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 ListfindAll();
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 ListfindAll() {
Connection con = null;
PreparedStatement pstmt = null;
ResultSet rs=null;
Listitems=null;
String sql="select id,item,times from voteitems";
try {
con=getConnection();
items=new ArrayList();
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.
*
* 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.
*
* 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.
*
* 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.
*
* 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();
Listvoteitems = 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();
Listvotes = voteDao.findAll();
%>调查问卷
点调查
你对哪种技术最感兴趣
<%
for(VoteItems v:votes){
%><%=v.getItem() %>
<%
}
%>查看结果
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+"/";
Listvoteitems =
(List)request.getAttribute("voteitems");
%>
My JSP 'vote_result.jsp' starting page<%
for(VoteItems v:voteitems){
%><%} %>
<%=v.getItem() %>
<%=v.getTimes() %>
