| 853 | * literal null. |
| 854 | * |
| 855 | * @throws IllegalStateException if the next token is not null or if this |
| 856 | * reader is closed. |
| 857 | */ |
| 858 | public void nextNull() throws IOException { |
| 859 | int p = peeked; |
| 860 | if (p == PEEKED_NONE) { |
| 861 | p = doPeek(); |
| 862 | } |
| 863 | if (p == PEEKED_NULL) { |
| 864 | peeked = PEEKED_NONE; |
| 865 | } else { |
| 866 | throw new IllegalStateException("Expected null but was " + peek() |
| 867 | + " at line " + getLineNumber() + " column " + getColumnNumber()); |
| 868 | } |
| 869 | } |
| 870 | |
| 871 | /** |
| 872 | * Returns the {@link com.google.gson.stream.JsonToken#NUMBER double} value of the next token, |
| 873 | * consuming it. If the next token is a string, this method will attempt to |
| 874 | * parse it as a double using {@link Double#parseDouble(String)}. |
| 875 | * |
| 876 | * @throws IllegalStateException if the next token is not a literal value. |
| 877 | * @throws NumberFormatException if the next literal value cannot be parsed |
| 878 | * as a double, or is non-finite. |
| 879 | */ |
| 880 | public double nextDouble() throws IOException { |
| 881 | int p = peeked; |
| 882 | if (p == PEEKED_NONE) { |
| 883 | p = doPeek(); |
| 884 | } |
| 885 | |
| 886 | if (p == PEEKED_LONG) { |
| 887 | peeked = PEEKED_NONE; |
| 888 | return (double) peekedLong; |
| 889 | } |
| 890 | |
| 891 | if (p == PEEKED_NUMBER) { |
| 892 | peekedString = new String(buffer, pos, peekedNumberLength); |
| 893 | pos += peekedNumberLength; |
| 894 | } else if (p == PEEKED_SINGLE_QUOTED || p == PEEKED_DOUBLE_QUOTED) { |
| 895 | peekedString = nextQuotedValue(p == PEEKED_SINGLE_QUOTED ? '\'' : '"'); |
| 896 | } else if (p == PEEKED_UNQUOTED) { |
| 897 | peekedString = nextUnquotedValue(); |
| 898 | } else if (p != PEEKED_BUFFERED) { |
| 899 | throw new IllegalStateException("Expected a double but was " + peek() |
| 900 | + " at line " + getLineNumber() + " column " + getColumnNumber()); |
| 901 | } |
| 902 | |
| 903 | peeked = PEEKED_BUFFERED; |
| 904 | double result = Double.parseDouble(peekedString); // don't catch this NumberFormatException. |
| 905 | if (!lenient && (Double.isNaN(result) || Double.isInfinite(result))) { |
| 906 | throw new MalformedJsonException("JSON forbids NaN and infinities: " + result |
| 907 | + " at line " + getLineNumber() + " column " + getColumnNumber()); |
| 908 | } |
| 909 | peekedString = null; |
| 910 | peeked = PEEKED_NONE; |
| 911 | return result; |
| 912 | } |
| 913 | |
| 914 | /** |
| 915 | * Returns the {@link com.google.gson.stream.JsonToken#NUMBER long} value of the next token, |
| 916 | * consuming it. If the next token is a string, this method will attempt to |
| 917 | * parse it as a long. If the next token's numeric value cannot be exactly |
| 918 | * represented by a Java {@code long}, this method throws. |
| 919 | * |
| 920 | * @throws IllegalStateException if the next token is not a literal value. |
| 921 | * @throws NumberFormatException if the next literal value cannot be parsed |
