简单的分页查询功能 jsp mysql

package com.buat.test.dao; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; import com.buat.test.vo.UserVo; public class UserDAO { Connection con = null; PreparedStatement pst = null; ResultSet rs = null; int counts = 0; int pageNum = 0; public boolean addResult(UserVo vo){ boolean result = false; int addResult = 0; String addSql = new String(); addSql = "insert into user(userName,userPass,userEmail,userAddress) values(?,?,?,?)"; con = GetConnection.getConnect(); System.out.println(vo.getUserName()); System.out.println(vo.getUserPass()); System.out.println(vo.getUserEmail()); try { pst = con.prepareStatement(addSql); pst.setString(1, vo.getUserName()); pst.setString(2, vo.getUserPass()); pst.setString(3, vo.getUserEmail()); pst.setString(4, vo.getUserAddress()); addResult = pst.executeUpdate(); if(addResult!=0){ result = true; System.out.print("添加成功"); } } catch (SQLException e) { // TODO 自动生成 catch 块 e.printStackTrace(); } return result; } public List getUserInfoByName(UserVo vo){ List list = new ArrayList(); String getInfoByName = new String(); getInfoByName = "select * from user where userName = ?"; con = GetConnection.getConnect(); try { pst = con.prepareStatement(getInfoByName); pst.setString(1, vo.getUserName()); rs = pst.executeQuery(); while(rs.next()){ UserVo user = new UserVo(); user.setUserName(rs.getString("userName")); user.setUserPass(rs.getString("userPass")); user.setUserEmail(rs.getString("userEmail")); user.setUserAddress(rs.getString("userAddress")); list.add(user); } } catch (SQLException e) { // TODO 自动生成 catch 块 e.printStackTrace(); } return list; } public List getUser(int counts,int pageNum){ List list = new ArrayList(); con = GetConnection.getConnect(); String getInfo = new String(); if(pageNum==1){ getInfo = "select top " + counts + " * from user "; }else{ getInfo="select top " + counts + " * from user where userId not in ( select top " + counts*(pageNum-1) + " userId from user)"; } try { pst = con.prepareStatement(getInfo); rs = pst.executeQuery(); while(rs.next()){ UserVo user = new UserVo(); user.setUserName(rs.getString("userName")); user.setUserPass(rs.getString("userPass")); user.setUserEmail(rs.getString("userEmail")); user.setUserAddress(rs.getString("userAddress")); list.add(user); } } catch (SQLException e) { // TODO 自动生成 catch 块 e.printStackTrace(); } return list; } public int maxPage(int counts){ int maxPage = 0; int rows = 0; String maxSql = new String(); maxSql = "select count(*) from user"; try { pst = con.prepareStatement(maxSql); rs = pst.executeQuery(); while(rs.next()){ rows = rs.getInt(1); } if(rows%counts==0){ maxPage = rows/counts; }else{ maxPage = rows/counts+1; } } catch (SQLException e) { // TODO 自动生成 catch 块 e.printStackTrace(); } return maxPage; } }