JSON字符串转换为中文，中文转换为JSON字符串

    /**
     * 中文转换为JSON字符串
     * @param $chinese_str 中文：可以包含中文字母数字
     * @return string
     */
    function json_encode($chinese_str)
    {
        $chinese_str = iconv('UTF-8', 'UCS-2', $chinese_str);
        $len = strlen($chinese_str) - 1;
        $str = '';
        for ($i = 0; $i < $len; $i = $i + 2)
        {
            $c1 = $chinese_str[$i];
            $c2 = $chinese_str[$i + 1];
            $unicode1=ord($c1);
            $unicode2=ord($c2);
            if ($unicode1)
            {    // 两个字节的文字
                $unicode1='\u'.base_convert($unicode1, 10, 16);
                $unicode2=base_convert($unicode2, 10, 16);
                if(in_array($unicode2,array('a','b','c','d','e','f'))){
                    $unicode2='0'.$unicode2;
                }
                $str.=$unicode1.$unicode2;
            }else{
                $str.=$c2;
            }
        }
        return $str;
    }
 
    /**
     * JSON字符串转换为中文
     * @param $json_str JSON字符串
     * @return string
     */
    function json_decode($json_str)
    {
        // 转换编码，将JSON字符串转换成可以浏览的utf-8编码
        $pattern = '/([\w]+)|(\\\u([\w]{4}))/i';
        preg_match_all($pattern, $json_str, $matches);
        $chinese_str = '';
        if (!empty($matches))
        {
            $count=count($matches[0]);
            for ($j = 0; $j < $count; $j++)
            {
                $str = $matches[0][$j];
                if (strpos($str, '\\u') === 0)
                {
                    $code = base_convert(substr($str, 2, 2), 16, 10);
                    $code2 = base_convert(substr($str, 4), 16, 10);
                    $c = chr($code).chr($code2);
                    $c = iconv('UCS-2', 'UTF-8', $c);
                    $chinese_str .= $c;
                }
                else
                {
                    $chinese_str .= $str;
                }
            }
        }
        return $chinese_str;
    }