简易版用户登录功能-蒲公英云

简易版用户登录功能

Bertha 。 2023-10-01 16:43 80阅读 0赞

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>用户登录</title>
</head>
<body>
    <form action="loginServlet" method="post">
        姓名: <input type="text" name="uname"> <br>
        密码: <input type="password" name="upwd"> <br>
        <button>登录</button>   <span style="color: red;font-size: 12px"><%=request.getAttribute("msg")%></span>
    </form>
</body>
</html>

index.jsp：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
  <head>
    <title>$Title$</title>
  </head>
  <body>
    <h2>欢迎<%=session.getAttribute("uname")%>登录</h2>
  </body>
</html>

LoginServlet.java

@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //设置客户端的编码格式(防止乱码)
        req.setCharacterEncoding("UTF-8");
        //接受客户端传递的参数
        String uname = req.getParameter("uname");
        String upwd = req.getParameter("upwd");
        //判断参数是否为空
        if (uname == null ||"".equals(uname.trim())) {
            //提示用户信息
            req.setAttribute("msg", "用户姓名不能为空");
            //请求转发跳转到login.jsp
            req.getRequestDispatcher("login.jsp").forward(req, resp);
            return;
        }
        if (upwd == null||"".equals(upwd.trim())) {
            //提示用户信息
            req.setAttribute("msg", "用户密码不能为空");
            //请求转发跳转到login.jsp
            req.getRequestDispatcher("login.jsp").forward(req, resp);
            return;
        }
        //判断账号密码是否正确
        if (!"admin".equals(uname)||!"admin".equals(upwd)) {
            //提示用户信息
            req.setAttribute("msg", "登录失败");
            //请求转发跳转到login.jsp
            req.getRequestDispatcher("login.jsp").forward(req, resp);
            return;
        }
        //登录成功
        //设置登录信息到session
        req.getSession().setAttribute("uname",uname);
        //跳转到index.jsp
        resp.sendRedirect("index.jsp");
    }
}