PHP中json_decode()溢出的问题

原文转自：

http://www.thisbug.com/archives/165

有时候会遇到json_decode()解析的字符串中有个长整型,解析成1.0E....之类的溢出问题.
解决办法根据php的版本不同而不同
PHP5.4以上的可以配置下json_decode(),解析的时候这么写就好
//$de_res为需要解析的值;
json_decode($de_res,true, 512, JSON_BIGINT_AS_STRING);
如果是5.4版本以下的可能要麻烦一些了.需要用到以下这个类.来替代json.
怎么用就不用我说了吧.这个方法如果也对你的情况没用的话,要不就升级php版本,要不就用正则吧.Good_Luck!

class JSON {
    protected $t, $c;
    protected $debug;
    protected $useArrays = false;

    static public function decode($s, $array = false, $debug = false) {
        //return json_decode($s, true, 512, JSON_BIGINT_AS_STRING);
        //return json_decode($s, $array);

        // Version >= 5.4.x will suppoort JSON_BIGINT_AS_STRING parameter.
        if (version_compare(PHP_VERSION, '5.3.99', '>=')) {
            return json_decode($s, $array, 512, JSON_BIGINT_AS_STRING);
        }
        // Not supported JSON_BIGINT_AS_STRING so we will use our class.
        else {
            try {
                $d = new JSON($s);
                $d->useArrays = $array;
                $d->setDebug($debug);
                return $d->parseObject(512);
            } catch (Exception $e) {
                return NULL;
            }
        }
    }

    static public function encode($object) {
        return json_encode($object);
    }

    public function __construct($s) {
        $this->setInput($s);
    }

    public function setInput($s) {
        $vv = array_map(function($a) { return isset($a[1]) ? $a[1] : $a; }, token_get_all('<?php ' . $s));
        $this->t = array_values(array_splice($vv, 1));
        $this->c = 0;
        if ($this->debug) print_r($this->t);
    }

    public function setDebug($debug) {
        $this->debug = $debug;
    }

    protected function getCurrentToken() {
        if ($this->c >= count($this->t)) throw(new Exception("EOF"));
        return $this->t[$this->c];
    }

    protected function nextToken() {
        $this->c++;
    }

    protected function parseString() {
        $ct = $this->getCurrentToken();
        if ($ct[0] != '"') throw(new Exception("JSON: Expecting String but found '" . $ct . "'"));
        $this->nextToken();
        //return stripcslashes(substr($ct, 1, -1));
        return json_decode($ct);
    }

    protected function expectValues($values = array()) {
        $ct = $this->getCurrentToken();
        foreach ($values as $value) if ($ct == $value) {
            $this->nextToken();
            return $ct;
        }
        throw(new Exception("JSON: Expecting [" . implode(', ', array_map(function($a) { return "'{$a}'"; }, $values)) . "]"));
    }

    protected function parseNumber() {
        $ct = $this->getCurrentToken();
        if (!is_numeric($ct)) throw(new Exception("JSON: Expecting a number but found '" . $ct . "'"));
        $this->nextToken();
        if ((string)(int)$ct == (string)$ct) {
            return (int)$ct;
        }
        return $ct;
    }

    protected function parseObject($depth = 512) {
        $ret = NULL;
        if ($depth == -1) throw(new Exception("JSON: Depth too long"));
        $ct = $this->getCurrentToken();
        if ($this->debug) echo "--$ct\n";
        switch ($ct[0]) {
            // Object
            case '{':
                $ret = array();
                $this->nextToken();
                if ($this->getCurrentToken() != '}') {
                    do {
                        $key = $this->parseString();
                        if ($this->debug) echo "---key:$key\n";

                        $this->expectValues(array(':'));

                        $value = $this->parseObject($depth - 1);
                        if ($this->debug) echo "---value:$value\n";

                        $ct = $this->expectValues(array(',', '}'));

