留言本源码（jsp）

package cn.mldn.lxh.note.dao.impl ; import java.sql.* ; import java.util.* ; import cn.mldn.lxh.note.vo.* ; import cn.mldn.lxh.note.dao.* ; import cn.mldn.lxh.note.dbc.* ; public class NoteDAOImpl implements NoteDAO { // 增加操作 public void insert(Note note) throws Exception { String suiji=(int) (Math.random()*10000)+""; String sql = "INSERT INTO note(id,title,author,content) VALUES(?,?,?,?)" ; PreparedStatement pstmt = null ; DataBaseConnection dbc = null ; dbc = new DataBaseConnection() ; try { pstmt = dbc.getConnection().prepareStatement(sql) ; pstmt.setString(1,suiji); pstmt.setString(2,note.getTitle()) ; pstmt.setString(3,note.getAuthor()) ; pstmt.setString(4,note.getContent()) ; pstmt.executeUpdate() ; pstmt.close() ; } catch (Exception e) { // System.out.println(e) ; throw new Exception("操作中出现错误！！！") ; } finally { dbc.close() ; } } // 修改操作 public void update(Note note) throws Exception { String sql = "UPDATE note SET title=?,author=?,content=? WHERE id=?" ; PreparedStatement pstmt = null ; DataBaseConnection dbc = null ; dbc = new DataBaseConnection() ; try { pstmt = dbc.getConnection().prepareStatement(sql) ; pstmt.setString(1,note.getTitle()) ; pstmt.setString(2,note.getAuthor()) ; pstmt.setString(3,note.getContent()) ; pstmt.setInt(4,note.getId()) ; pstmt.executeUpdate() ; pstmt.close() ; } catch (Exception e) { throw new Exception("操作中出现错误！！！") ; } finally { dbc.close() ; } } // 删除操作 public void delete(int id) throws Exception { String sql = "DELETE FROM note WHERE id=?" ; PreparedStatement pstmt = null ; DataBaseConnection dbc = null ; dbc = new DataBaseConnection() ; try { pstmt = dbc.getConnection().prepareStatement(sql) ; pstmt.setInt(1,id) ; pstmt.executeUpdate() ; pstmt.close() ; } catch (Exception e) { throw new Exception("操作中出现错误！！！") ; } finally { dbc.close() ; } } // 按ID查询，主要为更新使用 public Note queryById(int id) throws Exception { Note note = null ; String sql = "SELECT id,title,author,content FROM note WHERE id=?" ; PreparedStatement pstmt = null ; DataBaseConnection dbc = null ; dbc = new DataBaseConnection() ; try { pstmt = dbc.getConnection().prepareStatement(sql) ; pstmt.setInt(1,id) ; ResultSet rs = pstmt.executeQuery() ; if(rs.next()) { note = new Note() ; note.setId(rs.getInt(1)) ; note.setTitle(rs.getString(2)) ; note.setAuthor(rs.getString(3)) ; note.setContent(rs.getString(4)) ; } rs.close() ; pstmt.close() ; } catch (Exception e) { throw new Exception("操作中出现错误！！！") ; } finally { dbc.close() ; } return note ; } // 查询全部 public List queryAll() throws Exception { List all = new ArrayList() ; String sql = "SELECT id,title,author,content FROM note" ; PreparedStatement pstmt = null ; DataBaseConnection dbc = null ; dbc = new DataBaseConnection() ; try { pstmt = dbc.getConnection().prepareStatement(sql) ; ResultSet rs = pstmt.executeQuery() ; while(rs.next()) { Note note = new Note() ; note.setId(rs.getInt(1)) ; note.setTitle(rs.getString(2)) ; note.setAuthor(rs.getString(3)) ; note.setContent(rs.getString(4)) ; all.add(note) ; } rs.close() ; pstmt.close() ; } catch (Exception e) { System.out.println("查询全部出错了"); System.out.println(e) ; throw new Exception("操作中出现错误！！！") ; } finally { dbc.close() ; } return all ; } // 模糊查询 public List queryByLike(String cond) throws Exception { List all = new ArrayList() ; String sql = "SELECT id,title,author,content FROM note WHERE title LIKE ? or AUTHOR LIKE ? or CONTENT LIKE ?" ; PreparedStatement pstmt = null ; DataBaseConnection dbc = null ; dbc = new DataBaseConnection() ; try { pstmt = dbc.getConnection().prepareStatement(sql) ; pstmt.setString(1,"%"+cond+"%") ; pstmt.setString(2,"%"+cond+"%") ; pstmt.setString(3,"%"+cond+"%") ; ResultSet rs = pstmt.executeQuery() ; while(rs.next()) { Note note = new Note() ; note.setId(rs.getInt(1)) ; note.setTitle(rs.getString(2)) ; note.setAuthor(rs.getString(3)) ; note.setContent(rs.getString(4)) ; all.add(note) ; } rs.close() ; pstmt.close() ; } catch (Exception e) { System.out.println(e) ; throw new Exception("操作中出现错误！！！") ; } finally { dbc.close() ; } return all ; } };