PHP实现的json类实例_php技巧

本文实例讲述了PHP实现的json类。分享给大家供大家参考。具体如下：

这里注意json_encode只有(PHP 5 >= 5.2.0, PECL json >= 1.2.0)才有

* @author  Matt Knapp 
* @author  Brett Stimmerman 
* @copyright 2005 Michal Migurski
* @version  CVS: $Id: JSON.php,v 1.31 2006/06/28 05:54:17 migurski Exp $
* @license  http://www.opensource.org/licenses/bsd-license.php
* @link  http://pear.php.net/pepr/pepr-proposal-show.php?id=198
*/
/**
* Marker constant for Services_JSON::decode(), used to flag stack state
*/
define('SERVICES_JSON_SLICE', 1);
/**
* Marker constant for Services_JSON::decode(), used to flag stack state
*/
define('SERVICES_JSON_IN_STR', 2);
/**
* Marker constant for Services_JSON::decode(), used to flag stack state
*/
define('SERVICES_JSON_IN_ARR', 3);
/**
* Marker constant for Services_JSON::decode(), used to flag stack state
*/
define('SERVICES_JSON_IN_OBJ', 4);
/**
* Marker constant for Services_JSON::decode(), used to flag stack state
*/
define('SERVICES_JSON_IN_CMT', 5);
/**
* Behavior switch for Services_JSON::decode()
*/
define('SERVICES_JSON_LOOSE_TYPE', 16);
/**
* Behavior switch for Services_JSON::decode()
*/
define('SERVICES_JSON_SUPPRESS_ERRORS', 32);
/**
* Converts to and from JSON format.
*
* Brief example of use:
*
* 
* // create a new instance of Services_JSON
* $json = new Services_JSON();
*
* // convert a complexe value to JSON notation, and send it to the browser
* $value = array('foo', 'bar', array(1, 2, 'baz'), array(3, array(4)));
* $output = $json->encode($value);
*
* print($output);
* // prints: ["foo","bar",[1,2,"baz"],[3,[4]]]
*
* // accept incoming POST data, assumed to be in JSON notation
* $input = file_get_contents('php://input', 1000000);
* $value = $json->decode($input);
* 
*/
class Services_JSON
{
 /**
 * constructs a new JSON instance
 *
 * @param int  $use object behavior flags; combine with boolean-OR
 *
 *       possible values:
 *       - SERVICES_JSON_LOOSE_TYPE: loose typing.
 *         "{...}" syntax creates associative arrays
 *         instead of objects in decode().
 *       - SERVICES_JSON_SUPPRESS_ERRORS: error suppression.
 *         Values which can't be encoded (e.g. resources)
 *         appear as NULL instead of throwing errors.
 *         By default, a deeply-nested resource will
 *         bubble up with an error, so all return values
 *         from encode() should be checked with isError()
 */
 function Services_JSON($use = 0)
 {
  $this->use = $use;
 }
 /**
 * convert a string from one UTF-16 char to one UTF-8 char
 *
 * Normally should be handled by mb_convert_encoding, but
 * provides a slower PHP-only method for installations
 * that lack the multibye string extension.
 *
 * @param string $utf16 UTF-16 character
 * @return string UTF-8 character
 * @access private
 */
 function utf162utf8($utf16)
 {
  // oh please oh please oh please oh please oh please
  if(function_exists('mb_convert_encoding')) {
   return mb_convert_encoding($utf16, 'UTF-8', 'UTF-16');
  }
  $bytes = (ord($utf16{0}) > 6) & 0x1F))
      . chr(0x80 | ($bytes & 0x3F));
   case (0xFFFF & $bytes) == $bytes:
    // return a 3-byte UTF-8 character
    // see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
    return chr(0xE0 | (($bytes >> 12) & 0x0F))
      . chr(0x80 | (($bytes >> 6) & 0x3F))
      . chr(0x80 | ($bytes & 0x3F));
  }
  // ignoring UTF-32 for now, sorry
  return '';
 }
 /**
 * convert a string from one UTF-8 char to one UTF-16 char
 *
 * Normally should be handled by mb_convert_encoding, but
 * provides a slower PHP-only method for installations
 * that lack the multibye string extension.
