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();

    }

   }

  }

 }

}