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();     }    }   }

}

}