votemanagedao.java

这是我们做的一个网上购物系统,包手用户和管理员两大功能模块,采用jsp+servlet+java bean技术.

package com.qyg.shop.vote;

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

import com.qyg.database.DbOperatorHandle;
import com.qyg.shop.sales.Sales;

public class VoteManageDAO implements VoteDAO {

	DbOperatorHandle doh=null;
	public VoteManageDAO() {
		// TODO Auto-generated constructor stub
		doh=new DbOperatorHandle();
	}
	
	public void add(Vote vote) {
		// TODO Auto-generated method stub
		try{
			PreparedStatement ps=doh.getCon().prepareStatement("insert vote values(null,?,null)");
			ps.setInt(1, vote.getVote_class());
			ps.execute();
			ps.close();
		}catch (Exception e) {			
			// TODO: handle exception
			System.out.print("添加vote错误");
			e.printStackTrace();
		}
		finally{
			doh.closeCon();
		}
	}

	public void delete(int vote_id) {
		// TODO Auto-generated method stub
		try{
			Statement st=doh.getCon().createStatement();
			String sql="delete from vote where vote_id="+vote_id;
			System.out.print(sql);
			st.executeUpdate(sql);
			st.close();
		}
		catch (Exception e) {
			// TODO: handle exception
			System.out.println("删除指定投票信息失败");
			e.printStackTrace();
		}
		finally{
			doh.closeCon();
		}
	}
	
	public int getVoteByClass(int vote_class) {
		// TODO Auto-generated method stub
		int total=0;
		try{
			Statement st=doh.getCon().createStatement();
			String sql="select * from vote where vote_class="+vote_class;
			ResultSet rs=st.executeQuery(sql);
			while(rs.next()){
				total++;
			}
		}
		catch (Exception e) {
			// TODO: handle exception
			System.out.println("得到投票总数wrong");
			e.printStackTrace();
		}
		finally{
			doh.closeCon();
		}
		return total;
	}

	public List<Vote> getAllVotes() {
		// TODO Auto-generated method stub
		List<Vote> votes=null;
		try{
			votes=new ArrayList<Vote>();
			Statement st=doh.getCon().createStatement();
			String sql="select * from vote";
			ResultSet rs=st.executeQuery(sql);
			while(rs.next()){
				Vote vote=this.getVoteByRs(rs);
				votes.add(vote);
			}
			rs.close();
			st.close();
		}
		catch (Exception e) {
			// TODO: handle exception
			System.out.println("得到所有消费信息");
			e.printStackTrace();
		}
		finally{
			doh.closeCon();
		}
		return votes;
	}

	public int getTotalVotes() {
		// TODO Auto-generated method stub
		int total=0;
		try{
			Statement st=doh.getCon().createStatement();
			String sql="select count(*) from vote";
			ResultSet rs=st.executeQuery(sql);
			if(rs.next()){
				total=rs.getInt(1);
			}
		}
		catch (Exception e) {
			// TODO: handle exception
			System.out.println("得到投票总数wrong");
			e.printStackTrace();
		}
		finally{
			doh.closeCon();
		}
		return total;
	}

	public Vote getVoteByRs(ResultSet rs) {
		// TODO Auto-generated method stub
		Vote vote=null;
		try{
			vote=new Vote();
			vote.setVote_id(rs.getInt("vote_id"));
			vote.setVote_class(rs.getInt("vote_class"));
			vote.setVote_date(rs.getTimestamp("vote_date"));
		}
		catch (Exception e) {
			// TODO: handle exception
			System.out.print("把rs中的值返回到Sales中");
		}
		return vote;
	}
	
	public static void main(String[] args){
		VoteDAO dao = new VoteManageDAO();
//		Vote vote = new Vote(4);
//		dao.add(vote);
//		dao.delete(65);
		System.out.println(dao.getAllVotes());
	}
	
}