API接口服务端

<?php
/**
* API接口服务端
*
*
*/
    require 'mysql_class.php';
    header('Content-Type:text/html;charset=utf-8'); 

    $action = $_GET['action'];
    switch ($action) { 

        //注册会员
        case"adduserinfo";
            $username = lib_replace_end_tag(trim($_GET['username']));
            $password2 = lib_replace_end_tag(trim($_GET['userpassword']));
            $password = md5("$password2" . ALL_PS);
            $email = lib_replace_end_tag(trim($_GET['email'])); 

            if ($username == '' || $password2 == '' || $password == '') {
                $res = urlencode("参数有误");
                exit(json_encode($res)); //有空信息
            } 

            $sql = "select username from `member` where username='$username'";
            $query = mysql-query.html target=_blank class=infotextkey>mysql_query()($sql, $conn);
            $count = mysql_num_rows($query); 

            if ($count > 0) {
                exit(json_encode(1)); //返回1表示注册失败
            } else { 

                $addsql = "insert into `member` (username,password,email) values ('$username','$password','$email')";
                mysql_query($addsql);
                exit(json_encode(0)); //返回0表示注册成功
            }
            break;

        //查询用户信息
        case"selectuserinfo";
            $username = lib_replace_end_tag($_GET['username']);
            $sql = "select id,username,nickname,mobile from `member` where username='$username'";
            $query = mysql_query($sql, $conn);
            $row = mysql_fetch_array($query);
            foreach ($row as $key => $v) {
                $res[$key] = urlencode($v);
            }
            exit(json_encode($res));
            break;

        //会员登录
        case"userlogin";
            $username = lib_replace_end_tag($_GET['username']);
            $password2 = lib_replace_end_tag(trim($_GET['userpassword']));
            $password = md5("$password2" . ALL_PS);
            $sqluser = "select id,username,password from `member` where username='" . $username . "' and password='" . $password . "'";
            $queryuser = mysql_query($sqluser);
            $rowuser = mysql_fetch_array($queryuser);
            if ($rowuser && is_array($rowuser) && !emptyempty($rowuser)) {
                if ($rowuser['username'] == $username && $rowuser['password'] == $password) {
                    if ($rowuser['password'] == $password) {
                        $res = urlencode("登录成功");
                        exit(json_encode($res));
                    } else {
                        $res = urlencode("密码错误");
                        exit(json_encode($res));
                    }
                } else {
                    $res = urlencode("用户名不存在");
                    exit(json_encode($res));
                }
            } else {
                $res = urlencode("用户名密码错误");
                exit(json_encode($res));
            }
            /*
             * 0：表示登录成功，1：表示密码错误，2：用户名不存在，3：用户名密码错误
             */
            break; 

        default:
            exit(json_encode(error));
    }
?>