 *
 * @param string $utf8 UTF-8 character
 * @return string UTF-16 character
 * @access private
 */
 function utf82utf16($utf8)
 {
  // oh please oh please oh please oh please oh please
  if(function_exists('mb_convert_encoding')) {
   return mb_convert_encoding($utf8, 'UTF-16', 'UTF-8');
  }
  switch(strlen($utf8)) {
   case 1:
    // this case should never be reached, because we are in ASCII range
    // see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
    return $utf8;
   case 2:
    // return a UTF-16 character from a 2-byte UTF-8 char
    // see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
    return chr(0x07 & (ord($utf8{0}) >> 2))
      . chr((0xC0 & (ord($utf8{0}) > 2)))
      . chr((0xC0 & (ord($utf8{1}) = 0x20) && ($ord_var_c utf82utf16($char);
       $ascii .= sprintf('\u%04s', bin2hex($utf16));
       break;
      case (($ord_var_c & 0xF0) == 0xE0):
       // characters U-00000800 - U-0000FFFF, mask 1110XXXX
       // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
       $char = pack('C*', $ord_var_c,
           ord($var{$c + 1}),
           ord($var{$c + 2}));
       $c += 2;
       $utf16 = $this->utf82utf16($char);
       $ascii .= sprintf('\u%04s', bin2hex($utf16));
       break;
      case (($ord_var_c & 0xF8) == 0xF0):
       // characters U-00010000 - U-001FFFFF, mask 11110XXX
       // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
       $char = pack('C*', $ord_var_c,
           ord($var{$c + 1}),
           ord($var{$c + 2}),
           ord($var{$c + 3}));
       $c += 3;
       $utf16 = $this->utf82utf16($char);
       $ascii .= sprintf('\u%04s', bin2hex($utf16));
       break;
      case (($ord_var_c & 0xFC) == 0xF8):
       // characters U-00200000 - U-03FFFFFF, mask 111110XX
       // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
       $char = pack('C*', $ord_var_c,
           ord($var{$c + 1}),
           ord($var{$c + 2}),
           ord($var{$c + 3}),
           ord($var{$c + 4}));
       $c += 4;
       $utf16 = $this->utf82utf16($char);
       $ascii .= sprintf('\u%04s', bin2hex($utf16));
       break;
      case (($ord_var_c & 0xFE) == 0xFC):
       // characters U-04000000 - U-7FFFFFFF, mask 1111110X
       // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
       $char = pack('C*', $ord_var_c,
           ord($var{$c + 1}),
           ord($var{$c + 2}),
           ord($var{$c + 3}),
           ord($var{$c + 4}),
           ord($var{$c + 5}));
       $c += 5;
       $utf16 = $this->utf82utf16($char);
       $ascii .= sprintf('\u%04s', bin2hex($utf16));
       break;
     }
    }
    return '"'.$ascii.'"';
   case 'array':
    /*
    * As per JSON spec if any array key is not an integer
    * we must treat the the whole array as an object. We
    * also try to catch a sparsely populated associative
    * array with numeric keys here because some JS engines
    * will create an array with empty indexes up to
    * max_index which can cause memory issues and because
    * the keys, which may be relevant, will be remapped
    * otherwise.
    *
    * As per the ECMA and JSON specification an object may
    * have any string as a property. Unfortunately due to
    * a hole in the ECMA specification if the key is a
    * ECMA reserved word or starts with a digit the
    * parameter is only accessible using ECMAScript's
    * bracket notation.
