新闻发布系统实训期间设计后台代码JSP+JAVA

package dal; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import bean.NRC_TYPE; import util.DButil; /*** * * @author 马琳的笔记本<br> *News_type_Dao主要是实现对新闻类别的增删改查的操作实现方法<br> *主要继承与抽象类News_type<br> */ public class News_type_Dao extends News_type{ public static NRC_TYPE type=null; /*** * 1、通过类别名称T_NAME和T_MENO来实现添加操作的添加方法 * @param T_NAME类别名称 * @param T_MENO类别备注 */ public void add(String T_NAME, String T_MENO) { ResultSet rs = null; //1.获得静态数据库连接类连接 Connection conn = DButil.getConn(); //2.定义sql语句 String sql = "insert into NRC_TYPE(T_NAME,T_MEMO) values(?,?)"; //3.创建执行对象 PreparedStatement pstmt = null; try { pstmt = conn.prepareStatement(sql); //给参数（?）赋值 pstmt.setString(1,T_NAME); pstmt.setString(2,T_MENO); int isSucess=pstmt.executeUpdate();; if(isSucess!=0){ System.out.println("插入成功"); }else{ System.out.println("插入不顺利"); } } catch (SQLException e) { e.printStackTrace(); }finally{ //关闭资源 DButil.closeResultSet(rs); DButil.closeStatement(pstmt); DButil.closeConn(conn); } } /*** * 2、通过类别名称T_NAME来实现删除类别新闻的信息 * @param T_NAME类别名称 */ public void deleteNAME(String T_NAME) { int deleteid=queryID(T_NAME); if(deleteid==-1){ System.out.println("不存在，怎么删除？"); }else{ if(deleteID(deleteid)){ System.out.println("删除成功"); }else{ System.out.println("删除不成功"); } } } /*** * 3、删除新闻类别的ID * @param id 传入ID值 * @return 成功返回true，失败返回false； */ public boolean deleteID(int id) { ResultSet rs = null; Connection conn = DButil.getConn(); String sql = "delete from NRC_TYPE where T_ID=?"; PreparedStatement pstmt = null; try { pstmt = conn.prepareStatement(sql); //给参数（?）赋值 pstmt.setInt(1,id); pstmt.executeUpdate(); return true; } catch (SQLException e) { e.printStackTrace(); }finally{ //关闭资源 DButil.closeResultSet(rs); DButil.closeStatement(pstmt); DButil.closeConn(conn); } return false; } /*** * 4、通过类别名称实现查询ID * @param T_name 类别名 * @return 查询到的ID，有为ID，无为0 */ public int queryID(String T_name) { int id=-1; ResultSet rs = null; Connection conn = DButil.getConn(); String sql = "select * from NRC_TYPE where T_NAME=?"; PreparedStatement pstmt = null; try { pstmt = conn.prepareStatement(sql); pstmt.setString(1, T_name); rs = pstmt.executeQuery(); if(rs.next()){ id=rs.getInt("T_ID"); } return id; } catch (SQLException e) { e.printStackTrace(); }finally{ DButil.closeResultSet(rs); DButil.closeStatement(pstmt); DButil.closeConn(conn); } return -1; } /*** * 5、通过类别ID来实现查询，T_ID来实现查询该T_ID的信息新闻方法 * @param T_ID 唯一的ID； * @return 返回一个NRC_TYPE对象 */ public NRC_TYPE query(int T_ID) { type=new NRC_TYPE(); ResultSet rs = null; Connection conn = DButil.getConn(); String sql = "select * from NRC_TYPE where T_ID=?"; PreparedStatement pstmt = null; try { pstmt = conn.prepareStatement(sql); pstmt.setInt(1, T_ID); rs = pstmt.executeQuery(); if(rs.next()){ type.setT_ID(rs.getInt("T_ID")); type.setT_NAME(rs.getString("T_NAME")); type.setT_MEMO(rs.getString("T_MEMO")); } return type; } catch (SQLException e) { e.printStackTrace(); }finally{ DButil.closeResultSet(rs); DButil.closeStatement(pstmt); DButil.closeConn(conn); } return null; } /*** *6、查询类别名称。不能有重复；实现验证操作 * @param T_name 传入类别名称值 * @return true为重复，false为唯一 */ public boolean queryNAME(String T_name) { ResultSet rs = null; Connection conn = DButil.getConn(); String sql = "select * from NRC_TYPE where T_NAME=?"; PreparedStatement pstmt = null; try { pstmt = conn.prepareStatement(sql); pstmt.setString(1, T_name); rs = pstmt.executeQuery(); if(rs.next()){ System.out.println("出现相同的名字"); return true; } } catch (SQLException e) { e.printStackTrace(); }finally{ DButil.closeResultSet(rs); DButil.closeStatement(pstmt); DButil.closeConn(conn); } return false; } /*** *7、实现查询最后一列，返回查询到对象，实现实时验证插入是否成功 * @return NRC_TYPE对象 */ public NRC_TYPE queryLastline() { type=new NRC_TYPE(); ResultSet rs = null; Connection conn = DButil.getConn(); String sql = "SELECT TOP 1 * from NRC_TYPE ORDER BY T_ID DESC "; PreparedStatement pstmt = null; try { pstmt = conn.prepareStatement(sql); rs = pstmt.executeQuery(); if(rs.next()){ type.setT_ID(rs.getInt("T_ID")); type.setT_NAME(rs.getString("T_NAME")); type.setT_MEMO(rs.getString("T_MEMO")); return type; } } catch (SQLException e) { e.printStackTrace(); }finally{ DButil.closeResultSet(rs); DButil.closeStatement(pstmt); DButil.closeConn(conn); } return null; } /*** * 8、通过新闻的T_ID实现修改该T_ID的类别信息方法 * @param T_ID 找到id * @param T_NAME 新的类别名称 * @param T_MEMO 新的备注 */ public void update(int T_ID,String T_NAME,String T_MEMO) { ResultSet rs = null; Connection conn = DButil.getConn(); String sql = "update NRC_TYPE set T_NAME=?,T_MEMO=? where T_ID=?"; PreparedStatement pstmt = null; try { pstmt = conn.prepareStatement(sql); pstmt.setString(1, T_NAME); pstmt.setString(2, T_MEMO); pstmt.setInt(3, T_ID); pstmt.executeUpdate(); } catch (SQLException e) { e.printStackTrace(); }finally{ DButil.closeResultSet(rs); DButil.closeStatement(pstmt); DButil.closeConn(conn); } } /*** *9、列表所有新闻类别查询方法 * @return 返回一个ArrayList<NRC_TYPE> */ public ArrayList<NRC_TYPE> queryall() { ArrayList<NRC_TYPE> list=new ArrayList<NRC_TYPE>(); type=null; ResultSet rs = null; Connection conn = DButil.getConn(); String sql = "select * from NRC_TYPE"; PreparedStatement pstmt = null; try { pstmt = conn.prepareStatement(sql); rs = pstmt.executeQuery(); while(rs.next()){ type = new NRC_TYPE(); type.setT_ID(rs.getInt("T_ID")); type.setT_NAME(rs.getString("T_NAME")); type.setT_MEMO(rs.getString("T_MEMO")); list.add(type); /*System.out.println("序号："+rs.getInt("T_ID")); System.out.println("类别："+rs.getString("T_NAME")); System.out.println("备注："+rs.getString("T_MEMO"));*/ } return list; } catch (SQLException e) { e.printStackTrace(); }finally{ DButil.closeResultSet(rs); DButil.closeStatement(pstmt); DButil.closeConn(conn); } return list; } }