中英文网站用一个域名还是两个域名利于优化,网站做,网站创建需要什么,网站关键词如何优化思考 #xff1a; 需要创建实体类吗? 需要创建表吗 |----User 存在、不需要创建了#xff01;表同理、也不需要了 1.设计dao接口 package cn.javabs.usermanager.dao;import cn.javabs.usermanager.entity.User;/*** 用户的dao接口的设计* author Mryang**/
public interfa… 思考 需要创建实体类吗? 需要创建表吗 |----User 存在、不需要创建了表同理、也不需要了 1.设计dao接口 package cn.javabs.usermanager.dao;import cn.javabs.usermanager.entity.User;/*** 用户的dao接口的设计* author Mryang**/
public interface UserDao {/*** 用户登录功能* param username 参数 为用户名* param password 参数 为密码* return user*/User login(String username , String password);/*** 用户注册* param user 参数是 用户对象* return 记录条数 受影响的行数*/int register(User user);}2.UserDaoImpl 实现类 package cn.javabs.usermanager.dao.impl;import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;import cn.javabs.usermanager.dao.UserDao;
import cn.javabs.usermanager.entity.User;
import cn.javabs.usermanager.exception.UserLoginException;
import cn.javabs.usermanager.exception.UserRegisterException;
import cn.javabs.usermanager.util.JdbcUtil;
/*** userdao的实现类* author Mryang* 调用 jdbc**静态方法优于构造方法先执行**/
public class UserDaoImpl implements UserDao {Overridepublic User login(String username, String password) {try {Connection con JdbcUtil.getConnection();// 通过con 链接创建一个执行SQL语句的对象StatementStatement st con.createStatement();ResultSet rs st.executeQuery(select * from user where username username and password password;);if(rs.next()){// 有数据才执行以下// 类型 对象 。。。User user new User();// rs.getString();//columnIndex 数据库中表的列号 从0计数
// rs.getString(columnLabel)//columnLabel 数据库中表的列名// String name rs.getString(username);//name admin
// String pwd rs.getString(password);//name admin
// System.out.println(name:name);
// System.out.println(pwd:pwd);
// user.setUsername(name);// 封装。注入user.setUsername(rs.getString(username));user.setPassword(rs.getString(password));System.out.println(userDao中的user的内容是 user);return user;// 已经有了 username和password}else{//没数据才执行以下return null;}} catch (SQLException e) {throw new UserLoginException();}}Overridepublic int register(User user) {try {// 获取链接Connection conn JdbcUtil.getConnection();// 创建执行SQL语句的对象Statement st conn.createStatement();int row st.executeUpdate(insert into user(username,password,sex) values (user.getUsername(),user.getPassword(),user.getSex()));return row;} catch (SQLException e) {throw new UserRegisterException();}}}3.service接口设计 package cn.javabs.usermanager.service;import cn.javabs.usermanager.entity.User;public interface UserService {/*** 用户登录功能* param username 参数 为用户名* param password 参数 为密码* return user*/User userLogin(String username , String password);/*** 用户注册* param user* return*/int userRegist(User user);}serviceImpl package cn.javabs.usermanager.service.impl;import cn.javabs.usermanager.dao.UserDao;
import cn.javabs.usermanager.dao.impl.UserDaoImpl;
import cn.javabs.usermanager.entity.User;
import cn.javabs.usermanager.service.UserService;public class UserServiceImpl implements UserService {// 采用多态的形式进行实例化dao UserDao dao new UserDaoImpl();Overridepublic User userLogin(String username, String password) {//dao代表的是UserDao 这个接口
// .login 用这个接口中的用户登录功能 并且传了两个参数给你return dao.login(username, password);}Overridepublic int userRegist(User user) {return dao.register(user);}}UserServlet package cn.javabs.usermanager.web.servlet;import java.io.IOException;import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import cn.javabs.usermanager.entity.User;
import cn.javabs.usermanager.service.UserService;
import cn.javabs.usermanager.service.impl.UserServiceImpl;public class UserLoginServlet extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {/** 1 set encoding*/response.setContentType(text/html);response.setCharacterEncoding(utf-8);request.setCharacterEncoding(utf-8);/** 2. get 前台 的 参数*/String username request.getParameter(username);String password request.getParameter(password);/** 3. 将获取到的用户名和密码传递给 userService!* 所以 得有 userService 没有 怎么 办? 实例化 就有了 */UserService userService new UserServiceImpl();User u userService.userLogin(username, password);//u可能为前面传递过来的user或是nullif(u null){response.getWriter().write(您的用户名或密码有误请检查);response.setHeader(Refresh, 5;Url request.getContextPath());}else{request.setAttribute(mark, 用户登录成功);request.getRequestDispatcher(/message.jsp).forward(request, response);}}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet( request, response);}} register.jsp % page languagejava importjava.util.* pageEncodingutf-8%
%
String path request.getContextPath();
String basePath request.getScheme()://request.getServerName():request.getServerPort()path/;
%!DOCTYPE HTML PUBLIC -//W3C//DTD HTML 4.01 Transitional//EN
htmlheadbase href%basePath%title注册/title/headbodycenterform action%basePath%servlet/UserRegistServlet methodpost table border1px width438px tr aligncentertd colspan2a href%basePath%login.jsp如已有用户点击去登录/a/td/trtr aligncentertd用户名/tdtdinput typetext nameusername /td/trtr aligncentertd密码/tdtdinput typepassword namepassword /td/trtr aligncentertd性别/tdtd男input typeradio namesex value男 checkedchecked 女input typeradio namesex value女 /td/trtr aligncentertd colspan2 input typesubmit value免费注册 input typereset value重置内容 /td/tr/table /form/center/body
/html转载于:https://www.cnblogs.com/xiaoxiao5016/p/10598999.html