    */
    // treat as a JSON object
    if (is_array($var) && count($var) && (array_keys($var) !== range(0, sizeof($var) - 1))) {
     $properties = array_map(array($this, 'name_value'),
           array_keys($var),
           array_values($var));
     foreach($properties as $property) {
      if(Services_JSON::isError($property)) {
       return $property;
      }
     }
     return '{' . join(',', $properties) . '}';
    }
    // treat it like a regular array
    $elements = array_map(array($this, 'encode'), $var);
    foreach($elements as $element) {
     if(Services_JSON::isError($element)) {
      return $element;
     }
    }
    return '[' . join(',', $elements) . ']';
   case 'object':
    $vars = get_object_vars($var);
    $properties = array_map(array($this, 'name_value'),
          array_keys($vars),
          array_values($vars));
    foreach($properties as $property) {
     if(Services_JSON::isError($property)) {
      return $property;
     }
    }
    return '{' . join(',', $properties) . '}';
   default:
    return ($this->use & SERVICES_JSON_SUPPRESS_ERRORS)
     ? 'null'
     : new Services_JSON_Error(gettype($var)." can not be encoded as JSON string");
  }
 }
 /**
 * array-walking function for use in generating JSON-formatted name-value pairs
 *
 * @param string $name name of key to use
 * @param mixed $value reference to an array element to be encoded
 *
 * @return string JSON-formatted name-value pair, like '"name":value'
 * @access private
 */
 function name_value($name, $value)
 {
  $encoded_value = $this->encode($value);
  if(Services_JSON::isError($encoded_value)) {
   return $encoded_value;
  }
  return $this->encode(strval($name)) . ':' . $encoded_value;
 }
 /**
 * reduce a string by removing leading and trailing comments and whitespace
 *
 * @param $str string  string value to strip of comments and whitespace
 *
 * @return string string value stripped of comments and whitespace
 * @access private
 */
 function reduce_string($str)
 {
  $str = preg_replace(array(
    // eliminate single line comments in '// ...' form
    '#^\s*//(.+)$#m',
    // eliminate multi-line comments in '/* ... */' form, at start of string
    '#^\s*/\*(.+)\*/#Us',
    // eliminate multi-line comments in '/* ... */' form, at end of string
    '#/\*(.+)\*/\s*$#Us'
   ), '', $str);
  // eliminate extraneous space
  return trim($str);
 }
 /**
 * decodes a JSON string into appropriate variable
 *
 * @param string $str JSON-formatted string
 *
 * @return mixed number, boolean, string, array, or object
 *     corresponding to given JSON input string.
 *     See argument 1 to Services_JSON() above for object-output behavior.
 *     Note that decode() always returns strings
 *     in ASCII or UTF-8 format!
 * @access public
 */
 function decode($str)
 {
  $str = $this->reduce_string($str);
  switch (strtolower($str)) {
   case 'true':
    return true;
   case 'false':
    return false;
   case 'null':
    return null;
   default:
    $m = array();
    if (is_numeric($str)) {
     // Lookie-loo, it's a number
     // This would work on its own, but I'm trying to be
     // good about returning integers where appropriate:
     // return (float)$str;
     // Return float or int, as appropriate
     return ((float)$str == (integer)$str)
      ? (integer)$str
      : (float)$str;
    } elseif (preg_match('/^("|\').*(\1)$/s', $str, $m) && $m[1] == $m[2]) {
     // STRINGS RETURNED IN UTF-8 FORMAT
     $delim = substr($str, 0, 1);
     $chrs = substr($str, 1, -1);
     $utf8 = '';
     $strlen_chrs = strlen($chrs);
     for ($c = 0; $c utf162utf8($utf16);
        $c += 5;
        break;
       case ($ord_chrs_c >= 0x20) && ($ord_chrs_c use & SERVICES_JSON_LOOSE_TYPE) {
       $stk = array(SERVICES_JSON_IN_OBJ);
       $obj = array();
      } else {
       $stk = array(SERVICES_JSON_IN_OBJ);
       $obj = new stdClass();
      }
     }
     array_push($stk, array('what' => SERVICES_JSON_SLICE,
           'where' => 0,
           'delim' => false));
     $chrs = substr($str, 1, -1);
     $chrs = $this->reduce_string($chrs);
     if ($chrs == '') {
      if (reset($stk) == SERVICES_JSON_IN_ARR) {
