制作简单的java web项目

package com.dao; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; import com.entity.User; import com.util.DBconn; public class UserDaoImpl implements UserDao{ //插入 public boolean register(User user) { boolean flag = false; DBconn.init(); int i =DBconn.addUpdDel("insert into user(name,pwd,sex,home,info) " + "values('"+user.getName()+"','"+user.getPwd()+"','"+user.getSex()+"','"+user.getHome()+"','"+user.getInfo()+"')"); if(i>0){ flag = true; } DBconn.closeConn(); return flag; } //登陆验证 public boolean login(String name, String pwd) { boolean flag = false; try { DBconn.init(); ResultSet rs = DBconn.selectSql("select * from user where name='"+name+"' and pwd='"+pwd+"'"); while(rs.next()){ if(rs.getString("name").equals(name) && rs.getString("pwd").equals(pwd)){ flag = true; } } DBconn.closeConn(); } catch (SQLException e) { e.printStackTrace(); } return flag; } //查询 public List<User> getUserAll() { List<User> list = new ArrayList<User>(); try { DBconn.init(); ResultSet rs = DBconn.selectSql("select * from user"); while(rs.next()){ User user = new User(); user.setId(rs.getInt("id")); user.setName(rs.getString("name")); user.setPwd(rs.getString("pwd")); user.setSex(rs.getString("sex")); user.setHome(rs.getString("home")); user.setInfo(rs.getString("info")); list.add(user); } DBconn.closeConn(); return list; } catch (SQLException e) { e.printStackTrace(); } return null; } //修改 public boolean update(int id,String name, String pwd,String sex, String home,String info) { boolean flag = false; DBconn.init(); String sql ="update user set name ='"+name +"' , pwd ='"+pwd +"' , sex ='"+sex +"' , home ='"+home +"' , info ='"+info+"' where id = "+id; int i =DBconn.addUpdDel(sql); if(i>0){ flag = true; } DBconn.closeConn(); return flag; } //删除 public boolean delete(int id) { boolean flag = false; DBconn.init(); String sql = "delete from user where id="+id; int i =DBconn.addUpdDel(sql); if(i>0){ flag = true; } DBconn.closeConn(); return flag; } }