pagebean.java

网上购书系统 采用jsp+servlet+sql2000

package bean;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.Vector;

import base.DaoBase;

public class PageBean {

	private int recordcount;
	private int recordperpage=5;
	private int maximumpage;
	private int currentpage;
	private Vector pagecontent=new Vector();
	
	private PageBean(){
		
	}
	
	public PageBean(int currentpage){
		setRecordcount();
		setMaximumpage();
		setCurrentpage(currentpage);
	}
	
	private void setRecordcount(){
		int recordcount=0;
		Connection conn=null;
		Statement stat=null;
		String sql=null;
		ResultSet rest=null;
		try{
		DaoBase daobase=new DaoBase();
		conn=daobase.getConn();
		stat=conn.createStatement();
		sql="select count(*) from book";
		rest=stat.executeQuery(sql);
		if(rest.next()){
			recordcount=rest.getInt(1);
		}
		rest.close();
		stat.close();
		daobase.closeConn();
		this.recordcount=recordcount;
		}catch(Exception ex){
			ex.printStackTrace();
		}
	}
	
	private void setMaximumpage(){
		if(recordcount%recordperpage==0){
			this.maximumpage=recordcount/recordperpage;
		}else{
			this.maximumpage=recordcount/recordperpage+1;
		}
	}
	
	public int getMaximumpage(){
		return this.maximumpage;
	}
	
	private void setCurrentpage(int currentpage){
		this.currentpage=currentpage;
	}
	
	public int getCurrentpage(){
		return this.currentpage;
	}
	
	public PageBean getPageBean(){
		
		DaoBase daobase=new DaoBase();
		Connection conn=daobase.getConn();
		try{
			Statement stat=conn.createStatement();
			String sql="select top " + (recordperpage*currentpage) + " * from book";
			ResultSet rest=stat.executeQuery(sql);
			
			int i=0;
			Object[] objs=null;
			while(rest.next()){
				if(i++>((currentpage-1)*recordperpage-1)){
					objs=new Object[8];
					objs[0]=rest.getInt(1);
					objs[1]=rest.getString(2);
					objs[2]=rest.getString(3);
					objs[3]=rest.getString(4);
					objs[4]=rest.getString(5);
					objs[5]=rest.getString(6);
					objs[6]=rest.getFloat(7);
					objs[7]=rest.getString(8);
					pagecontent.add(objs);
				}
			}
			
			rest.close();
			stat.close();
		}catch(Exception ex){
			ex.printStackTrace();
		}
		daobase.closeConn();
		return this;
	}
	
	public int getRecordperpage(){
		return this.recordperpage;
	}
	
	public Vector getPagecontent(){
		return this.pagecontent;
	}
}