| 922 | * as a number, or exactly represented as a long. |
| 923 | */ |
| 924 | public long nextLong() throws IOException { |
| 925 | int p = peeked; |
| 926 | if (p == PEEKED_NONE) { |
| 927 | p = doPeek(); |
| 928 | } |
| 929 | |
| 930 | if (p == PEEKED_LONG) { |
| 931 | peeked = PEEKED_NONE; |
| 932 | return peekedLong; |
| 933 | } |
| 934 | |
| 935 | if (p == PEEKED_NUMBER) { |
| 936 | peekedString = new String(buffer, pos, peekedNumberLength); |
| 937 | pos += peekedNumberLength; |
| 938 | } else if (p == PEEKED_SINGLE_QUOTED || p == PEEKED_DOUBLE_QUOTED) { |
| 939 | peekedString = nextQuotedValue(p == PEEKED_SINGLE_QUOTED ? '\'' : '"'); |
| 940 | try { |
| 941 | long result = Long.parseLong(peekedString); |
| 942 | peeked = PEEKED_NONE; |
| 943 | return result; |
| 944 | } catch (NumberFormatException ignored) { |
| 945 | // Fall back to parse as a double below. |
| 946 | } |
| 947 | } else { |
| 948 | throw new IllegalStateException("Expected a long but was " + peek() |
| 949 | + " at line " + getLineNumber() + " column " + getColumnNumber()); |
| 950 | } |
| 951 | |
| 952 | peeked = PEEKED_BUFFERED; |
| 953 | double asDouble = Double.parseDouble(peekedString); // don't catch this NumberFormatException. |
| 954 | long result = (long) asDouble; |
| 955 | if (result != asDouble) { // Make sure no precision was lost casting to 'long'. |
| 956 | throw new NumberFormatException("Expected a long but was " + peekedString |
| 957 | + " at line " + getLineNumber() + " column " + getColumnNumber()); |
| 958 | } |
| 959 | peekedString = null; |
| 960 | peeked = PEEKED_NONE; |
| 961 | return result; |
| 962 | } |
| 963 | |
| 964 | /** |
| 965 | * Returns the string up to but not including {@code quote}, unescaping any |
| 966 | * character escape sequences encountered along the way. The opening quote |
| 967 | * should have already been read. This consumes the closing quote, but does |
| 968 | * not include it in the returned string. |
| 969 | * |
| 970 | * @param quote either ' or ". |
| 971 | * @throws NumberFormatException if any unicode escape sequences are |
| 972 | * malformed. |
| 973 | */ |
| 974 | private String nextQuotedValue(char quote) throws IOException { |
| 975 | // Like nextNonWhitespace, this uses locals 'p' and 'l' to save inner-loop field access. |
| 976 | char[] buffer = this.buffer; |
| 977 | StringBuilder builder = new StringBuilder(); |
| 978 | while (true) { |
| 979 | int p = pos; |
| 980 | int l = limit; |
| 981 | /* the index of the first character not yet appended to the builder. */ |
| 982 | int start = p; |
| 983 | while (p < l) { |
| 984 | int c = buffer[p++]; |
| 985 | |
| 986 | if (c == quote) { |
| 987 | pos = p; |
| 988 | builder.append(buffer, start, p - start - 1); |
| 989 | return builder.toString(); |
| 990 | } else if (c == '\\') { |
| 991 | pos = p; |
| 992 | builder.append(buffer, start, p - start - 1); |
| 993 | builder.append(readEscapeCharacter()); |
| 994 | p = pos; |
| 995 | l = limit; |
| 996 | start = p; |
| 997 | } else if (c == '\n') { |
| 998 | lineNumber++; |
| 999 | lineStart = p; |
