JAVA Web留言板 （JSP SERVLET验证码）

package com.mstanford.MessagesBoard.Bean; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import javax.servlet.jsp.jstl.sql.Result; import javax.servlet.jsp.jstl.sql.ResultSupport; import com.mstanford.MessagesBoard.util.DBUtil; public class MesuserDao { private Connection conn = null; private PreparedStatement pstmt = null; private ResultSet rs = null; private Statement stmt = null; public void insert(Object[] params) { String sql = "insert into [Mes_user] ([user_Name],[password] ,[Email]) values (?,?,?)"; //Object[] params = { model.getUserName(),model.getPassword()}; try { conn = DBUtil.getConn();// 获得数据库连接对象 // 使用带参数的sql语句创建PreparedStatement对象 pstmt = conn.prepareStatement(sql); DBUtil.bindParams(pstmt, params);// 设置sql语句中的参数值 pstmt.executeUpdate();// 执行sql语句 } catch (Exception e) { e.printStackTrace(); } finally { DBUtil.colseDB(rs, pstmt, pstmt, conn);// 关闭资源 } } public void Delete(Mesuser model) { Delete(model.getId()); } public void Delete(int id) { String sql = "delete from Mes_user where [user_Id]=?"; Object[] params = { id }; try { conn = DBUtil.getConn();// 获得数据库连接对象 // 使用带参数的sql语句创建PreparedStatement对象 pstmt = conn.prepareStatement(sql); DBUtil.bindParams(pstmt, params);// 设置sql语句中的参数值 pstmt.executeUpdate();// 执行sql语句 } catch (Exception e) { e.printStackTrace(); } finally { DBUtil.colseDB(rs, pstmt, pstmt, conn);// 关闭资源 } } private Result result=null; /* * 判断用户是否存在 * @param params: */ public Result queryByUser(Object[] params){ String sql="select * from Mes_user where user_Name=? and password=?"; try { conn=DBUtil.getConn(); pstmt=conn.prepareStatement(sql); DBUtil.bindParams(pstmt, params); rs=pstmt.executeQuery(); result=ResultSupport.toResult(rs);//转化为result对象 return result; } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ DBUtil.colseDB(rs, pstmt, pstmt, conn); } return null; } public boolean queryByName(Object[] params){ //添加的sql语句 String sql="select user_Name from Mes_user where user_Name=?"; conn=DBUtil.getConn(); try { pstmt=conn.prepareStatement(sql); DBUtil.bindParams(pstmt, params); rs=pstmt.executeQuery(); if(rs.next()){ return true; } else{ return false; } } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ DBUtil.colseDB(rs, pstmt, pstmt, conn); } return false; } }