userbeancl.java

简单的M2样式

package com.qs.model;

import java.sql.*;
import java.util.*;

public class UserBeanCl {
	
	private Statement sm=null;
	private ResultSet rs=null;
	private Connection ct=null;
	private int pageSize=4;
	private int pageCount=0;
	private int rowCount=0;
	
	
	public int getPageCount(){
		try{
			ct=new ConnDB().getConn();
			sm=ct.createStatement();
            rs=sm.executeQuery("select count (*) from users");
	        
	     	if(rs.next()){
	     		rowCount=rs.getInt(1);
	     	
	     	}
	     	if(rowCount%pageSize==0){
	     	
	     		pageCount=(rowCount/pageSize);
	     	
	     	}
	     	else{
	     	
	     		pageCount=(rowCount/pageSize+1);
	     	
	     	}
		}catch(Exception e){
			e.printStackTrace();
		}finally{
			this.close();
			
		}
		return pageCount;
	
	}
	public ArrayList getUserByPage(int pageNow){
		
		
		ArrayList<UserBean> al=new ArrayList<UserBean>();
		try{
	           //创建查询
			ct=new ConnDB().getConn();
	        sm=ct.createStatement();
	        
	     	rs=sm.executeQuery("select top "+pageSize+" * from users where userId not in (select top "+
	                    pageSize*(pageNow-1)+" userId from users)");
	     	while(rs.next()){
	     		UserBean ub=new UserBean();
	     		ub.setUserId(rs.getInt(1));
	     		ub.setUsername(rs.getString(2));
	     		ub.setPasswd(rs.getString(3));
	     		ub.setEmail(rs.getString(4));
	     		ub.setGrade(rs.getInt(5));
	     		al.add(ub);
	     	}
			
		}catch(Exception e){
			
			e.printStackTrace();
		}finally{
			this.close();
		}
		return al;
	}
	public void close(){
		try{
			if(rs!=null){
				
				rs.close();
				rs=null;
			}
			if(sm!=null){
				
				sm.close();
				sm=null;
			}
			if(ct!=null){
				
				ct.close();
				ct=null;
			}
		}catch(Exception e){
			e.printStackTrace();
		}
		
	}
	
	public boolean checkUser(String u,String p){
		
		boolean b=false;
		
		try{
			
			 ct=new ConnDB().getConn();
            //创建查询
             sm=ct.createStatement();
             rs=sm.executeQuery("select passwd  from users where username='"+u+"'");
             //判断结果
		     if(rs.next()){
		     		if(rs.getString(1).equals(p)){
		     			b=true;
		     		}
		     }
		     
			
		}
		catch(Exception e){
			
			e.printStackTrace();
		}
		finally{
			this.close();
		}
		return b;
	}

}