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Coverage Report

  1. Project Clover database Tue Jun 16 2026 16:23:44 BST
  2. Package org.json

File JSONTokener.java

 

Coverage histogram

../../img/srcFileCovDistChart5.png
43% of files have more coverage

Code metrics

60
190
21
1
631
374
87
0.46
9.05
21
4.14

Classes

Class Line # Actions
JSONTokener 42 190 87
0.4132841241.3%
 

Contributing tests

This file is covered by 44 tests. .

Source view

1    package org.json;
2   
3    import java.io.BufferedReader;
4    import java.io.IOException;
5    import java.io.InputStream;
6    import java.io.InputStreamReader;
7    import java.io.Reader;
8    import java.io.StringReader;
9   
10    /*
11    Copyright (c) 2002 JSON.org
12   
13    Permission is hereby granted, free of charge, to any person obtaining a copy
14    of this software and associated documentation files (the "Software"), to deal
15    in the Software without restriction, including without limitation the rights
16    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
17    copies of the Software, and to permit persons to whom the Software is
18    furnished to do so, subject to the following conditions:
19   
20    The above copyright notice and this permission notice shall be included in all
21    copies or substantial portions of the Software.
22   
23    The Software shall be used for Good, not Evil.
24   
25    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
26    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
27    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
28    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
29    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
30    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31    SOFTWARE.
32    */
33   
34    /**
35    * A JSONTokener takes a source string and extracts characters and tokens from
36    * it. It is used by the JSONObject and JSONArray constructors to parse JSON
37    * source strings.
38    *
39    * @author JSON.org
40    * @version 2014-05-03
41    */
 
42    public class JSONTokener
43    {
44    /** current read character position on the current line. */
45    private long character;
46   
47    /** flag to indicate if the end of the input has been found. */
48    private boolean eof;
49   
50    /** current read index of the input. */
51    private long index;
52   
53    /** current line of the input. */
54    private long line;
55   
56    /** previous character read from the input. */
57    private char previous;
58   
59    /** Reader for the input. */
60    private final Reader reader;
61   
62    /** flag to indicate that a previous character was requested. */
63    private boolean usePrevious;
64   
65    /** the number of characters read in the previous line. */
66    private long characterPreviousLine;
67   
68    /**
69    * Construct a JSONTokener from a Reader. The caller must close the Reader.
70    *
71    * @param reader
72    * A reader.
73    */
 
74  87 toggle public JSONTokener(Reader reader)
75    {
76  87 this.reader = reader.markSupported() ? reader
77    : new BufferedReader(reader);
78  87 this.eof = false;
79  87 this.usePrevious = false;
80  87 this.previous = 0;
81  87 this.index = 0;
82  87 this.character = 1;
83  87 this.characterPreviousLine = 0;
84  87 this.line = 1;
85    }
86   
87    /**
88    * Construct a JSONTokener from an InputStream. The caller must close the
89    * input stream.
90    *
91    * @param inputStream
92    * The source.
93    */
 
94  0 toggle public JSONTokener(InputStream inputStream)
95    {
96  0 this(new InputStreamReader(inputStream));
97    }
98   
99    /**
100    * Construct a JSONTokener from a string.
101    *
102    * @param s
103    * A source string.
104    */
 
105  87 toggle public JSONTokener(String s)
106    {
107  87 this(new StringReader(s));
108    }
109   
110    /**
111    * Back up one character. This provides a sort of lookahead capability, so
112    * that you can test for a digit or letter before attempting to parse the next
113    * number or identifier.
114    *
115    * @throws JSONException
116    * Thrown if trying to step back more than 1 step or if already at
117    * the start of the string
118    */
 
119  357135 toggle public void back() throws JSONException
120    {
121  357128 if (this.usePrevious || this.index <= 0)
122    {
123  0 throw new JSONException("Stepping back two steps is not supported");
124    }
125  357115 this.decrementIndexes();
126  357040 this.usePrevious = true;
127  357037 this.eof = false;
128    }
129   
130    /**
131    * Decrements the indexes for the {@link #back()} method based on the previous
132    * character read.
133    */
 