| 1000 | } |
| 1001 | } |
| 1002 | |
| 1003 | builder.append(buffer, start, p - start); |
| 1004 | pos = p; |
| 1005 | if (!fillBuffer(1)) { |
| 1006 | throw syntaxError("Unterminated string"); |
| 1007 | } |
| 1008 | } |
| 1009 | } |
| 1010 | |
| 1011 | /** |
| 1012 | * Returns an unquoted value as a string. |
| 1013 | */ |
| 1014 | @SuppressWarnings("fallthrough") |
| 1015 | private String nextUnquotedValue() throws IOException { |
| 1016 | StringBuilder builder = null; |
| 1017 | int i = 0; |
| 1018 | |
| 1019 | findNonLiteralCharacter: |
| 1020 | while (true) { |
| 1021 | for (; pos + i < limit; i++) { |
| 1022 | switch (buffer[pos + i]) { |
| 1023 | case '/': |
| 1024 | case '\\': |
| 1025 | case ';': |
| 1026 | case '#': |
| 1027 | case '=': |
| 1028 | checkLenient(); // fall-through |
| 1029 | case '{': |
| 1030 | case '}': |
| 1031 | case '[': |
| 1032 | case ']': |
| 1033 | case ':': |
| 1034 | case ',': |
| 1035 | case ' ': |
| 1036 | case '\t': |
| 1037 | case '\f': |
| 1038 | case '\r': |
| 1039 | case '\n': |
| 1040 | break findNonLiteralCharacter; |
| 1041 | } |
| 1042 | } |
| 1043 | |
| 1044 | // Attempt to load the entire literal into the buffer at once. |
| 1045 | if (i < buffer.length) { |
| 1046 | if (fillBuffer(i + 1)) { |
| 1047 | continue; |
| 1048 | } else { |
| 1049 | break; |
| 1050 | } |
| 1051 | } |
| 1052 | |
| 1053 | // use a StringBuilder when the value is too long. This is too long to be a number! |
| 1054 | if (builder == null) { |
| 1055 | builder = new StringBuilder(); |
| 1056 | } |
| 1057 | builder.append(buffer, pos, i); |
| 1058 | pos += i; |
| 1059 | i = 0; |
| 1060 | if (!fillBuffer(1)) { |
| 1061 | break; |
| 1062 | } |
| 1063 | } |
| 1064 | |
| 1065 | String result; |
| 1066 | if (builder == null) { |
| 1067 | result = new String(buffer, pos, i); |
| 1068 | } else { |
| 1069 | builder.append(buffer, pos, i); |
| 1070 | result = builder.toString(); |
| 1071 | } |
| 1072 | pos += i; |
| 1073 | return result; |
| 1074 | } |
| 1075 | |
| 1076 | private void skipQuotedValue(char quote) throws IOException { |
| 1077 | // Like nextNonWhitespace, this uses locals 'p' and 'l' to save inner-loop field access. |
| 1078 | char[] buffer = this.buffer; |
| 1079 | do { |
| 1080 | int p = pos; |
| 1081 | int l = limit; |
| 1082 | /* the index of the first character not yet appended to the builder. */ |
| 1083 | while (p < l) { |
| 1084 | int c = buffer[p++]; |
| 1085 | if (c == quote) { |
| 1086 | pos = p; |
| 1087 | return; |
| 1088 | } else if (c == '\\') { |
| 1089 | pos = p; |
| 1090 | readEscapeCharacter(); |
| 1091 | p = pos; |
| 1092 | l = limit; |
| 1093 | } else if (c == '\n') { |
| 1094 | lineNumber++; |
| 1095 | lineStart = p; |
| 1096 | } |
| 1097 | } |
| 1098 | pos = p; |
| 1099 | } while (fillBuffer(1)); |
| 1100 | throw syntaxError("Unterminated string"); |
| 1101 | } |
| 1102 | |
| 1103 | private void skipUnquotedValue() throws IOException { |
| 1104 | do { |
| 1105 | int i = 0; |
| 1106 | for (; pos + i < limit; i++) { |
| 1107 | switch (buffer[pos + i]) { |
