02尚硅谷书城案例-用户的注册

1、JavaEE 项目的三层架构

2、先创建书城需要的数据库和表

drop database if exists book;

create database book;

CREATE TABLE t_user(
id INT PRIMARY KEY auto_increment,
username VARCHAR(20) NOT NULL UNIQUE,
PASSWORD VARCHAR(32) NOT NULL,
email VARCHAR(200)
);

insert into t_user(username,password,email) values(‘admin’,‘admin’,‘admin@aiguigu.com’);
select * from t_user;

3、编写数据库表对应的 JavaBean 对象

public class User {private Integer id;private String username;private String password;private String email;
}

4、编写工具类 JdbcUtils

4.1、导入需要的 jar包（数据库和连接池需要）

导入完成之后：

4.2 在 src 源码目录编写 jdbc.properties 属性配置文件

4.3 编写 JdbcUtils 工具类

package com.utils;import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.pool.DruidDataSourceFactory;import java.io.InputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;public class JdbcUtils {private static DruidDataSource dataSource;static {try {Properties  properties = new Properties();//读取 jdbc.properties 属性配置文件InputStream inputStream = JdbcUtils.class.getClassLoader().getResourceAsStream("jdbc.properties");//从流中加载数据properties.load(inputStream);//创建 数据库 连接池dataSource = (DruidDataSource) DruidDataSourceFactory.createDataSource(properties);} catch (Exception e) {e.printStackTrace();}}/** 获取数据库连接池中的连接*@return 如果返回null，说明获取连接失败<br/>有值就是获取连接成功 */public static Connection getConnection(){Connection conn = null;try {conn = dataSource.getConnection();} catch (SQLException e) {e.printStackTrace();}return conn;}/** 关闭连接，放回数据库连接池* */public static void close(Connection conn){if (conn != null){try {conn.close();} catch (SQLException e) {e.printStackTrace();}}}
}

4.4、Jdbc测试

package com.aiguigu.test;import com.utils.JdbcUtils;
import org.junit.Test;import java.sql.Connection;public class JdbcUtilsTest {@Testpublic void testJdbcUtils(){for (int i = 0; i < 100; i++) {Connection connection = JdbcUtils.getConnection();System.out.println(connection);JdbcUtils.close(connection);}}
}

5、编写BaseDao（这一块不懂，得补）

package com.aiguigu.dao;import com.utils.JdbcUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;import java.awt.*;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;public abstract class BaseDao {//使用DbUtils 操作数据库private QueryRunner queryRunner = new QueryRunner();/*** update() 方法用来执行：Insert\Update\Delete* @return 如果返回 -1 ，说明执行失败<br/>返回其他表示影响的行数*/public int update(String sql,Object ... args){Connection connection = JdbcUtils.getConnection();try {queryRunner.update(connection,sql,args);} catch (SQLException e) {e.printStackTrace();}finally {JdbcUtils.close(connection);}return -1;}/*** 查询返回一个 javaBean 的 sql 语句* @param type 返回的对象类型* @param sql  执行的sql语句* @param args sql对应的参数值* @param <T>  返回的类型的泛型*/public <T> T queryForOne(Class<T> type,String sql,Object ... args){Connection con = JdbcUtils.getConnection();try {return queryRunner.query(con,sql,new BeanHandler<T>(type),args);} catch (SQLException e) {e.printStackTrace();}finally {JdbcUtils.close(con);}return null;}/*** 查询返回多个 javaBean 的 sql 语句* @param type 返回的对象类型* @param sql  执行的sql语句* @param args sql对应的参数值* @param <T>  返回的类型的泛型*/public <T> List<T>  queryForList(Class<T> type, String sql, Object ... args){Connection con = JdbcUtils.getConnection();try {return queryRunner.query(con,sql,new BeanListHandler<T>(type),args);} catch (SQLException e) {e.printStackTrace();}finally {JdbcUtils.close(con);}return null;}/*** 执行返回一行一列的sql语句* @param sql 执行的sql语句* @param args sql对应的参数值*/public Object queryForSingleValue(String sql,Object ... args){Connection conn = JdbcUtils.getConnection();try {return queryRunner.query(conn,sql,new ScalarHandler(),args);} catch (SQLException e) {e.printStackTrace();} finally {JdbcUtils.close(conn);}return null;}}

6、编写UserDao 和测试

package com.aiguigu.dao;import com.aiguigu.pojo.User;public interface UserDao {/*** 根据用户名查询用户信息* @param username 用户名* @return 如果返回null,说明没有这个用户，反之亦然*/public User queryUserByUsername(String username);/*** 根据用户名和密码查询用户信息* @param username 用户名* @param password 密码* @return 如果返回null,说明没用户名或密码错误，反之亦然*/public User queryUserByUsernameAndPassword(String username,String password);/*** 保存用户信息* @param user* @return 返回-1表示操作失败，其他sql语句影响的行数*/public int saveUser(User user);}

package com.aiguigu.dao.impl;import com.aiguigu.dao.BaseDao;
import com.aiguigu.dao.UserDao;
import com.aiguigu.pojo.User;public class UserDaoImpl extends BaseDao implements UserDao {@Overridepublic User queryUserByUsername(String username) {String sql = "select `id`,`username`,`password`,`email` from t_user where username=?";return queryForOne(User.class,sql,username);}@Overridepublic User queryUserByUsernameAndPassword(String username, String password) {String sql = "select `id`,`username`,`password`,`email` from t_user where username=? and password=?";return queryForOne(User.class,sql,username,password);}@Overridepublic int saveUser(User user) {String sql = "insert into t_user(`username`,`password`,`email`) values(?,?,?)";return update(sql,user.getUsername(),user.getPassword(),user.getEmail());}
}

