根据文档实现较高要求:编写三个jsp文件,和三个servlet(LoginServlet、LogoutServlet和VoteServlet),并使用echarts实现图表内容,请给出完整的代码
时间: 2024-10-13 08:10:11 浏览: 20
为了满足您的需求,这里会提供一个简化的示例,展示如何基于您提供的要求构建相关的JSP页面和Servlet。请注意,由于安全性和隐私原因,实际开发环境中不应直接存储明文密码。此外,关于ECharts的具体JavaScript代码通常放在.html文件或专门的.js文件里而非JSP中,但考虑到您的具体请求,我们将简化处理方式以适应JSP环境。
### login.jsp (登录表单)
```jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<title>Login Page</title>
</head>
<body>
<form action="<%=request.getContextPath()%>/LoginServlet" method="post">
Username: <input type="text" name="username"><br>
Password: <input type="password" name="password"><br>
<input type="checkbox" name="rememberMe" value="true"> Remember me for 3 days<br>
<input type="submit" value="Submit">
</form>
</body>
</html>
```
### welcome.jsp (欢迎页面,带投票选项)
```jsp
<%@ page import="javax.servlet.http.HttpSession" %>
<%@ page import="java.util.Map" %>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<title>Welcome User</title>
</head>
<body>
Welcome <%= session.getAttribute("username") %><br>
<a href="<%=request.getContextPath()%>/LogoutServlet">Sign out</a><br>
Vote:<br>
<form action="<%=request.getContextPath()%>/VoteServlet" method="post">
<input type="checkbox" name="options" value="Option A"> Option A<br>
<input type="checkbox" name="options" value="Option B"> Option B<br>
<input type="submit" value="Vote">
</form>
<hr/>
<%@ include file="voteResult.jsp" %>
</body>
</html>
```
### voteResult.jsp (投票结果显示)
```jsp
<%
Map<String, Integer> results = (Map<String, Integer>) request.getAttribute("results");
if(results != null){
results.forEach((option, count)->{
int totalVotes = results.values().stream().mapToInt(i -> i).sum();
double rate = ((double)count / totalVotes) * 100;
out.println(option + ": " + String.format("%.2f", rate) + "% <img src='echart.png' width='" + rate + "%' height='20'>");
});
}
%>
```
### LoginServlet.java (认证用户)
```java
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.IOException;
public class LoginServlet extends HttpServlet {
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
// 这里应有更严格的校验逻辑,包括与数据库交互等
String username = req.getParameter("username");
String password = req.getParameter("password");
if ("admin".equals(username) && "admin".equals(password)) { // 示例认证逻辑
HttpSession session = req.getSession();
session.setAttribute("username", username);
// 处理记住我功能
boolean rememberMe = Boolean.parseBoolean(req.getParameter("rememberMe"));
if (rememberMe) {
Cookie userCookie = new Cookie("username", username);
Cookie passCookie = new Cookie("password", password);
userCookie.setMaxAge(259200); // 设置过期时间为三天
passCookie.setMaxAge(259200);
resp.addCookie(userCookie);
resp.addCookie(passCookie);
}
resp.sendRedirect(req.getContextPath() + "/welcome.jsp");
} else {
resp.sendRedirect(req.getContextPath() + "/login.jsp");
}
}
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doPost(req, resp);
}
}
```
### LogoutServlet.java (注销用户)
```java
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.IOException;
public class LogoutServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
HttpSession session = request.getSession(false);
if(session != null){
session.invalidate();
}
response.sendRedirect(request.getContextPath() + "/login.jsp");
}
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
}
```
### VoteServlet.java (处理投票)
```java
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 java.io.IOException;
import java.util.HashMap;
import java.util.Map;
@WebServlet("/VoteServlet")
public class VoteServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Map<String, Integer> votes = new HashMap<>();
String[] options = request.getParameterValues("options");
if(options != null) {
for(String option : options) {
votes.put(option, votes.getOrDefault(option, 0) + 1);
}
}
request.setAttribute("results", votes);
// 此处假设welcome.jsp会包含voteResult.jsp
request.getRequestDispatcher("/welcome.jsp").forward(request, response);
}
}
```
### web.xml (部署描述符)
```xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4"
xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<servlet>
<servlet-name>LoginServlet</servlet-name>
<servlet-class>LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/LoginServlet</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>LogoutServlet</servlet-name>
<servlet-class>LogoutServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LogoutServlet</servlet-name>
<url-pattern>/LogoutServlet</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>VoteServlet</servlet-name>
<servlet-class>VoteServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>VoteServlet</servlet-name>
<url-pattern>/VoteServlet</url-pattern>
</servlet-mapping>
</web-app>
```
请注意,上述示例省略了安全性考虑以及详细的错误处理机制。另外,关于ECharts图表的具体嵌入,一般需要引入ECharts库并在客户端渲染数据,而在JSP中可能不是最佳实践。上述代码片段仅供参考学习用途,生产环境中需进一步完善细节。
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