| 1108 | case '/': |
| 1109 | case '\\': |
| 1110 | case ';': |
| 1111 | case '#': |
| 1112 | case '=': |
| 1113 | checkLenient(); // fall-through |
| 1114 | case '{': |
| 1115 | case '}': |
| 1116 | case '[': |
| 1117 | case ']': |
| 1118 | case ':': |
| 1119 | case ',': |
| 1120 | case ' ': |
| 1121 | case '\t': |
| 1122 | case '\f': |
| 1123 | case '\r': |
| 1124 | case '\n': |
| 1125 | pos += i; |
| 1126 | return; |
| 1127 | } |
| 1128 | } |
| 1129 | pos += i; |
| 1130 | } while (fillBuffer(1)); |
| 1131 | } |
| 1132 | |
| 1133 | /** |
| 1134 | * Returns the {@link com.google.gson.stream.JsonToken#NUMBER int} value of the next token, |
| 1135 | * consuming it. If the next token is a string, this method will attempt to |
| 1136 | * parse it as an int. If the next token's numeric value cannot be exactly |
| 1137 | * represented by a Java {@code int}, this method throws. |
| 1138 | * |
| 1139 | * @throws IllegalStateException if the next token is not a literal value. |
| 1140 | * @throws NumberFormatException if the next literal value cannot be parsed |
| 1141 | * as a number, or exactly represented as an int. |
| 1142 | */ |
| 1143 | public int nextInt() throws IOException { |
| 1144 | int p = peeked; |
| 1145 | if (p == PEEKED_NONE) { |
| 1146 | p = doPeek(); |
| 1147 | } |
| 1148 | |
| 1149 | int result; |
| 1150 | if (p == PEEKED_LONG) { |
| 1151 | result = (int) peekedLong; |
| 1152 | if (peekedLong != result) { // Make sure no precision was lost casting to 'int'. |
| 1153 | throw new NumberFormatException("Expected an int but was " + peekedLong |
| 1154 | + " at line " + getLineNumber() + " column " + getColumnNumber()); |
| 1155 | } |
| 1156 | peeked = PEEKED_NONE; |
| 1157 | return result; |
| 1158 | } |
| 1159 | |
| 1160 | if (p == PEEKED_NUMBER) { |
| 1161 | peekedString = new String(buffer, pos, peekedNumberLength); |
| 1162 | pos += peekedNumberLength; |
| 1163 | } else if (p == PEEKED_SINGLE_QUOTED || p == PEEKED_DOUBLE_QUOTED) { |
| 1164 | peekedString = nextQuotedValue(p == PEEKED_SINGLE_QUOTED ? '\'' : '"'); |
| 1165 | try { |
| 1166 | result = Integer.parseInt(peekedString); |
| 1167 | peeked = PEEKED_NONE; |
| 1168 | return result; |
| 1169 | } catch (NumberFormatException ignored) { |
| 1170 | // Fall back to parse as a double below. |
| 1171 | } |
| 1172 | } else { |
| 1173 | throw new IllegalStateException("Expected an int but was " + peek() |
| 1174 | + " at line " + getLineNumber() + " column " + getColumnNumber()); |
| 1175 | } |
| 1176 | |
| 1177 | peeked = PEEKED_BUFFERED; |
| 1178 | double asDouble = Double.parseDouble(peekedString); // don't catch this NumberFormatException. |
| 1179 | result = (int) asDouble; |
| 1180 | if (result != asDouble) { // Make sure no precision was lost casting to 'int'. |
| 1181 | throw new NumberFormatException("Expected an int but was " + peekedString |
| 1182 | + " at line " + getLineNumber() + " column " + getColumnNumber()); |
| 1183 | } |
| 1184 | peekedString = null; |
| 1185 | peeked = PEEKED_NONE; |
| 1186 | return result; |
| 1187 | } |
