JSON编解码函数的php实现

lanneret_sky

由于开发一个ajax file manager for web开源项目,数据交换使用的json格式，后来发现在低版本的php上运行会有问题，仔细调试发现json_decode和json_encode无 法正常工作，于是查阅资料，发现低版本的php没有实现这两个函数，为了兼容性，我只好自己实现一个php版的json编码解码代码，并保证和 json2.js的一致，测试调试并通过，现在将其公布出来，供有相同需求的同学使用：

1. <?php
   
2. /* * ****************************************************************************
   
3.  * $base: $
   
4.  *
   
5.  * $Author: $
   
6.  *         Berlin Qin
   
7.  *
   
8.  * $History: base.js $
   
9.  * Berlin Qin 2011/5/15 created
   
10.  *
    
11.  * $contacted
    
12.  * webfmt@gmail.com
    
13.  * http://www.webfmt.com
    
14.  *
    
15.  * *************************************************************************** */
    
16. /* ===========================================================================
    
17.  * license
    
18.  *
    
19.  * You may not use this file except in compliance with the License.
     * Software distributed under the License is distributed on an "AS IS" basis,
     *   WITHOUT WARRANTY OF ANY KIND, either express or implied,except that you announce  what to you write.
    
     * The Initial Developer of the Original Code is Berlin Qin.
    Copyright (C) 2000-2050, Berlin Qin., All Rights Reserved.
    
20.  *
    
21.  *************************************************************************/
    
22. 
    
23. function jsonDecode($json)
    
24. {
    
25.     $result = array();
    
26.     try
    
27.     {
    
28.         if (PHP_VERSION_ID > 50300)
    
29.         {
    
30.             $result = (array) json_decode($json);
    
31.         }
    
32.         else
    
33.         {
    
34.             $json = str_replace(array("\\\\", "\\\""), array("&#92;", "&#34;"), $json);
    
35.             $parts = preg_split("@(\"[^\"]*\")|([\[\]\{\},:])|\s@is", $json, -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);
    
36.             foreach ($parts as $index => $part)
    
37.             {
    
38.                 if (strlen($part) == 1)
    
39.                 {
    
40.                     switch ($part)
    
41.                     {
    
42.                         case "[":
    
43.                         case "{":
    
44.                             $parts[$index] = "array(";
    
45.                             break;
    
46.                         case "]":
    
47.                         case "}":
    
48.                             $parts[$index] = ")";
    
49.                             break;
    
50.                         case ":":
    
51.                             $parts[$index] = "=>";
    
52.                             break;
    
53.                         case ",":
    
54.                             break;
    
55.                         default:
    
56.                             break;
    
57.                     }
    
58.                 }
    
59.             }
    
60.             $json = str_replace(array("&#92;", "&#34;", "$"), array("\\\\", "\\\"", "\\$"), implode("", $parts));
    
61.             $result = eval("return $json;");
    
62.         }
    
63.     }
    
64.     catch (Exception $e)
    
65.     {
    
66.         $result = array("error" => $e->getCode());
    
67.     }
    
68.     return $result;
    
69. }
    
70. 
    
71. function valueTostr($val)
    
72. {
    
73.     if (is_string($val))
    
74.     {
    
75.         $val = str_replace('\"', "\\\"", $val);
    
76.         $val = str_replace("\\", "\\\\", $val);
    
77.         $val = str_replace("/", "\\/", $val);
    
78.         $val = str_replace("\t", "\\t", $val);
    
79.         $val = str_replace("\n", "\\n", $val);
    
80.         $val = str_replace("\r", "\\r", $val);
    
81.         $val = str_replace("\b", "\\b", $val);
    
82.         $val = str_replace("\f", "\\f", $val);
    
83.         return '"' . $val . '"';
    
84.     }
    
85.     elseif (is_int($val))
    
86.         return sprintf('%d', $val);
    
87.     elseif (is_float($val))
    
88.         return sprintf('%F', $val);
    
89.     elseif (is_bool($val))
    
90.         return ($val ? 'true' : 'false');
    
91.     else
    
92.         return 'null';
    
93. }
    
94. 
    
95. function jsonEncode($arr)
    
96. {
    
97.     $result = "{}";
    
98.     try
    
99.     {
    
100.         if (PHP_VERSION_ID > 50300)
     
101.         {
     
102.             $result = json_encode($arr);
     
103.         }
     
104.         else
     
105.         {
     
106.             $parts = array();
     
107.             $is_list = false;
     
108.             if (!is_array($arr))
     
109.             {
     
110.                 $arr = (array) $arr;
     
111.             }
     
112.             $end = count($arr) - 1;
     
113.             if (count($arr) > 0)
     
114.             {
     
115.                 if (is_numeric(key($arr)))
     
116.                 {
     
117.                     $result = "[";
     
118.                     for ($i = 0; $i < count($arr); $i++)
     
119.                     {
     
120.                         if (is_array($arr[$i]))
     
121.                         {
     
122.                             $result = $result . jsonEncode($arr[$i]);
     
123.                         }
     
124.                         else
     
125.                         {
     
126.                             $result = $result . valueTostr($arr[$i]);
     
127.                         }
     
128.                         if ($i != $end)
     
129.                         {
     
130.                             $result = $result . ",";
     
131.                         }
     
132.                     }
     
133.                     $result = $result . "]";
     
134.                 }
     
135.                 else
     
136.                 {
     
137.                     $result = "{";
     
138.                     $i = 0;
     
139.                     foreach ($arr as $key => $value)
     
140.                     {
     
141.                         $result = $result . '"' . $key . '":';
     
142.                         if (is_array($value))
     
143.                         {
     
144.                             $result = $result . jsonEncode($value);
     
145.                         }
     
146.                         else
     
147.                         {
     
148.                             $result = $result . valueTostr($value);
     
149.                         }
     
150.                         if ($i != $end)
     
151.                         {
     
152.                             $result = $result . ",";
     
153.                         }
     
154.                         $i++;
     
155.                     }
     
156.                     $result = $result . "}";
     
157.                 }
     
158.             }
     
159.             else
     
160.             {
     
161.                 $result = "[]";
     
162.             }
     
163.         }
     
164.     }
     
165.     catch (Exception $e)
     
166.     {
     
167. 
     
168.     }
     
169.     return $result;
     
170. }
     
171. ?>