编写一个应用程序，可以让用户在窗体网页上输入名称、密码，若名称为caterpillar且密码为123456，则显示一个HTML页面响应并有“登录成功”字样，否则显示“登录失败”字样，并由一个超链接连回窗体网页。注意：不可在地址栏上出现用户输入的名称、密码。

由servlet与html完成

 

 

 

 

 

 

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class HelloServlet
 */
public class HelloServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    @Override
    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        PrintWriter out = response.getWriter();
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        //判断是不是账号和密码
        if("caterpillar".equals(username)&&"123456".equals(password)) {
            response.sendRedirect("success.html");
        }else {
            response.sendRedirect("failure.html");
        }
        
    }

}

接着写表单提交页面

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<form method="post" action="index">
<table>
    <tr>
    <td>用户名：</td>
    <td><input type="text" name="username" value=""></td>
    </tr>
    <tr>
    <td>密码：</td>
    <td><input type="password" name="password" value=""></td>
    </tr>
    <tr>
    <td><input type="submit" value="登录"></td>
    <td></td>
    </tr>
</table>

</form>
</body>
</html>

该表单页面的文件名是index，所以这里注意action=“index”，才可以完成。

继续

写web.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

 xmlns="http://java.sun.com/xml/ns/javaee" 
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>HomeWork2_3</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
      <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
   
  </welcome-file-list>
  <servlet>
    <description></description>
    <display-name>HelloServlet</display-name>
    <servlet-name>HelloServlet</servlet-name>
    <servlet-class>net.wanho.servlet.HelloServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>HelloServlet</servlet-name>
    <url-pattern>/index</url-pattern>
  </servlet-mapping>
</web-app>

 

 最后编写一个success.html文件

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<p>登录成功</p>
</body>
</html>

 

posted @ 2020-02-09 23:39  技术白菜  阅读(26)  评论(0)  编辑  收藏  举报