| 1188 | |
| 1189 | /** |
| 1190 | * Closes this JSON reader and the underlying {@link java.io.Reader}. |
| 1191 | */ |
| 1192 | public void close() throws IOException { |
| 1193 | peeked = PEEKED_NONE; |
| 1194 | stack[0] = JsonScope.CLOSED; |
| 1195 | stackSize = 1; |
| 1196 | in.close(); |
| 1197 | } |
| 1198 | |
| 1199 | /** |
| 1200 | * Skips the next value recursively. If it is an object or array, all nested |
| 1201 | * elements are skipped. This method is intended for use when the JSON token |
| 1202 | * stream contains unrecognized or unhandled values. |
| 1203 | */ |
| 1204 | public void skipValue() throws IOException { |
| 1205 | int count = 0; |
| 1206 | do { |
| 1207 | int p = peeked; |
| 1208 | if (p == PEEKED_NONE) { |
| 1209 | p = doPeek(); |
| 1210 | } |
| 1211 | |
| 1212 | if (p == PEEKED_BEGIN_ARRAY) { |
| 1213 | push(JsonScope.EMPTY_ARRAY); |
| 1214 | count++; |
| 1215 | } else if (p == PEEKED_BEGIN_OBJECT) { |
| 1216 | push(JsonScope.EMPTY_OBJECT); |
| 1217 | count++; |
| 1218 | } else if (p == PEEKED_END_ARRAY) { |
| 1219 | stackSize--; |
| 1220 | count--; |
| 1221 | } else if (p == PEEKED_END_OBJECT) { |
| 1222 | stackSize--; |
| 1223 | count--; |
| 1224 | } else if (p == PEEKED_UNQUOTED_NAME || p == PEEKED_UNQUOTED) { |
| 1225 | skipUnquotedValue(); |
| 1226 | } else if (p == PEEKED_SINGLE_QUOTED || p == PEEKED_SINGLE_QUOTED_NAME) { |
| 1227 | skipQuotedValue('\''); |
| 1228 | } else if (p == PEEKED_DOUBLE_QUOTED || p == PEEKED_DOUBLE_QUOTED_NAME) { |
| 1229 | skipQuotedValue('"'); |
| 1230 | } else if (p == PEEKED_NUMBER) { |
| 1231 | pos += peekedNumberLength; |
| 1232 | } |
| 1233 | peeked = PEEKED_NONE; |
| 1234 | } while (count != 0); |
| 1235 | } |
| 1236 | |
| 1237 | private void push(int newTop) { |
| 1238 | if (stackSize == stack.length) { |
| 1239 | int[] newStack = new int[stackSize * 2]; |
| 1240 | System.arraycopy(stack, 0, newStack, 0, stackSize); |
| 1241 | stack = newStack; |
| 1242 | } |
| 1243 | stack[stackSize++] = newTop; |
| 1244 | } |
| 1245 | |
| 1246 | /** |
| 1247 | * Returns true once {@code limit - pos >= minimum}. If the data is |
| 1248 | * exhausted before that many characters are available, this returns |
| 1249 | * false. |
| 1250 | */ |
| 1251 | private boolean fillBuffer(int minimum) throws IOException { |
| 1252 | char[] buffer = this.buffer; |
| 1253 | lineStart -= pos; |
| 1254 | if (limit != pos) { |
| 1255 | limit -= pos; |
| 1256 | System.arraycopy(buffer, pos, buffer, 0, limit); |
| 1257 | } else { |
| 1258 | limit = 0; |
| 1259 | } |
| 1260 | |
| 1261 | pos = 0; |
| 1262 | int total; |
| 1263 | while ((total = in.read(buffer, limit, buffer.length - limit)) != -1) { |
| 1264 | limit += total; |
| 1265 | |
| 1266 | // if this is the first read, consume an optional byte order mark (BOM) if it exists |
| 1267 | if (lineNumber == 0 && lineStart == 0 && limit > 0 && buffer[0] == '\ufeff') { |
| 1268 | pos++; |
| 1269 | lineStart++; |
| 1270 | minimum++; |
| 1271 | } |
| 1272 | |
| 1273 | if (limit >= minimum) { |
| 1274 | return true; |
| 1275 | } |
