使用jsp實現使用者登入
阿新 • • 發佈：2018-11-01
login
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>My JSP </title> </head> <body> <form action="/day1030jsp/02.jsp" method="post" > 使用者名稱：<input type="text" name="username"/><br/> 密碼：<input type="password" name="password"/><br/> <input type="submit" value="登入"/> </form> </body> </html>
Dologin
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <% //獲取前端資料 String username=request.getParameter("username"); String password=request.getParameter("password"); //2.處理業務邏輯 登陸 if("admin".equals(username)&&"123456".equals(password)){ //分發轉向 request.getRequestDispatcher("/success.jsp").forward(request, response); }else{ //失敗 response.sendRedirect(request.getContextPath()+"/01.jsp"); } %>
success.jsp
<body>
登陸成功
<%
String username=request.getParameter("username");
out.write(username);
%>
</body>
更改後
login
<body> <% String msg=(String)request.getAttribute("msg"); if(msg!=null){ out.print(msg); } %> <form action="/day1030jsp/servlet/login" method="post" > 使用者名稱：<input type="text" name="username"/><br/> 密碼：<input type="password" name="password"/><br/> <input type="submit" value="登入"/> </form> </body>
dologin
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//編碼
response.setContentType("text/html;charset=utf-8");
request.setCharacterEncoding("utf-8");
//獲取前端資料
String username=request.getParameter("username");
String password=request.getParameter("password");
//2.處理業務邏輯 登陸
if("admin".equals(username)&&"123456".equals(password)){
//分發轉向
//請求轉發 攜帶資料
//request.getRequestDispatcher("/success.jsp").forward(request, response);
//response.sendRedirect(location) 重定向 路徑 location
request.getSession().setAttribute("username",username); //通過session存入資料
response.sendRedirect(request.getContextPath()+"/success.jsp");
}else{
//失敗
//response.sendRedirect(request.getContextPath()+"/01.jsp");
request.setAttribute("msg", "伺服器繁忙稍後再試");
request.getRequestDispatcher("/01.jsp").forward(request,response);
}
}
success.jsp
<body>
登陸成功
<%
/* String username=request.getParameter("username");
out.write(username); */
String username=(String)request.getSession().getAttribute("username");
out.write(username);
%>
</body>