webpagedaoimpl.java

一个用JSP编写的网站计数器

package com.webcount.dao;

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


import com.webcount.bean.Web;
import com.webcount.bean.WebPage;
import com.webcount.database.DataConnection;


public class WebPageDAOImpl implements WebPageDAO{

	public boolean insertWebPage(WebPage instance){
		boolean re = false;
		long maxid = getMaxId();
		String currentTime = new Long(System.currentTimeMillis()).toString();
		instance.setPageid(maxid+1);
		String query = "insert into webpage(pageid,pagename,webhost,sessionid,recorddate) values(?,?,?,?,?)";
		Connection conn = DataConnection.getFreeConnection();
		PreparedStatement pstmt = DataConnection.getPreparedStatement(conn,query);
		try{
			pstmt.setLong(1,instance.getPageid());
			pstmt.setString(2,instance.getPagename());
			pstmt.setString(3,instance.getWebhost());
			pstmt.setString(4,instance.getSessionid());
			pstmt.setString(5,currentTime);
			re = DataConnection.execute(pstmt);
		}catch(Exception ex){
			ex.printStackTrace();
		}
		
		return re;
	}
	
	private long getMaxId(){
		String query = "select max(pageid) as maxid from webpage";
		long maxid = 0;
		Connection conn = DataConnection.getFreeConnection();
		Statement st = DataConnection.getStatement(conn);
		ResultSet rs = DataConnection.getResult(st,query);
		try{
			if(rs.next()){
				maxid = rs.getLong("maxid");
			}
		}catch(Exception ex){
			ex.printStackTrace();
		}
		return maxid;
	} 
	
	public List getWebPageByWeb(Web instance){
		ArrayList webpagelist = new ArrayList();
		WebPage webpage = null;
		String query = "select * from webpage where webhost = ?";
		Connection conn = DataConnection.getFreeConnection();
		PreparedStatement pstmt = DataConnection.getPreparedStatement(conn,query);
		ResultSet rs = null;
		try{
			pstmt.setString(1,instance.getWebhost());
			rs = DataConnection.getResult(pstmt);
			while(rs.next()){
				webpage = new WebPage();
				webpage.setPageid(rs.getLong("pageid"));
				webpage.setPagename(rs.getString("pagename"));
				webpage.setWebhost(instance.getWebhost());
				webpage.setSessionid(rs.getString("sessionid"));
				webpage.setRecorddate(rs.getString("recorddate"));
				webpagelist.add(webpage);
			}
		}catch(Exception ex){
			ex.printStackTrace();
		}
		return webpagelist;
	}
}