| 1276 | } |
| 1277 | return false; |
| 1278 | } |
| 1279 | |
| 1280 | private int getLineNumber() { |
| 1281 | return lineNumber + 1; |
| 1282 | } |
| 1283 | |
| 1284 | private int getColumnNumber() { |
| 1285 | return pos - lineStart + 1; |
| 1286 | } |
| 1287 | |
| 1288 | /** |
| 1289 | * Returns the next character in the stream that is neither whitespace nor a |
| 1290 | * part of a comment. When this returns, the returned character is always at |
| 1291 | * {@code buffer[pos-1]}; this means the caller can always push back the |
| 1292 | * returned character by decrementing {@code pos}. |
| 1293 | */ |
| 1294 | private int nextNonWhitespace(boolean throwOnEof) throws IOException { |
| 1295 | /* |
| 1296 | * This code uses ugly local variables 'p' and 'l' representing the 'pos' |
| 1297 | * and 'limit' fields respectively. Using locals rather than fields saves |
| 1298 | * a few field reads for each whitespace character in a pretty-printed |
| 1299 | * document, resulting in a 5% speedup. We need to flush 'p' to its field |
| 1300 | * before any (potentially indirect) call to fillBuffer() and reread both |
| 1301 | * 'p' and 'l' after any (potentially indirect) call to the same method. |
| 1302 | */ |
| 1303 | char[] buffer = this.buffer; |
| 1304 | int p = pos; |
| 1305 | int l = limit; |
| 1306 | while (true) { |
| 1307 | if (p == l) { |
| 1308 | pos = p; |
| 1309 | if (!fillBuffer(1)) { |
| 1310 | break; |
| 1311 | } |
| 1312 | p = pos; |
| 1313 | l = limit; |
| 1314 | } |
| 1315 | |
| 1316 | int c = buffer[p++]; |
| 1317 | if (c == '\n') { |
| 1318 | lineNumber++; |
| 1319 | lineStart = p; |
| 1320 | continue; |
| 1321 | } else if (c == ' ' || c == '\r' || c == '\t') { |
| 1322 | continue; |
| 1323 | } |
| 1324 | |
| 1325 | if (c == '/') { |
| 1326 | pos = p; |
| 1327 | if (p == l) { |
| 1328 | pos--; // push back '/' so it's still in the buffer when this method returns |
| 1329 | boolean charsLoaded = fillBuffer(2); |
| 1330 | pos++; // consume the '/' again |
| 1331 | if (!charsLoaded) { |
| 1332 | return c; |
| 1333 | } |
| 1334 | } |
| 1335 | |
| 1336 | checkLenient(); |
| 1337 | char peek = buffer[pos]; |
| 1338 | switch (peek) { |
| 1339 | case '*': |
| 1340 | // skip a /* c-style comment */ |
| 1341 | pos++; |
| 1342 | if (!skipTo("*/")) { |
| 1343 | throw syntaxError("Unterminated comment"); |
| 1344 | } |
| 1345 | p = pos + 2; |
| 1346 | l = limit; |
| 1347 | continue; |
| 1348 | |
| 1349 | case '/': |
| 1350 | // skip a // end-of-line comment |
| 1351 | pos++; |
| 1352 | skipToEndOfLine(); |
| 1353 | p = pos; |
| 1354 | l = limit; |
| 1355 | continue; |
| 1356 | |
| 1357 | default: |
| 1358 | return c; |
| 1359 | } |
| 1360 | } else if (c == '#') { |
| 1361 | pos = p; |
| 1362 | /* |
| 1363 | * Skip a # hash end-of-line comment. The JSON RFC doesn't |
| 1364 | * specify this behaviour, but it's required to parse |
| 1365 | * existing documents. See http://b/2571423. |
| 1366 | */ |
| 1367 | checkLenient(); |
| 1368 | skipToEndOfLine(); |
| 1369 | p = pos; |
| 1370 | l = limit; |
| 1371 | } else { |
