Struts_DAO 实现分页

/** * */ package com.wtt.page.impl; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.util.ArrayList; import java.util.List; import com.wtt.page.dao.PersonDAO; import com.wtt.page.dbc.DataBaseConnection; import com.wtt.page.vo.Person; /** * @author 王田甜 tim_wang * */ public class PersonDAOImpl implements PersonDAO { private DataBaseConnection dbc = null; // 在构造方法里实现数据的连接 public PersonDAOImpl() { this.dbc = new DataBaseConnection(); } // 获取数据库总记录数 public int getAllCount() throws Exception { int count = 0; String sql = "SELECT COUNT(id) from person"; PreparedStatement pstmt = null; try { pstmt = this.dbc.getConnection().prepareStatement(sql); ResultSet rs = pstmt.executeQuery(); if (rs.next()) { count = rs.getInt(1); } pstmt.close(); rs.close(); } catch (Exception e) { throw e; } return count; } // 根据传过来的参数进行模糊查询 public int getByLikeCount(String cond) throws Exception { int count = 0; String sql = "SELECT COUNT(id) from person WHERE uid LIKE ? OR name LIKE ?"; PreparedStatement pstmt = null; try { pstmt = this.dbc.getConnection().prepareStatement(sql); pstmt.setString(1, "%" + cond + "%"); pstmt.setString(2, "%" + cond + "%"); ResultSet rs = pstmt.executeQuery(); if (rs.next()) { count = rs.getInt(1); } pstmt.close(); rs.close(); } catch (Exception e) { throw e; } return count; } // 根据传过来的当前页数和每页大小数进行查询全部 public List queryAll(int currentPage, int lineSize) throws Exception { // 使用了泛型 List<Person> all = new ArrayList<Person>(); // 从数据里只查询符合指定大小的全部的记录 String sql = "SELECT id,uid,name,password FROM person limit " + (currentPage - 1) * lineSize + "," + lineSize; PreparedStatement pstmt = null; try { pstmt = this.dbc.getConnection().prepareStatement(sql); ResultSet rs = pstmt.executeQuery(); while (rs.next()) { Person p = new Person(); p.setId(rs.getInt(1)); p.setUid(rs.getString(2)); p.setName(rs.getString(3)); p.setPassword(rs.getString(4)); // 用list保存所有记录 all.add(p); } rs.close(); pstmt.close(); } catch (Exception e) { throw e; } finally { this.dbc.close(); } return all; } // 根据传过来的参数，当前页数和每页大小数进行查询符合条件的数据 public List queryByLike(String cond, int currentPage, int lineSize) throws Exception { List<Person> all = new ArrayList<Person>(); // 从数据里只查询符合条件的记录,带where 查询 String sql = "SELECT id,uid,name,password FROM person WHERE uid LIKE ? OR name LIKE ? limit " + (currentPage - 1) * lineSize + "," + lineSize; PreparedStatement pstmt = null; try { pstmt = this.dbc.getConnection().prepareStatement(sql); pstmt.setString(1, "%" + cond + "%"); pstmt.setString(2, "%" + cond + "%"); ResultSet rs = pstmt.executeQuery(); while (rs.next()) { Person p = new Person(); p.setId(rs.getInt(1)); p.setUid(rs.getString(2)); p.setName(rs.getString(3)); p.setPassword(rs.getString(4)); all.add(p); } rs.close(); pstmt.close(); } catch (Exception e) { throw e; } finally { this.dbc.close(); } return all; } };