servlet_牛客博客

form表单，输入数据

<form method="post" <%--enctype="multipart/form-data"--%> action="http://localhost:9999/test6/ser01" >
         昵称：<input type="text" name="username" ><br>
         密码：<input type="password" name="password"><br>
         <button ><a href="index.jsp" >登录</a></button>
         <button ><a href="register.jsp" >注册</a></button>
     </form>

servlet 获取数据，存到session中

package com.lxb.servlet;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.io.PrintWriter;
@WebServlet("/ser01")
public class LoginServlet extends HttpServlet {
 //ctrl+o 重写方法；
 @Override
 protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
 //设置编码格式；
 req.setCharacterEncoding("UTF-8");
 resp.setCharacterEncoding("UTF-8");
 resp.setContentType("text/html; charset=UTF-8");
 resp.setHeader("Content-Type", "text/html; charset=UTF-8");
 //打印到控制台
 System.out.println("你好，servlet");
 //通过流来打印到页面
 resp.getWriter().write("你好，2021");
     resp.getWriter().print("<br />");
 //获取username,password参数
 String username = req.getParameter("username");
 String password = req.getParameter("password");
     System.out.println("姓名:"+username);
     System.out.println("密码:"+password);
     // 将数据存到session中；
     HttpSession sess = req.getSession();
     sess.setAttribute("name",username);
     sess.setAttribute("pas",password);
     //输出简单的HTML，附带信息
     PrintWriter out = resp.getWriter();
     out.println("<HTML>");
     out.println("<BODY>");
     out.print("用户名："+username+"<br />");
     out.print("密码："+password+"<br />");
     out.println("  </BODY>");
     out.println("</HTML>");
     //页面跳转：跳转到用户信息页面(inform.jsp);
      req.getRequestDispatcher("inform.jsp").forward(req, resp);
 }
}

获取session中的数据，输出到页面中

// 获取session中的数据 
<td><%=request.getSession().getAttribute("name")%></td>
<td><%=request.getSession().getAttribute("pas")%></td>