struts2 CRUD

// 具体实现DAO接口的类 package org.lxh.daoimpl ; // 需要连接数据库 // 需要对VO的内容进行具体的验证 import java.sql.* ; import java.util.List; import org.lxh.dao.* ; import org.lxh.dbc.* ; import org.lxh.factory.DAOFactory; import org.lxh.vo.* ; import java.util.List; import java.util.ArrayList; public class PersonDAOImpl implements PersonDAO { //验证登录，已实现 public boolean isLogin(PersonVo pv) { boolean flag = false ; // 在此处成具体的数据库验证 // 声明一个数据库操作对象 PreparedStatement pstmt = null ; // 声明一个结果集对象 ResultSet rs = null ; // 声明一个SQL变量，用于保存SQL语句 String sql = null ; // DataBaseConnection为具体的数据库连接及关闭操作类 DataBaseConnection dbc = null ; // 连接数据库 dbc = new DataBaseConnection() ; // 编写SQL语句 sql = "SELECT * FROM person WHERE name=? and password=?" ; try { // 实例化数据库操作对象 pstmt = dbc.getConnection().prepareStatement(sql) ; // 设置pstmt的内容，是按ID和密码验证 pstmt.setString(1,pv.getName()) ;//设置pstmt第一个?号的值 pstmt.setString(2,pv.getPassword()) ;//设置pstmt第二个?号的值 // 查询记录 rs = pstmt.executeQuery() ; // 判断是否有记录 if(rs.next()) { // 如果有记录，则执行此段代码 // 用户是合法的，可以登陆 flag = true ; } // 依次关闭 rs.close() ; pstmt.close() ; } catch(Exception e) { System.out.println(e) ; } finally { // 最后一定要保证数据库已被关闭 dbc.close() ; } return flag ; } //插入数据 public void insert(PersonVo pv) throws Exception { // TODO Auto-generated method stub String sql = "INSERT INTO person(name,password) VALUES(?,?)" ; PreparedStatement pstmt = null ; DataBaseConnection dbc = null ; dbc = new DataBaseConnection() ; try { pstmt = dbc.getConnection().prepareStatement(sql) ; pstmt.setString(1,pv.getName()) ; pstmt.setString(2,pv.getPassword()) ; pstmt.executeUpdate() ; pstmt.close() ; } catch (Exception e) { // System.out.println(e) ; throw new Exception("操作中出现错误！！！") ; } finally { dbc.close() ; } } public void delete(int id) throws Exception { // TODO Auto-generated method stub String sql = "DELETE FROM person 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() ; } } //更新 public void update(PersonVo pv) throws Exception { // TODO Auto-generated method stub String sql = "update person set name=?,password=? where id=?" ; PreparedStatement pstmt = null ; DataBaseConnection dbc = null ; dbc = new DataBaseConnection() ; try { pstmt = dbc.getConnection().prepareStatement(sql) ; pstmt.setString(1,pv.getName()) ; pstmt.setString(2,pv.getPassword()) ; pstmt.setInt(3,pv.getId()); pstmt.executeUpdate() ; pstmt.close() ; } catch (Exception e) { // System.out.println(e) ; throw new Exception("操作中出现错误！！！") ; } finally { dbc.close() ; } } //根据id根据,用于更新 public List queryById(int id) throws Exception { List list=new ArrayList(); PersonVo pv=null; String sql="select id,name,password from person where id=?"; PreparedStatement pstmt=null; DataBaseConnection dbc=null; dbc=new DataBaseConnection(); try { pstmt=dbc.getConnection().prepareStatement(sql);//预编译sql pstmt.setInt(1, id); ResultSet rs=pstmt.executeQuery();//执行操作，返回结果集 while(rs.next())//循环读取结果 { pv=new PersonVo();//实例化PersonVo pv.setId(rs.getInt(1)); pv.setName(rs.getString(2)); pv.setPassword(rs.getString(3)); list.add(pv);//将user对象中加入到list集合中 } } catch(Exception e) { throw new Exception("操作错误!"); } finally { dbc.close(); } return list; } //查询全部,已实现 public List<PersonVo> queryAll() throws Exception { // TODO Auto-generated method stub List<PersonVo> all=new ArrayList(); PersonVo pv=null; String sql="select id,name,password from person "; PreparedStatement pstmt=null; DataBaseConnection dbc=null; dbc=new DataBaseConnection(); try { pstmt=dbc.getConnection().prepareStatement(sql);//预编译sql ResultSet rs=pstmt.executeQuery();//执行操作，返回结果集 while(rs.next())//循环读取结果 { pv=new PersonVo();//实例化PersonVo pv.setId(rs.getInt(1)); pv.setName(rs.getString(2)); pv.setPassword(rs.getString(3)); all.add(pv);//将user对象中加入到list集合中 } } catch(Exception e) { throw new Exception("操作错误!"); } finally { dbc.close(); } return all; } //模糊查询 public List queryByLike(String cond) throws Exception { // TODO Auto-generated method stub List all=new ArrayList(); PersonVo pv=null; String sql="select id,name,pwd from person where name like ? or password like ?"; PreparedStatement pstmt=null; DataBaseConnection dbc=null; dbc=new DataBaseConnection(); try { pstmt=dbc.getConnection().prepareStatement(sql);//预编译sql pstmt.setString(1,"%"+cond+"%") ; pstmt.setString(2,"%"+cond+"%") ; ResultSet rs=pstmt.executeQuery();//执行操作，返回结果集 while(rs.next())//循环读取结果 { pv=new PersonVo(); pv.setId(rs.getInt(1)); pv.setName(rs.getString(2)); pv.setPassword(rs.getString(3)); all.add(pv);//将user对象中加入到list集合中 } } catch(Exception e) { throw new Exception("操作错误!"); } finally { dbc.close(); } return all; } };