create table voteitems( id number(8) primary key, item varchar2(50) not null, times number(8) default 0 ); create sequence seq_voteitems; insert into voteitems(id,item) values (seq_voteitems.nextval,'jsp'); insert into voteitems(id,item) values (seq_voteitems.nextval,'asp'); insert into voteitems(id,item) values (seq_voteitems.nextval,'asp.net'); insert into voteitems(id,item) values (seq_voteitems.nextval,'php'); commit;
package com.javaweb.dao.util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class BaseDao {
private static String url = "jdbc:oracle:thin:@localhost:1521:orcl";
private static String driver = "oracle.jdbc.driver.OracleDriver";
private static String user="scott";
private static String pwd = "tiger";
public static Connection getConnection()
throws ClassNotFoundException, SQLException{
Class.forName(driver);
Connection con = DriverManager.getConnection(url,user,pwd);
return con;
}
public static void closeAll(ResultSet rs,Statement stmt,Connection con)
throws SQLException{
if(rs!=null)
rs.close();
if(stmt!=null)
stmt.close();
if(con!=null)
con.close();
}
}
package com.javaweb.dao;
import java.util.List;
import com.javaweb.entity.VoteItems;
public interface VoteItemsDao {
public List<VoteItems> findAll();
public boolean update(int id);
}
package com.javaweb.dao.impl;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import com.javaweb.dao.VoteItemsDao;
import com.javaweb.dao.util.BaseDao;
import com.javaweb.entity.VoteItems;
public class VoteItemsDaoImpl extends BaseDao implements VoteItemsDao {
public static void main(String[] args) {
System.out.println(new VoteItemsDaoImpl().findAll().size());
}
public List<VoteItems> findAll() {
Connection con = null;
PreparedStatement pstmt = null;
ResultSet rs=null;
List<VoteItems> items=null;
String sql="select id,item,times from voteitems";
try {
con=getConnection();
items=new ArrayList<VoteItems>();
pstmt=con.prepareStatement(sql);
rs=pstmt.executeQuery();
while(rs.next()){
VoteItems item=new VoteItems();
item.setId(rs.getInt(1));
item.setItem(rs.getString(2));
item.setTimes(rs.getInt(3));
items.add(item);
}
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}finally{
try {
closeAll(rs, pstmt, con);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return items;
}
public boolean update(int id) {
String sql = "update voteitems set times = times + 1 where id = "+id;
Connection con = null;
PreparedStatement pstmt = null;
int n = -1;
try {
con = getConnection();
pstmt = con.prepareStatement(sql);
n=pstmt.executeUpdate();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
try {
closeAll(null, pstmt, con);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return n>0;
}
}
package com.javaweb.servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.javaweb.dao.VoteItemsDao;
import com.javaweb.dao.impl.VoteItemsDaoImpl;
public class UpdateVoteServlet extends HttpServlet {
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String[] strItems = request.getParameterValues("items");
VoteItemsDao dao = new VoteItemsDaoImpl();
for(String item:strItems){
dao.update(Integer.parseInt(item));
System.out.println(item);
}
//
response.sendRedirect("ShowVoteServlet");
//request.getRequestDispatcher("ShowVoteServlet").forward(request, response);
}
}
package com.javaweb.servlet;
import java.io.IOException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.javaweb.dao.VoteItemsDao;
import com.javaweb.dao.impl.VoteItemsDaoImpl;
import com.javaweb.entity.VoteItems;
public class ShowVoteServlet extends HttpServlet {
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
VoteItemsDao dao = new VoteItemsDaoImpl();
List<VoteItems> voteitems = dao.findAll();
request.setAttribute("voteitems", voteitems);
request.getRequestDispatcher("vote_result.jsp").
forward(request, response);
}
}
前端
<%@ page language="java" contentType="text/html; charset=utf-8"%>
<%@ page import="java.util.*,com.javaweb.entity.*,com.javaweb.dao.*,com.javaweb.dao.impl.*" %>
<%
VoteItemsDao voteDao = new VoteItemsDaoImpl();
List<VoteItems> votes = voteDao.findAll();
%>
<html>
<head>
<title>调查问卷</title>
<style>
.outside{ /* 外层表格 */
background:url(bg1.jpg);
font-size:12px;
padding:0px;
}
.title{ /* 表格标题 */
color:#FFFFFF;
font-weight:bold;
text-align:center;
padding-top:3px;
padding-bottom:0px;
}
.tdoutside{
padding:0px 1px 4px 1px;
}
.inside{ /* 内层表格 */
width:269px;
font-size:12px;
padding:0px;
margin:0px;
}
.tdinside{
padding:7px 0px 7px 10px;
background-color:#FFD455;
}
form{
margin:0px; padding:0px;
}
input{
font-size:12px;
}
a{
color:#000000;
}
</style></head>
<body>
<table class="outside">
<tr><td class="title">点调查</td></tr>
<tr><td class="tdoutside">
<form method="post" action="UpdateVoteServlet">
<table class="inside" cellspacing="0">
<tr>
<td class="tdinside">
你对哪种技术最感兴趣<br>
<%
for(VoteItems v:votes){
%>
<input type="checkbox" name="items" value="<%=v.getId() %>"><%=v.getItem() %><br>
<%
}
%>
<input type="submit" value="提交">
<a href="https://www.ctyun.cn/portal/link.html?target=ShowResultServlet">查看结果</a>
</td>
</tr>
</table>
</form>
</td></tr>
</table>
</body>
</html>
投票系统结果
<%@ page language="java" import="java.util.*,com.javaweb.entity.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
List<VoteItems> voteitems =
(List<VoteItems>)request.getAttribute("voteitems");
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="https://www.ctyun.cn/portal/link.html?target=%26lt%3B%25%3DbasePath%25%26gt%3B">
<title>My JSP 'vote_result.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="https://www.ctyun.cn/portal/link.html?target=styles.css">
-->
</head>
<body>
<table>
<%
for(VoteItems v:voteitems){
%>
<tr>
<td><%=v.getItem() %></td>
<td><%=v.getTimes() %></td>
</tr>
<%} %>
</table>
</body>
</html>