前端JSP页面: 实现保存用户名和密码

Cookie

后端Servlet验证：

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.Cookie;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.IOException;

import java.io.PrintWriter;

@WebServlet("/Login3")

public class Login3 extends HttpServlet {

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

doPost(req, resp);

}

@Override

protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

//设置请求的编码

req.setCharacterEncoding("utf-8");

//获取请求中的参数

String name=req.getParameter("name");

String password=req.getParameter("password");

String remember=req.getParameter("remember");

//设置响应的文本信息

resp.setContentType("text/html;charset=UTF-8");

PrintWriter out=resp.getWriter();

//判断用户名和密码是否正确

if(name.equals("Admin")&&password.equals("000000")){

// 新建名为name的Cookie

Cookie nameCookie = new Cookie("name",name);

// 新建名为password的Cookie

Cookie passwordCookie = new Cookie("password", password);

// 判断复选框是否被选中，如果选中则返回on

if (remember.equals("on")) {

// 设置保存Cookie的时间长度，

nameCookie.setMaxAge(60*60*24*7); //7天

passwordCookie.setMaxAge(60*60*24*7);

} else {

// 设置将不保存Cookie

nameCookie.setMaxAge(0);

passwordCookie.setMaxAge(0);

}

// 输出到客户端

resp.addCookie(nameCookie);

resp.addCookie(passwordCookie);

// 登录成功后跳转到success.jsp

req.getRequestDispatcher("success.jsp").forward(req, resp);

}else if (!name.equals("Admin") && password.equals("000000")) {// 如果用户名不正确，密码正确

// 保存错误提示数据

req.setAttribute("error", "用户名不正确");

// 登录失败后将跳转到error.jsp

req.getRequestDispatcher("error.jsp").forward(req, resp);

} else if (name.equals("Admin") && !password.equals("000000")) {// 如果用户名正确，密码不正确

// 保存错误提示数据

req.setAttribute("error", "密码不正确");

// 登录失败后将跳转到error.jsp

req.getRequestDispatcher("error.jsp").forward(req, resp);

} else {// 如果用户名和密码都不正确

// 保存错误提示数据

req.setAttribute("error", "用户名和密码都不正确");

// 登录失败后将跳转到error.jsp

req.getRequestDispatcher("error.jsp").forward(req, resp);

}

}

}