$result = mysql_query($sql); //查询结果
    $users=array();
        $i=0;
            while($row=mysql_fetch_array($result,MYSQL_ASSOC)){
                $users[$i]=$row;
                $i++;
            }
            echo json_encode(array("result"=>"success",‘data‘=>$users));

<?php

/**
 *  function:输出Json格式
 */
class JSON{
    public function encode($array) {
        $this->arrayRecursive($array, ‘urlencode‘, true);
        $json = json_encode($array);
        return urldecode($json);
    }
    private function arrayRecursive(&$array, $function, $apply_to_keys_also = false)
    {
        static $recursive_counter = 0;
        if (++$recursive_counter > 1000) {
            die(‘possible deep recursion attack‘);
        }
        foreach ($array as $key => $value) {
            if (is_array($value)) {
                $this->arrayRecursive($array[$key], $function, $apply_to_keys_also);
            } else {
                $array[$key] = $function($value);
            }

            if ($apply_to_keys_also && is_string($key)) {
                $new_key = $function($key);
                if ($new_key != $key) {
                    $array[$new_key] = $array[$key];
                    unset($array[$key]);
                }
            }
        }
        $recursive_counter--;
    }
}

//调用
//    $result_arr = Array();
//    $count = 0;
//    while($row=mysql_fetch_array($result1,MYSQL_ASSOC)){
//        array_push($result_arr, $row);
//    }
//    $json = new JSON; $out = $json->encode(array(‘result‘=>$result_arr));
//    echo $out;

PrintWriter pw = response.getWriter();
            pw.print("{\"result\":\"success\",\"json\":" + mapper.writeValueAsString(list) + "}");
            pw.close();

//需要用到 jackson-all—1.7.6.jar包