<?php
Class IPQuery{
    private static $_requestURL = 'http://ip.taobao.com/service/getIpInfo.php';
    public static function getIPInfo($ip){
        $long = ip2long($ip);
        if($long === 0){
            throw new Exception('IP address error', 5);
        }
        $ip=long2ip($long);
        $IPInfo = self::queryIPInfo($ip);
        return self::parseJSON($IPInfo);
    }
    
    private static function queryIPInfo($ip){
        $query = http_build_query(array('ip'=>$ip));
        $ch = curl_init();
        $options = array(
            CURLOPT_URL => sprintf('%s?%s', self::$_requestURL, $query),
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_AUTOREFERER => false,
            CURLOPT_FOLLOWLOCATION => false,
            CURLOPT_HEADER => false,
            CURLOPT_TIMEOUT => 3.0,
        );
        curl_setopt_array($ch, $options);
        $content = curl_exec($ch);
        curl_close($ch);
        return $content;
    }
    
    private static function parseJSON($json){
        $O = json_decode ($json, true);
        if(false === is_null($O)){
            return $O;
        }
        if (version_compare(PHP_VERSION, '5.3.0', '>=')) {
            $errorCode = json_last_error();
            if(isset(self::$_JSONParseError[$errorCode])){
                throw new Exception(self::$_JSONParseError[$errorCode], 5);
            }
        }
        throw new Exception('JSON parse error', 5);
    }
    
    private static $_JSONParseError = array(
        JSON_ERROR_NONE=>'No error has occurred',   
        JSON_ERROR_DEPTH=>'The maximum stack depth has been exceeded',   
        JSON_ERROR_CTRL_CHAR=>'Control character error, possibly incorrectly encoded',   
        JSON_ERROR_STATE_MISMATCH=>'Invalid or malformed JSON',   
        JSON_ERROR_SYNTAX=>'Syntax error',   
        JSON_ERROR_UTF8=>'Malformed UTF-8 characters, possibly incorrectly encoded',
    );
}