134  357083 toggle private void decrementIndexes()
135    {
136  357073 this.index--;
137  357059 if (this.previous == '\r' || this.previous == '\n')
138    {
139  0 this.line--;
140  0 this.character = this.characterPreviousLine;
141    }
142  357046 else if (this.character > 0)
143    {
144  357042 this.character--;
145    }
146    }
147   
148    /**
149    * Get the hex value of a character (base16).
150    *
151    * @param c
152    * A character between '0' and '9' or between 'A' and 'F' or between
153    * 'a' and 'f'.
154    * @return An int between 0 and 15, or -1 if c was not a hex digit.
155    */
 
156  0 toggle public static int dehexchar(char c)
157    {
158  0 if (c >= '0' && c <= '9')
159    {
160  0 return c - '0';
161    }
162  0 if (c >= 'A' && c <= 'F')
163    {
164  0 return c - ('A' - 10);
165    }
166  0 if (c >= 'a' && c <= 'f')
167    {
168  0 return c - ('a' - 10);
169    }
170  0 return -1;
171    }
172   
173    /**
174    * Checks if the end of the input has been reached.
175    *
176    * @return true if at the end of the file and we didn't step back
177    */
 
178  5568 toggle public boolean end()
179    {
180  5568 return this.eof && !this.usePrevious;
181    }
182   
183    /**
184    * Determine if the source string still contains characters that next() can
185    * consume.
186    *
187    * @return true if not yet at the end of the source.
188    * @throws JSONException
189    * thrown if there is an error stepping forward or backward while
190    * checking for more data.
191    */
 
192  0 toggle public boolean more() throws JSONException
193    {
194  0 if (this.usePrevious)
195    {
196  0 return true;
197    }
198  0 try
199    {
200  0 this.reader.mark(1);
201    } catch (IOException e)
202    {
203  0 throw new JSONException("Unable to preserve stream position", e);
204    }
205  0 try
206    {
207    // -1 is EOF, but next() can not consume the null character '\0'
208  0 if (this.reader.read() <= 0)
209    {
210  0 this.eof = true;
211  0 return false;
212    }
213  0 this.reader.reset();
214    } catch (IOException e)
215    {
216  0 throw new JSONException(
217    "Unable to read the next character from the stream", e);
218    }
219  0 return true;
220    }
221   
222    /**
223    * Get the next character in the source string.
224    *
225    * @return The next character, or 0 if past the end of the source string.
226    * @throws JSONException
227    * Thrown if there is an error reading the source string.
228    */
 
229  4501322 toggle public char next() throws JSONException
230    {
231  4501349 int c;
232  4502969 if (this.usePrevious)
233    {
234  357072 this.usePrevious = false;
235  357071 c = this.previous;
236    }
237    else
238    {
239  4145886 try
240    {
241  4145876 c = this.reader.read();
242    } catch (IOException exception)
243    {
244  0 throw new JSONException(exception);
245    }
246    }
247  4501056 if (c <= 0)
248    { // End of stream
249  0 this.eof = true;
250  0 return 0;
251    }
252  4500897 this.incrementIndexes(c);
253  4500841 this.previous = (char) c;
254  4500785 return this.previous;
255    }
256   
257    /**
258    * Increments the internal indexes according to the previous character read
259    * and the character passed as the current character.
260    *
261    * @param c
262    * the current character read.
263    */
 
264  4500781 toggle private void incrementIndexes(int c)
265    {
266  4500827 if (c > 0)
267    {
268  4500768 this.index++;
269  4500684 if (c == '\r')
270    {
271  0 this.line++;
272  0 this.characterPreviousLine = this.character;
273  0 this.character = 0;
274    }
275  4500819 else if (c == '\n')
276    {
277  0 if (this.previous != '\r')
278    {
279  0 this.line++;
280  0 this.characterPreviousLine = this.character;
281    }
282  0 this.character = 0;
283    }
284    else
285    {
286  4500828 this.character++;
287    }
288    }
289    }
290   
291    /**
292    * Consume the next character, and check that it matches a specified
293    * character.
294    *
295    * @param c
296    * The character to match.
297    * @return The character.
298    * @throws JSONException
299    * if the character does not match.
300    */
 
301  0 toggle public char next(char c) throws JSONException
302    {
303  0 char n = this.next();
304  0 if (n != c)
305    {
306  0 if (n > 0)
307    {
308  0 throw this.syntaxError(
309    "Expected '" + c + "' and instead saw '" + n + "'");
310    }
311  0 throw this.syntaxError("Expected '" + c + "' and instead saw ''");
312    }
313  0 return n;
314    }
315   
316    /**
317    * Get the next n characters.
318    *
319    * @param n
320    * The number of characters to take.
321    * @return A string of n characters.
322    * @throws JSONException
323    * Substring bounds error if there are not n characters remaining in
324    * the source string.
325    */
 
