page.java

基于JAVAJSP的网上书店系统需要的下载 希望对大家有用

/*先求出有多少页;
再算出总页数;
再算出一共取几个记录;*/
package mybag; 
import java.sql.*;
public class Page {
	final int N=3;
	int total=0;
	int startPage;
	public void Num(){
	try{
	Cn c=new Cn();
	ResultSet r=c.query("select * from book");
	while(r.next()) total++;
	}catch(Exception e){System.out.println("error resultset");};
	
	}


	public void Num(String str){
		try{
		Cn c=new Cn();
		ResultSet r=c.query("select * from book "+str+" ");
		while(r.next())total++;
		}catch(Exception e){}
		}
	

	public int getPageNum(){
			int pageNum;
		if (total%N==0) pageNum=total/N;
		else pageNum=total/N+1;
		if (pageNum==0)pageNum=1;
		return pageNum;
			//防止从0页开始
	}
	public int getTotal(){return total;}
	public int getStart(int s){
		return (s-1)*N;}
}