aaa.rar_留言板

package com.lx.model; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.util.ArrayList; import java.util.List; import cn.mldn.lxh.dao.noteBean_dao; public class notesBean_conf implements noteBean_dao { private Connection con; private PreparedStatement pstmt; private ResultSet rs; private boolean b; private int pageCount=0; private int pageSize=5; private int pageNow=0; private int rowCount=0; //获得一共分多少页 public int getPageCount() { //计算页数 try { String sql="select count(*) from notes"; con = new DBCon().getCon(); pstmt=con.prepareStatement(sql); rs = pstmt.executeQuery(); 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 { this.close(); } return pageCount; } // 显示每页的内容 public List queryAll(int pageNow) throws Exception { List all = new ArrayList(); notes_Bean nb = null; this.pageNow=pageNow; try { String sql = "select top " + pageSize + " * from notes where id not in (select top " + pageSize * (pageNow - 1) + " id from notes) "; con = new DBCon().getCon(); pstmt = con.prepareStatement(sql); rs=pstmt.executeQuery(); while (rs.next()) { nb = new notes_Bean(); nb.setId(rs.getInt(1)); nb.setTitle(rs.getString(2)); nb.setAutor(rs.getString(3)); nb.setDatetime(rs.getString(4)); nb.setContent(rs.getString(5)); all.add(nb); } } catch (Exception e) { e.printStackTrace(); } finally { this.close(); } return all; } public boolean insert(notes_Bean nb) { int i = 0; b = false; try { String title = new String(nb.getTitle().getBytes("ISO-8859-1"), ("GB2312")); String autor = new String(nb.getAutor().getBytes("ISO-8859-1"), ("GB2312")); String datetime = nb.getDatetime(); String content = new String(nb.getContent().getBytes("ISO-8859-1"), ("GB2312")); String sql = "insert into notes(title,autor,datetime,content) values(?,?,?,?)"; con = new DBCon().getCon(); pstmt = con.prepareStatement(sql); pstmt.setString(1, title); pstmt.setString(2, autor); pstmt.setString(3, datetime); pstmt.setString(4, content); i = pstmt.executeUpdate(); if (i > 0) { b = true; } } catch (Exception e) { e.printStackTrace(); } finally { this.close(); } return b; } public boolean update(notes_Bean nb, int id) { int i = 0; b = false; try { String title = new String(nb.getTitle().getBytes("ISO-8859-1"), "GB2312"); String autor = new String(nb.getAutor().getBytes("ISO-8859-1"), "GB2312"); String datetime = nb.getDatetime(); String content = new String(nb.getContent().getBytes("ISO-8859-1"), "GB2312"); String sql = "update notes set title=? ,autor=?,datetime=?,content=? where id=?"; con = new DBCon().getCon(); pstmt = con.prepareStatement(sql); pstmt.setString(1, title); pstmt.setString(2, autor); pstmt.setString(3, datetime); pstmt.setString(4, content); pstmt.setInt(5, id); i = pstmt.executeUpdate(); if (i > 0) { b = true; } } catch (Exception e) { e.printStackTrace(); } finally { this.close(); } return b; } public boolean delete(int id) { int i = 0; b = false; try { String sql = "delete from notes where id=?"; con = new DBCon().getCon(); pstmt = con.prepareStatement(sql); pstmt.setInt(1, id); i = pstmt.executeUpdate(); if (i > 0) { b = true; } } catch (Exception e) { e.printStackTrace(); } finally { this.close(); } return b; } public notes_Bean queryById(int id) throws Exception { notes_Bean nb = null; String sql = "SELECT * FROM notes WHERE id=?"; // 下面是针对数据库的具体操作 try { // 连接数据库 con = new DBCon().getCon(); pstmt = con.prepareStatement(sql); pstmt.setInt(1, id); // 进行数据库查询操作 ResultSet rs = pstmt.executeQuery(); if (rs.next()) { // 查询出内容，之后将查询出的内容赋值给person对象 nb = new notes_Bean(); nb.setId(rs.getInt(1)); nb.setTitle(rs.getString(2)); nb.setAutor(rs.getString(3)); nb.setDatetime(rs.getString(4)); nb.setContent(rs.getString(5)); } } catch (Exception e) { e.printStackTrace(); } finally { // 关闭数据库连接 this.close(); } return nb; } public void close() { // 关闭各种打开的资源 try { if (rs != null) { rs.close(); rs = null; } if (pstmt != null) { pstmt.close(); pstmt = null; } if (con != null) { con.close(); con = null; } } catch (Exception e) { e.printStackTrace();// 打印异常，以便修改 } } }