package com.aiguigu.dao.impl;import com.aiguigu.pojo.User;
import org.junit.Test;import static org.junit.Assert.*;public class UserDaoImplTest {@Testpublic void queryUserByUsername() {UserDaoImpl userDao = new UserDaoImpl();if (userDao.queryUserByUsername("admin") == null){System.out.println("用户名可用");}else {System.out.println("用户名已存在");}}@Testpublic void queryUserByUsernameAndPassword() {UserDaoImpl userDao = new UserDaoImpl();if (userDao.queryUserByUsernameAndPassword("admin","admin") == null){System.out.println("用户名或密码错误，登录失败");}else {System.out.println("查询成功");}}@Testpublic void saveUser() {UserDaoImpl userDao = new UserDaoImpl();System.out.println( userDao.saveUser(new User(null,"qweg168", "12qw6", "qwe168@qq.com")) );}
}

编写UserService 和测试

UserService接口：

package com.aiguigu.service;import com.aiguigu.pojo.User;public interface UserService {/*** 注册用户* @param  user* */public void registUser(User user);/*** 登录* @param user* @return 如果返回 null,说明登录失败，返回有值，是登录 成功*/public User login(User user);/*** 检查 用户名是否可用* @param username* @return 返回true表示用户名已存在，返回false表示用户名可用*/public boolean existUsername(String username);
}

UserServiceImpl：

package com.aiguigu.service.impl;import com.aiguigu.dao.UserDao;
import com.aiguigu.dao.impl.UserDaoImpl;
import com.aiguigu.pojo.User;
import com.aiguigu.service.UserService;
import com.aiguigu.test.UserDaoImplTest;public class UserServiceImpl implements UserService {private UserDao useDao = new UserDaoImpl();@Overridepublic void registUser(User user) {useDao.saveUser(user);}@Overridepublic User login(User user) {return useDao.queryUserByUsernameAndPassword(user.getUsername(),user.getPassword());}@Overridepublic boolean existUsername(String username) {if (useDao.queryUserByUsername(username) == null){// 等于null，说明没查到，没查到表示可用return false;}return true;}
}

UserServiceImplTest：

package com.aiguigu.test;import com.aiguigu.dao.impl.UserDaoImpl;
import com.aiguigu.pojo.User;
import com.aiguigu.service.UserService;
import com.aiguigu.service.impl.UserServiceImpl;
import org.junit.Test;import static org.junit.Assert.*;public class UserServiceImplTest {UserService userService = new UserServiceImpl();@Testpublic void registUser() {userService.registUser(new User(null,"qwe1234","qwe123",null));}@Testpublic void login() {System.out.println(userService.login(new  User(null,"qwe1234","qwe1235",null)));}@Testpublic void existUsername() {if (userService.existUsername("qwe1234")){System.out.println("用户名已存在！");}else {System.out.println("用户名可用！");}}}

7、编写 web 层

7.1、实现用户注册的功能

分析：

编写 RegistServlet：

package com.aiguigu.web;import com.aiguigu.dao.UserDao;
import com.aiguigu.pojo.User;
import com.aiguigu.service.UserService;
import com.aiguigu.service.impl.UserServiceImpl;import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;public class RegistServlet extends HttpServlet {UserService userService = new UserServiceImpl();@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//1.获取请求参数String username = req.getParameter("username");String password = req.getParameter("password");String email = req.getParameter("email");String code = req.getParameter("code");//2.检查 验证码是否正确   写死，要求验证码为：abcdeif ("abcde".equalsIgnoreCase(code)){//equalsIgnoreCase:比较时忽略大小写//正确//3.检查 用户名是否可用if (userService.existUsername(username)){//不可用System.out.println("用户名[" + username + "]已存在");//跳回注册页面req.getRequestDispatcher("/pages/user/regist.html").forward(req,resp);}else {//可用//调用Service 保存到数据库userService.registUser(new User(null,username,password,email));//跳到注册成功页面 regist_success.htmlreq.getRequestDispatcher("/pages/user/regist_success.html").forward(req,resp);}}else {System.out.println("验证码["+ code + "]错误");req.getRequestDispatcher("/pages/user/regist.html").forward(req,resp);}}
}

在前端的 regist.html 页面加上 base相对路径

 <!--写 base 标签，永远固定相对路径跳转  的结果--><base href="http://localhost:8080/book/">

修改 regist.html 里面的资源路径：

在页面运行按 F12 通过网络来测试，有 报红的 都要修改路径

修改注册表单的提交路径并添加 post 方法将表单信息发送给 servlet服务器：

验证码输入框添加一个 name属性便于服务器获取（这个以后优化）：

后端接收参数：

对接收到的参数进行以下操作：

 //2.检查 验证码是否正确   写死，要求验证码为：abcdeif ("abcde".equalsIgnoreCase(code)){//equalsIgnoreCase:比较时忽略大小写//正确//3.检查 用户名是否可用if (userService.existUsername(username)){//不可用System.out.println("用户名[" + username + "]已存在");//跳回注册页面req.getRequestDispatcher("/pages/user/regist.html").forward(req,resp);}else {//可用//调用Service 保存到数据库userService.registUser(new User(null,username,password,email));//跳到注册成功页面 regist_success.htmlreq.getRequestDispatcher("/pages/user/regist_success.html").forward(req,resp);}}else {System.out.println("验证码["+ code + "]错误");req.getRequestDispatcher("/pages/user/regist.html").forward(req,resp);}

到 regist,html 进行测试