javaweb期末大作业-留言板

package org.dao; import java.sql.*; import org.model.*; import org.db.*; import java.util.ArrayList; public class LoginDao { Connection conn=DBconn.getConn(); //数据库连接对象 PreparedStatement pstmt; public Login checkLogin(String name,String password){ //验证用户名密码 try{ pstmt=conn.prepareStatement("select*from loginss where name=? " + " and password=?"); pstmt.setString(1, name); //设置SQL语句参数 pstmt.setString(2, password); //设置SQL语句参数 ResultSet rs=pstmt.executeQuery(); //执行查询，返回结果集 if(rs.next()){ //通过JavaBean保存值 Login login=new Login(); login.setId(rs.getInt(1)); login.setName(rs.getString(2)); login.setPassword(rs.getString(3)); login.setRole(rs.getInt(4)); return login; //返回JavaBean对象 } return null; //验证失败返回null }catch(Exception e){ e.printStackTrace(); return null; } } public ArrayList<MessBoar> findMbInfo(){ try{ ArrayList<MessBoar> al=new ArrayList<MessBoar>(); pstmt=conn.prepareStatement("select * from messagess"); ResultSet rs=pstmt.executeQuery(); while(rs.next()){ MessBoar mb=new MessBoar(); mb.setId(rs.getInt(1)); mb.setName(rs.getString(2)); mb.setTime(rs.getDate(3)); mb.setTitle(rs.getString(4)); mb.setMessage(rs.getString(5)); al.add(mb); } return al; }catch(Exception e){ e.printStackTrace(); return null; } } public String getName(int id){ String name=null; try{ pstmt=conn.prepareStatement("select name from loginss where id=?"); pstmt.setInt(1, id); ResultSet rs=pstmt.executeQuery(); while(rs.next()){ name=rs.getString(1); } return name; }catch(Exception e){ e.printStackTrace(); return null; } } public boolean addInfo(MessBoar mb){ try{ pstmt=conn.prepareStatement("insert into messagess values(?,?,?,?,?)"); pstmt.setInt(1, mb.getId()); pstmt.setString(2, mb.getName()); pstmt.setDate(3, mb.getTime()); pstmt.setString(4, mb.getTitle()); pstmt.setString(5, mb.getMessage()); pstmt.executeUpdate(); return true; }catch(Exception e){ e.printStackTrace(); return false; } } public boolean insertUser(int id,String name,String password){ try{ pstmt=conn.prepareStatement("insert into loginss values(?,?,?,?)"); pstmt.setInt(1, id); pstmt.setString(2, name); pstmt.setString(3, password); pstmt.setInt(4, 0); pstmt.executeUpdate(); return true; }catch(Exception e){ e.printStackTrace(); return false; } } }