                        $ret[$key] = $value;
                    } while ($ct == ',');
                } else {
                    $this->nextToken();
                }
                if (!$this->useArrays) $ret = (object)$ret;
                break;
            // Array
            case '[':
                $ret = array();
                $this->nextToken();
                if ($this->getCurrentToken() != ']') {
                    do {
                        $value = $this->parseObject();
                        if ($this->debug) echo "---value:$value\n";
                        $ct = $this->expectValues(array(',', ']'));
                        $ret[] = $value;
                    } while ($ct == ',');
                } else {
                    $this->nextToken();
                }
                //while ()
                break;
            // String
            case '"':
                $ret = $this->parseString();
                break;
            default:
                if (is_numeric($ct[0])) {
                    $ret = $this->parseNumber();
                } else {
                    switch ($ct) {
                        case "null": $this->nextToken(); return NULL;
                        //case "undefined": $this->nextToken(); return NULL;
                        case "true": $this->nextToken(); return true;
                        case "false": $this->nextToken(); return false;
                        default: throw(new Exception("JSON: Invalid object"));
                    }
                }
                break;
        }
        return $ret;
    }

    static public function unittest() {
        $test = function($expr) {
            $a = JSON::decode($expr);
            $b = json_decode($expr, true);
            var_dump($a === $b);
            if ($a != $b) {
                var_dump($a);
                var_dump($b);
            }
            $a2 = JSON::encode($a);
            $b2 = JSON::encode($b);
            var_dump($a2 === $b2);
            //print_r($a);
            //print_r($b);
        };

        $test2 = function($expr, $b) {
            $a = JSON::decode($expr);
            var_dump($a === $b);
            if ($a != $b) {
                var_dump($a);
                var_dump($b);
            }
            //var_export($a);
        };

        // Empty object.
        $test('{}');

        // Simple object
        $test('{"a":"b"}');

        // Object with comma separated items.
        $test('{"k1":"v1","k2":"v2"}');

        // Simple object with numbers
        $test('{"k1":1,"k2":2}');

        // Simple array with numbers
        $test('[1,2,3,4]');

        $test('"\\u10000"');

        // Array with langbuage's constants.
        $test('[3,false,true,null]');

        // Complex array with subobjects.
        $test('[{},{"a":{"b":1}},3,false,{"test":true}]');

        // Complex array.
        $test2(
            '{"order_id":131608840232655,"buyer":100001738131058,"app":118178464915404,"receiver":100001738131058,"amount":2,"update_time":1292862324,"time_placed":1292862322,"data":"","items":[{"item_id":"0","title":"[Test Mode] Unicorn","description":"[Test Mode] Own your own mythical beast!","image_url":"http:\/\/www.facebook.com\/images\/gifts\/21.png","product_url":"http:\/\/www.facebook.com\/images\/gifts\/21.png","price":2,"data":"{\"product_id\":1}"}],"status":"placed"}',
            array (
                'order_id' => '131608840232655',
                'buyer' => '100001738131058',
                'app' => '118178464915404',
                'receiver' => '100001738131058',
                'amount' => 2,
                'update_time' => 1292862324,
                'time_placed' => 1292862322,
                'data' => '',
                'items' => array (
                    0 => array (
                        'item_id' => '0',
                        'title' => '[Test Mode] Unicorn',
                        'description' => '[Test Mode] Own your own mythical beast!',
                        'image_url' => 'http://www.facebook.com/images/gifts/21.png',
                        'product_url' => 'http://www.facebook.com/images/gifts/21.png',
                        'price' => 2,
                        'data' => '{"product_id":1}',
                    ),
                ),
                'status' => 'placed',
            )
        );
    }

    static public function _unittest() {
        if (basename($_SERVER['PHP_SELF']) == basename(__FILE__)) {
            JSON::unittest();
        }
    }
}

function json_decode_fixed($s, $debug = false) {
    return JSON::decode($s, $debug);
}

JSON::_unittest();