       return $arr;
      } else {
       return $obj;
      }
     }
     //print("\nparsing {$chrs}\n");
     $strlen_chrs = strlen($chrs);
     for ($c = 0; $c  SERVICES_JSON_SLICE, 'where' => ($c + 1), 'delim' => false));
       //print("Found split at {$c}: ".substr($chrs, $top['where'], (1 + $c - $top['where']))."\n");
       if (reset($stk) == SERVICES_JSON_IN_ARR) {
        // we are in an array, so just push an element onto the stack
        array_push($arr, $this->decode($slice));
       } elseif (reset($stk) == SERVICES_JSON_IN_OBJ) {
        // we are in an object, so figure
        // out the property name and set an
        // element in an associative array,
        // for now
        $parts = array();
        if (preg_match('/^\s*(["\'].*[^\\\]["\'])\s*:\s*(\S.*),?$/Uis', $slice, $parts)) {
         // "name":value pair
         $key = $this->decode($parts[1]);
         $val = $this->decode($parts[2]);
         if ($this->use & SERVICES_JSON_LOOSE_TYPE) {
          $obj[$key] = $val;
         } else {
          $obj->$key = $val;
         }
        } elseif (preg_match('/^\s*(\w+)\s*:\s*(\S.*),?$/Uis', $slice, $parts)) {
         // name:value pair, where name is unquoted
         $key = $parts[1];
         $val = $this->decode($parts[2]);
         if ($this->use & SERVICES_JSON_LOOSE_TYPE) {
          $obj[$key] = $val;
         } else {
          $obj->$key = $val;
         }
        }
       }
      } elseif ((($chrs{$c} == '"') || ($chrs{$c} == "'")) && ($top['what'] != SERVICES_JSON_IN_STR)) {
       // found a quote, and we are not inside a string
       array_push($stk, array('what' => SERVICES_JSON_IN_STR, 'where' => $c, 'delim' => $chrs{$c}));
       //print("Found start of string at {$c}\n");
      } elseif (($chrs{$c} == $top['delim']) &&
         ($top['what'] == SERVICES_JSON_IN_STR) &&
         ((strlen(substr($chrs, 0, $c)) - strlen(rtrim(substr($chrs, 0, $c), '\\'))) % 2 != 1)) {
       // found a quote, we're in a string, and it's not escaped
       // we know that it's not escaped becase there is _not_ an
       // odd number of backslashes at the end of the string so far
       array_pop($stk);
       //print("Found end of string at {$c}: ".substr($chrs, $top['where'], (1 + 1 + $c - $top['where']))."\n");
      } elseif (($chrs{$c} == '[') &&
         in_array($top['what'], array(SERVICES_JSON_SLICE, SERVICES_JSON_IN_ARR, SERVICES_JSON_IN_OBJ))) {
       // found a left-bracket, and we are in an array, object, or slice
       array_push($stk, array('what' => SERVICES_JSON_IN_ARR, 'where' => $c, 'delim' => false));
       //print("Found start of array at {$c}\n");
      } elseif (($chrs{$c} == ']') && ($top['what'] == SERVICES_JSON_IN_ARR)) {
       // found a right-bracket, and we're in an array
       array_pop($stk);
       //print("Found end of array at {$c}: ".substr($chrs, $top['where'], (1 + $c - $top['where']))."\n");
      } elseif (($chrs{$c} == '{') &&
         in_array($top['what'], array(SERVICES_JSON_SLICE, SERVICES_JSON_IN_ARR, SERVICES_JSON_IN_OBJ))) {
       // found a left-brace, and we are in an array, object, or slice
       array_push($stk, array('what' => SERVICES_JSON_IN_OBJ, 'where' => $c, 'delim' => false));
       //print("Found start of object at {$c}\n");
      } elseif (($chrs{$c} == '}') && ($top['what'] == SERVICES_JSON_IN_OBJ)) {
       // found a right-brace, and we're in an object
       array_pop($stk);
       //print("Found end of object at {$c}: ".substr($chrs, $top['where'], (1 + $c - $top['where']))."\n");
      } elseif (($substr_chrs_c_2 == '/*') &&
         in_array($top['what'], array(SERVICES_JSON_SLICE, SERVICES_JSON_IN_ARR, SERVICES_JSON_IN_OBJ))) {
       // found a comment start, and we are in an array, object, or slice
       array_push($stk, array('what' => SERVICES_JSON_IN_CMT, 'where' => $c, 'delim' => false));
       $c++;
       //print("Found start of comment at {$c}\n");
      } elseif (($substr_chrs_c_2 == '*/') && ($top['what'] == SERVICES_JSON_IN_CMT)) {
       // found a comment end, and we're in one now
       array_pop($stk);
       $c++;
       for ($i = $top['where']; $i 

希望本文所述对大家的php程序设计有所帮助。