登录功能_前台实现

<script>
   // 登录按钮绑定单机事件
   $(function () {
      $("#btn_sub").click(function () {
         // 发送ajax请求，提交表单数据
         $.post("loginServlet",$("loginForm").serialize(),function (data) {
            if (data.flag){
               //登录成功
               location.href="index.html";
            }else {
               //登录失败
               $("#errorMsg").html(data.errorMsg);
            }
         })
      });
   })

登录功能姓名提示

index.html页面中用户姓名的提示信息功能

<script>
    $(function() {
        $.get("findUserServlet",{},function(data){
            var msg = "欢迎回来,"+data.name;
            $("#span_username").html(msg)
        })
    })

@WebServlet("/findUserServlet")
public class FindUserServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//       从session中获取登录用户
        Object user = req.getSession().getAttribute("user");
//       将user写回客户端
        ObjectMapper mapper = new ObjectMapper();
        resp.setContentType("application/json;charset=utf-8");
        mapper.writeValue(resp.getOutputStream(),user);

    }
}