326  1392 toggle public String next(int n) throws JSONException
327    {
328  1392 if (n == 0)
329    {
330  0 return "";
331    }
332   
333  1392 char[] chars = new char[n];
334  1392 int pos = 0;
335   
336  6960 while (pos < n)
337    {
338  5568 chars[pos] = this.next();
339  5568 if (this.end())
340    {
341  0 throw this.syntaxError("Substring bounds error");
342    }
343  5568 pos += 1;
344    }
345  1392 return new String(chars);
346    }
347   
348    /**
349    * Get the next char in the string, skipping whitespace.
350    *
351    * @throws JSONException
352    * Thrown if there is an error reading the source string.
353    * @return A character, or 0 if there are no more characters.
354    */
 
355  850117 toggle public char nextClean() throws JSONException
356    {
357  850138 for (;;)
358    {
359  850117 char c = this.next();
360  849831 if (c == 0 || c > ' ')
361    {
362  849892 return c;
363    }
364    }
365    }
366   
367    /**
368    * Return the characters up to the next close quote character. Backslash
369    * processing is done. The formal JSON format does not allow strings in single
370    * quotes, but an implementation is allowed to accept them.
371    *
372    * @param quote
373    * The quoting character, either <code>"</code>&nbsp;<small>(double
374    * quote)</small> or <code>'</code>&nbsp;<small>(single
375    * quote)</small>.
376    * @return A String.
377    * @throws JSONException
378    * Unterminated string.
379    */
 
380  203943 toggle public String nextString(char quote) throws JSONException
381    {
382  203942 char c;
383  203940 StringBuilder sb = new StringBuilder();
384  203947 for (;;)
385    {
386  3487312 c = this.next();
387  3487821 switch (c)
388    {
389  0 case 0:
390  0 case '\n':
391  0 case '\r':
392  0 throw this.syntaxError("Unterminated string");
393  1392 case '\\':
394  1392 c = this.next();
395  1392 switch (c)
396    {
397  0 case 'b':
398  0 sb.append('\b');
399  0 break;
400  0 case 't':
401  0 sb.append('\t');
402  0 break;
403  0 case 'n':
404  0 sb.append('\n');
405  0 break;
406  0 case 'f':
407  0 sb.append('\f');
408  0 break;
409  0 case 'r':
410  0 sb.append('\r');
411  0 break;
412  1392 case 'u':
413  1392 try
414    {
415  1392 sb.append((char) Integer.parseInt(this.next(4), 16));
416    } catch (NumberFormatException e)
417    {
418  0 throw this.syntaxError("Illegal escape.", e);
419    }
420  1392 break;
421  0 case '"':
422  0 case '\'':
423  0 case '\\':
424  0 case '/':
425  0 sb.append(c);
426  0 break;
427  0 default:
428  0 throw this.syntaxError("Illegal escape.");
429    }
430  1392 break;
431  3486473 default:
432  3487187 if (c == quote)
433    {
434  203986 return sb.toString();
435    }
436  3283048 sb.append(c);
437    }
438    }
439    }
440   
441    /**
442    * Get the text up but not including the specified character or the end of
443    * line, whichever comes first.
444    *
445    * @param delimiter
446    * A delimiter character.
447    * @return A string.
448    * @throws JSONException
449    * Thrown if there is an error while searching for the delimiter
450    */
 
451  0 toggle public String nextTo(char delimiter) throws JSONException
452    {
453  0 StringBuilder sb = new StringBuilder();
454  0 for (;;)
455    {
456  0 char c = this.next();
457  0 if (c == delimiter || c == 0 || c == '\n' || c == '\r')
458    {
459  0 if (c != 0)
460    {
461  0 this.back();
462    }
463  0 return sb.toString().trim();
464    }
465  0 sb.append(c);
466    }
467    }
468   
469    /**
470    * Get the text up but not including one of the specified delimiter characters
471    * or the end of line, whichever comes first.
472    *
473    * @param delimiters
474    * A set of delimiter characters.
475    * @return A string, trimmed.
476    * @throws JSONException
477    * Thrown if there is an error while searching for the delimiter
478    */
 
