php 获取json数据

<?php   //从笑话表中得到数据    header("Content-type:text/html;charset=utf-8");     $conn=mysql_connect("localhost","zjwdb_91189","1314loveMM") or die("数据库服务器连接错误".mysql_error());    mysql_select_db("zjwdb_91189",$conn) or die("数据库访问错误".mysql_error());    mysql_query("SET NAMES utf8");//注意编码格式phpmyadmin中设置得为gbk，php中同样set name gbk

     $sql=mysql_query("select userID,content,date from pinglun order by date desc",$conn);       $str="[";

    while( $row=mysql_fetch_row($sql)){

                                   $Array = array("userID"=>$row[0], "content"=>$row[1],"date"=>$row[2]);                                 $Array['content'] = urlencode ( $Array['content'] );                                      $str=$str.urldecode(json_encode( $Array));                     $str=$str.",";

                }     $str= utf8_substr($str,0,-1);      $str=  $str."]";         echo  $str; mysql_free_result($sql); mysql_close($conn);

function utf8_substr($str,$start=0) {

    if(empty($str)){

        return false;

    }

    if (function_exists('mb_substr')){

        if(func_num_args() >= 3) {

            $end = func_get_arg(2);

            return mb_substr($str,$start,$end,'utf-8');

        }

        else {

            mb_internal_encoding("UTF-8");

            return mb_substr($str,$start);

        }      

 

    }

    else {

        $null = "";

        preg_match_all("/./u", $str, $ar);

        if(func_num_args() >= 3) {

            $end = func_get_arg(2);

            return join($null, array_slice($ar[0],$start,$end));

        }

        else {

            return join($null, array_slice($ar[0],$start));

        }

    }

} ?>