JSP读取MySql数据库实现分页效果

下面是用MV模式做的一个简单的登录后实现分页显示数据信息的页面，后面会用MVC模式改写。

package com.ly.model;

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

public class UserbeanCl {
 private Statement st = null;
 private ResultSet rs = null;
 private Connection ct = null;
 private int pageSize = 10;
 private int rowCount = 0;
 private int pageCount = 0;

//得到应显示的页码数

 public int pageCount() {
  try {
   // 得到连接
   ct = new connDB().getConn(); 
   st=ct.createStatement();
   rs = st.executeQuery("select count(*) from students");
   //
   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 {
   shutup();
  }
  return pageCount;

 }

// 返回分页信息，用ArrayList对象存储

 public ArrayList getUsersByPage(int PageNow) {
  pageCount = pageCount(); 
  
  ct = new connDB().getConn(); 
  int startRow=(PageNow-1)*pageSize;
  ArrayList al = new ArrayList();
  
  try {
   st = ct.createStatement();
   rs=st.executeQuery("SELECT * FROM `students` LIMIT "+startRow+","+pageSize);
   while(rs.next()){
    
    Userbean ub=new Userbean();
    ub.setId(rs.getInt(1));
    ub.setName(rs.getString(2));
    ub.setGrade(rs.getInt(3));
    ub.setBatch(rs.getInt(4));
    ub.setPassword(rs.getInt(5));
    ub.setGxqm(rs.getString(6));
    al.add(ub);
    
   }

  } catch (Exception e) {
    e.printStackTrace();
  } finally {
   shutup();
  }

  return al;

 }

//验证用户登录

 public boolean checkUser(String u, String p) {
  boolean b = false;
  ct = new connDB().getConn();
  try {
   st = ct.createStatement();
   ResultSet rs = st
     .executeQuery("select password from students where name='"
       + u + "'");
   if (rs.next()) {
    // 说明用户名存在
    if (rs.getString(1).equals(p)) {
     // 密码正确
     b = true;
    } else {
     return false;
    }
   }

  } catch (Exception e) {
   e.printStackTrace();
  } finally {
   shutup();
  }
  return b;

 }

// 关闭连接释放资源

 public void shutup() {

  try {
   if (rs != null)
    rs.close();
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } finally {
   try {
    if (st != null)
     st.close();
   } catch (SQLException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   } finally {
    try {
     if (ct != null)
      ct.close();
    } catch (SQLException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
   }
  }

 }

}