479  0 toggle public String nextTo(String delimiters) throws JSONException
480    {
481  0 char c;
482  0 StringBuilder sb = new StringBuilder();
483  0 for (;;)
484    {
485  0 c = this.next();
486  0 if (delimiters.indexOf(c) >= 0 || c == 0 || c == '\n' || c == '\r')
487    {
488  0 if (c != 0)
489    {
490  0 this.back();
491    }
492  0 return sb.toString().trim();
493    }
494  0 sb.append(c);
495    }
496    }
497   
498    /**
499    * Get the next value. The value can be a Boolean, Double, Integer, JSONArray,
500    * JSONObject, Long, or String, or the JSONObject.NULL object.
501    *
502    * @throws JSONException
503    * If syntax error.
504    *
505    * @return An object.
506    */
 
507  265380 toggle public Object nextValue() throws JSONException
508    {
509  265379 char c = this.nextClean();
510  265340 String string;
511   
512  265340 switch (c)
513    {
514  203946 case '"':
515  0 case '\'':
516  203945 return this.nextString(c);
517  14616 case '{':
518  14616 this.back();
519  14616 return new JSONObject(this);
520  6873 case '[':
521  6873 this.back();
522  6873 return new JSONArray(this);
523    }
524   
525    /*
526    * Handle unquoted text. This could be the values true, false, or
527    * null, or it can be a number. An implementation (such as this one)
528    * is allowed to also accept non-standard forms.
529    *
530    * Accumulate characters until we reach the end of the text or a
531    * formatting character.
532    */
533   
534  39931 StringBuilder sb = new StringBuilder();
535  201048 while (c >= ' ' && ",:]}/\\\"[{;=#".indexOf(c) < 0)
536    {
537  161116 sb.append(c);
538  161113 c = this.next();
539    }
540  39932 this.back();
541   
542  39931 string = sb.toString().trim();
543  39931 if ("".equals(string))
544    {
545  0 throw this.syntaxError("Missing value");
546    }
547  39931 return JSONObject.stringToValue(string);
548    }
549   
550    /**
551    * Skip characters until the next character is the requested character. If the
552    * requested character is not found, no characters are skipped.
553    *
554    * @param to
555    * A character to skip to.
556    * @return The requested character, or zero if the requested character is not
557    * found.
558    * @throws JSONException
559    * Thrown if there is an error while searching for the to character
560    */
 
561  0 toggle public char skipTo(char to) throws JSONException
562    {
563  0 char c;
564  0 try
565    {
566  0 long startIndex = this.index;
567  0 long startCharacter = this.character;
568  0 long startLine = this.line;
569  0 this.reader.mark(1000000);
570  0 do
571    {
572  0 c = this.next();
573  0 if (c == 0)
574    {
575    // in some readers, reset() may throw an exception if
576    // the remaining portion of the input is greater than
577    // the mark size (1,000,000 above).
578  0 this.reader.reset();
579  0 this.index = startIndex;
580  0 this.character = startCharacter;
581  0 this.line = startLine;
582  0 return 0;
583    }
584  0 } while (c != to);
585  0 this.reader.mark(1);
586    } catch (IOException exception)
587    {
588  0 throw new JSONException(exception);
589    }
590  0 this.back();
591  0 return c;
592    }
593   
594    /**
595    * Make a JSONException to signal a syntax error.
596    *
597    * @param message
598    * The error message.
599    * @return A JSONException object, suitable for throwing
600    */
 
601  0 toggle public JSONException syntaxError(String message)
602    {
603  0 return new JSONException(message + this.toString());
604    }
605   
606    /**
607    * Make a JSONException to signal a syntax error.
608    *
609    * @param message
610    * The error message.
611    * @param causedBy
612    * The throwable that caused the error.
613    * @return A JSONException object, suitable for throwing
614    */
 
615  0 toggle public JSONException syntaxError(String message, Throwable causedBy)
616    {
617  0 return new JSONException(message + this.toString(), causedBy);
618    }
619   
620    /**
621    * Make a printable string of this JSONTokener.
622    *
623    * @return " at {index} [character {character} line {line}]"
624    */
 
625  0 toggle @Override
626    public String toString()
627    {
628  0 return " at " + this.index + " [character " + this.character + " line "
629    + this.line + "]";
630    }
631    }
  • Report generated by OpenClover v 4.4.1 on Tue Jun 16 2026 16:31:53 BST using coverage data from Tue Jun 16 2026 16:31:41 BST.
  • OpenClover is free and open-source software.