| 1372 | pos = p; |
| 1373 | return c; |
| 1374 | } |
| 1375 | } |
| 1376 | if (throwOnEof) { |
| 1377 | throw new EOFException("End of input" |
| 1378 | + " at line " + getLineNumber() + " column " + getColumnNumber()); |
| 1379 | } else { |
| 1380 | return -1; |
| 1381 | } |
| 1382 | } |
| 1383 | |
| 1384 | private void checkLenient() throws IOException { |
| 1385 | if (!lenient) { |
| 1386 | throw syntaxError("Use JsonReader.setLenient(true) to accept malformed JSON"); |
| 1387 | } |
| 1388 | } |
| 1389 | |
| 1390 | /** |
| 1391 | * Advances the position until after the next newline character. If the line |
| 1392 | * is terminated by "\r\n", the '\n' must be consumed as whitespace by the |
| 1393 | * caller. |
| 1394 | */ |
| 1395 | private void skipToEndOfLine() throws IOException { |
| 1396 | while (pos < limit || fillBuffer(1)) { |
| 1397 | char c = buffer[pos++]; |
| 1398 | if (c == '\n') { |
| 1399 | lineNumber++; |
| 1400 | lineStart = pos; |
| 1401 | break; |
| 1402 | } else if (c == '\r') { |
| 1403 | break; |
| 1404 | } |
| 1405 | } |
| 1406 | } |
| 1407 | |
| 1408 | /** |
| 1409 | * @param toFind a string to search for. Must not contain a newline. |
| 1410 | */ |
| 1411 | private boolean skipTo(String toFind) throws IOException { |
| 1412 | outer: |
| 1413 | for (; pos + toFind.length() <= limit || fillBuffer(toFind.length()); pos++) { |
| 1414 | if (buffer[pos] == '\n') { |
| 1415 | lineNumber++; |
| 1416 | lineStart = pos + 1; |
| 1417 | continue; |
| 1418 | } |
| 1419 | for (int c = 0; c < toFind.length(); c++) { |
| 1420 | if (buffer[pos + c] != toFind.charAt(c)) { |
| 1421 | continue outer; |
| 1422 | } |
| 1423 | } |
| 1424 | return true; |
| 1425 | } |
| 1426 | return false; |
| 1427 | } |
| 1428 | |
| 1429 | @Override public String toString() { |
| 1430 | return getClass().getSimpleName() |
| 1431 | + " at line " + getLineNumber() + " column " + getColumnNumber(); |
| 1432 | } |
| 1433 | |
| 1434 | /** |
| 1435 | * Unescapes the character identified by the character or characters that |
| 1436 | * immediately follow a backslash. The backslash '\' should have already |
| 1437 | * been read. This supports both unicode escapes "u000A" and two-character |
| 1438 | * escapes "\n". |
| 1439 | * |
| 1440 | * @throws NumberFormatException if any unicode escape sequences are |
| 1441 | * malformed. |
| 1442 | */ |
| 1443 | private char readEscapeCharacter() throws IOException { |
| 1444 | if (pos == limit && !fillBuffer(1)) { |
| 1445 | throw syntaxError("Unterminated escape sequence"); |
| 1446 | } |
| 1447 | |
| 1448 | char escaped = buffer[pos++]; |
| 1449 | switch (escaped) { |
| 1450 | case 'u': |
| 1451 | if (pos + 4 > limit && !fillBuffer(4)) { |
| 1452 | throw syntaxError("Unterminated escape sequence"); |
| 1453 | } |
| 1454 | // Equivalent to Integer.parseInt(stringPool.get(buffer, pos, 4), 16); |
| 1455 | char result = 0; |
| 1456 | for (int i = pos, end = i + 4; i < end; i++) { |
| 1457 | char c = buffer[i]; |
| 1458 | result <<= 4; |
| 1459 | if (c >= '0' && c <= '9') { |
