190718-05(实现将变量信息显示在登陆页面){JSP/HTML/Servlet}

JSP +HTML + Servlet 实现将用户名显示在登陆页面

分别创建 login/error.html/success.jsp使用jsp语法编写java代码文件，再通过loginServlet.java文件获取用户输入的数据

login.html

创建登陆界面

 

用户名

 

密 码

验证码

 登录

 

    

error.html

提示密码错误

验证码错误，请重新输入

 

返回按钮

重新登录  

success.jsp

尊敬的会员:<%=request.getAttribute("username")%>，欢迎回来~

loginServlet.java

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

request.setCharacterEncoding("utf-8");

response.setContentType("text/html;charset=utf-8");

String userName = request.getParameter("username"); 

String passWord = request.getParameter("pw"); 

String verifyCode = request.getParameter("verifycode");  

if ("1234".equals(verifyCode)) {    //验证码验证

if ("rosin".equals(userName)&&"123456".equals(passWord)) {     //输入用户名及密码

//将 ("userName","rosin");请求转发到 ("success.jsp") ，实现在html中显示变量

request.setAttribute("userName","rosin");

request.getRequestDispatcher("success.jsp").forward(request, response);

} else {

PrintWriter out = response.getWriter();

out.write("

"+"密码输入错误，请重新输入"+"

"); 

out.write("
"); 

out.write("重新登陆"); 

}

} else {

response.sendRedirect("error.html");

}

}