使用javascript及servlet实现客户端和服务器端的表单验证

来源：互联网发布：三流程序员写ui 编辑：程序博客网时间：2024/05/16 23:56

特点

客户端确认

         – 减少服务器负载
         – 缩短用户等待时间
         – 兼容性难

• 服务器端确认
         – 统一确认
         – 兼容性强

– 服务器负载重

JavaScript实现客户端验证

<html><head><script type="text/javascript">function validate() {var userName = document.getElementById("userName1");var passWord = document.getElementById("passWord1");var repassWord = document.getElementById("repassWord1");if(userName.value == "") {alert("用户名不能不为空");return false;}if(passWord.value.length < 6 || passWord.value.length > 10){alert("密码必须符合规则");return false;}if(repassWord.value.length < 6 || repassWord.value.length > 10){alert("密码必须符合规则");return false;}if(passWord.value != repassWord.value){alert("密码前后不一致");return false;}return true;}</script></head><body><form method="post" onsubmit="return validate()">userName:<input type="text" name="userName" id="userName1"><br>passWord:<input type="password" name="passWord" id="passWord1"><br>re-passWord:<input type="password" name="repassWord" id="repassWord1"><br><input type="submit" value="提交"></form></body></html>

但是客户端验证是不可靠的，如用户直接在浏览器输入栏输入：localhost:8080/temp/login.jsp/servlet?username=123&password=123

服务端验证

    public void doGet(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        String userName = request.getParameter("userName");        String passWord = request.getParameter("passWord");        String repassWord = request.getParameter("repassWord");        List<String> list = new ArrayList<String>();        if ("".equals(userName)) {            list.add("用户名不能不为空");        }        if (passWord.length() < 6 || passWord.length() > 10) {            list.add("密码必须符合规则");        }        if (repassWord.length() < 6 || repassWord.length() > 10) {            list.add("密码必须符合规则");        }        if (passWord != null && repassWord != null                && passWord.equals(repassWord)) {            list.add("密码前后不一致");        }        if(list.isEmpty()){            request.setAttribute("userName", userName);            request.setAttribute("userName", passWord);            request.getRequestDispatcher("失败的的jsp页面");        }else{            request.setAttribute("error", list);        }    }