| 1460 | result += (c - '0'); |
| 1461 | } else if (c >= 'a' && c <= 'f') { |
| 1462 | result += (c - 'a' + 10); |
| 1463 | } else if (c >= 'A' && c <= 'F') { |
| 1464 | result += (c - 'A' + 10); |
| 1465 | } else { |
| 1466 | throw new NumberFormatException("\\u" + new String(buffer, pos, 4)); |
| 1467 | } |
| 1468 | } |
| 1469 | pos += 4; |
| 1470 | return result; |
| 1471 | |
| 1472 | case 't': |
| 1473 | return '\t'; |
| 1474 | |
| 1475 | case 'b': |
| 1476 | return '\b'; |
| 1477 | |
| 1478 | case 'n': |
| 1479 | return '\n'; |
| 1480 | |
| 1481 | case 'r': |
| 1482 | return '\r'; |
| 1483 | |
| 1484 | case 'f': |
| 1485 | return '\f'; |
| 1486 | |
| 1487 | case '\n': |
| 1488 | lineNumber++; |
| 1489 | lineStart = pos; |
| 1490 | // fall-through |
| 1491 | |
| 1492 | case '\'': |
| 1493 | case '"': |
| 1494 | case '\\': |
| 1495 | default: |
| 1496 | return escaped; |
| 1497 | } |
| 1498 | } |
| 1499 | |
| 1500 | /** |
| 1501 | * Throws a new IO exception with the given message and a context snippet |
| 1502 | * with this reader's content. |
| 1503 | */ |
| 1504 | private IOException syntaxError(String message) throws IOException { |
| 1505 | throw new MalformedJsonException(message |
| 1506 | + " at line " + getLineNumber() + " column " + getColumnNumber()); |
| 1507 | } |
| 1508 | |
| 1509 | /** |
| 1510 | * Consumes the non-execute prefix if it exists. |
| 1511 | */ |
| 1512 | private void consumeNonExecutePrefix() throws IOException { |
| 1513 | // fast forward through the leading whitespace |
| 1514 | nextNonWhitespace(true); |
| 1515 | pos--; |
| 1516 | |
| 1517 | if (pos + NON_EXECUTE_PREFIX.length > limit && !fillBuffer(NON_EXECUTE_PREFIX.length)) { |
| 1518 | return; |
| 1519 | } |
| 1520 | |
| 1521 | for (int i = 0; i < NON_EXECUTE_PREFIX.length; i++) { |
| 1522 | if (buffer[pos + i] != NON_EXECUTE_PREFIX[i]) { |
| 1523 | return; // not a security token! |
| 1524 | } |
| 1525 | } |
| 1526 | |
| 1527 | // we consumed a security token! |
| 1528 | pos += NON_EXECUTE_PREFIX.length; |
| 1529 | } |
| 1530 | |
| 1531 | static { |
| 1532 | JsonReaderInternalAccess.INSTANCE = new JsonReaderInternalAccess() { |
| 1533 | @Override public void promoteNameToValue(JsonReader reader) throws IOException { |
| 1534 | if (reader instanceof JsonTreeReader) { |
| 1535 | ((JsonTreeReader)reader).promoteNameToValue(); |
| 1536 | return; |
| 1537 | } |
| 1538 | int p = reader.peeked; |
| 1539 | if (p == PEEKED_NONE) { |
| 1540 | p = reader.doPeek(); |
| 1541 | } |
| 1542 | if (p == PEEKED_DOUBLE_QUOTED_NAME) { |
| 1543 | reader.peeked = PEEKED_DOUBLE_QUOTED; |
| 1544 | } else if (p == PEEKED_SINGLE_QUOTED_NAME) { |
| 1545 | reader.peeked = PEEKED_SINGLE_QUOTED; |
| 1546 | } else if (p == PEEKED_UNQUOTED_NAME) { |
| 1547 | reader.peeked = PEEKED_UNQUOTED; |
| 1548 | } else { |
| 1549 | throw new IllegalStateException("Expected a name but was " + reader.peek() + " " |
| 1550 | + " at line " + reader.getLineNumber() + " column " + reader.getColumnNumber()); |
| 1551 | } |
| 1552 | } |
| 1553 | }; |
| 1554 | } |
| 1555 | } |