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[JavaScript知识库]Java全栈（四）web网页技术：9.书城项目实战一：jQuery和Servlet练习

一.项目介绍

1.项目页面原型下载

书城项目页面原型可以直接从gitee上下载：https://gitee.com/ouyi19940129/BookStore.git

2.项目页面原型目录讲解

在这里插入图片描述

二.阶段1：jQuery实战

1.需求：

在这里插入图片描述

2.实现：

（1）使用IDEA创建web项目

先创建一个普通java项目
在该项目中引入web

classes用于存放编译后的文件，lib存放第三方jar包

在这里插入图片描述

（2）使用jQuery实现登录页面的用户名密码非空校验

在pages/user/login.html中引入jquery-1.7.2.js和login.js

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <title>尚硅谷会员登录页面</title>
    <link type="text/css" rel="stylesheet" href="../../static/css/style.css" />
    <script type="text/javascript" src="../../static/script/jquery-1.7.2.js"></script>
    <script type="text/javascript" src="../../static/script/login.js"></script>
  </head>
  <body>
    <div id="login_header">
      <a href="../../index.html">
        <img class="logo_img" alt="" src="../../static/img/logo.gif" />
      </a>
    </div>

    <div class="login_banner">
      <div id="l_content">
        <span class="login_word">欢迎登录</span>
      </div>

      <div id="content">
        <div class="login_form">
          <div class="login_box">
            <div class="tit">
              <h1>尚硅谷会员</h1>
            </div>
            <div class="msg_cont">
              <b></b>
              <span class="errorMsg">请输入用户名和密码</span>
            </div>
            <div class="form">
              <form action="login_success.html">
                <label>用户名称：</label>
                <input
                  class="itxt"
                  type="text"
                  placeholder="请输入用户名"
                  autocomplete="off"
                  tabindex="1"
                  name="username"
                  id="username"
                />
                <br />
                <br />
                <label>用户密码：</label>
                <input
                  class="itxt"
                  type="password"
                  placeholder="请输入密码"
                  autocomplete="off"
                  tabindex="1"
                  name="password"
                  id="password"
                />
                <br />
                <br />
                <input type="submit" value="登录" id="sub_btn" />
              </form>
              <div class="tit">
                <a id = "submit" href="regist.html">立即注册</a>
              </div>
            </div>
          </div>
        </div>
      </div>
    </div>
    <div id="bottom">
      <span>
        尚硅谷书城.Copyright &copy;2015
      </span>
    </div>
  </body>
</html>

在static/script/目录下创建login.js文件

$(function () {
    /**
     * 检查用户名函数
     */
    function checkUsernamePassword() {
        var username = $("#username").val();
        var password = $("#password").val();
        if (username == "" || password == "") {
            alert("用户名密码不能为空");
            return false;
        }
    }

    /**
     * 点击登录按钮事件函数
     */
    $("#sub_btn").click(checkUsernamePassword);
})

（3）使用jQuery实现注册页面校验

在pages\user\regist.html文件中引入jquery-1.7.2.js和regist.js文件

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <title>尚硅谷会员注册页面</title>
    <link type="text/css" rel="stylesheet" href="../../static/css/style.css" />
    <link rel="stylesheet" href="../../static/css/register.css" />
    <style type="text/css">
      .login_form {
        height: 420px;
        margin-top: 25px;
      }
    </style>
    <script type="text/javascript" src="../../static/script/jquery-1.7.2.js"></script>
    <script type="text/javascript" src="../../static/script/regist.js"></script>
  </head>
  <body>
    <div id="login_header">
      <a href="../../index.html">
        <img class="logo_img" alt="" src="../../static/img/logo.gif" />
      </a>
    </div>

    <div class="login_banner">
      <div class="register_form">
        <h1>注册尚硅谷会员</h1>
        <form action="regist_success.html">
          <div class="form-item">
            <div>
              <label>用户名称:</label>
              <input id="username" type="text" placeholder="请输入用户名"/>
            </div>
            <span class="errMess" id="userErrMess">用户名、密码：只能是字母（大小写）、数字、_。6-18位</span>
          </div>
          <div class="form-item">
            <div>
              <label>用户密码:</label>
              <input type="password" id="password" placeholder="请输入密码" />
            </div>
            <span class="errMess" id="passErrMess">只能是字母（大小写）、数字、_。6-18位</span>
          </div>
          <div class="form-item">
            <div>
              <label>确认密码:</label>
              <input type="password" id="rePassword" placeholder="请输入确认密码" />
            </div>
            <span class="errMess" id="rePasswordErrMess">密码两次输入不一致</span>
          </div>
          <div class="form-item">
            <div>
              <label>用户邮箱:</label>
              <input type="text" id="email" placeholder="请输入邮箱" />
            </div>
            <span class="errMess" id="emailErrMess">请输入正确的邮箱格式</span>
          </div>
          <div class="form-item">
            <div>
              <label>验证码:</label>
              <div class="verify">
                <input type="text" id="verify" placeholder="" />
                <img src="../../static/img/code.bmp" alt="" />
              </div>
            </div>
            <span class="errMess" id="verifyErrMess">请输入正确的验证码</span>
          </div>
          <button class="btn" id="register">注册</button>
        </form>
      </div>
    </div>
    <div id="bottom">
      <span>
        尚硅谷书城.Copyright &copy;2015
      </span>
    </div>
  </body>
</html>

在static/script/regist.js文件中实现注册用户输入参数的校验

$(function () {

    /**
     * 用户名校验
     */
    function checkUsername() {
        var reg = /^[a-zA-Z0-9_]{6,18}$/;
        var userVaule = $("#username").val();
        if (reg.test(userVaule) == false) {
            $("#userErrMess").css("visibility", "visible");
            return false;
        } else {
            $("#userErrMess").css("visibility", "hidden");
        }
    }

    /**
     * 密码校验
     */
    function checkPassword() {
        var reg = /^[a-zA-Z0-9_]{6,18}$/;
        var passwordValue = $("#password").val();
        if (reg.test(passwordValue) == false) {
            $("#passErrMess").css("visibility", "visible");
            return false;
        } else {
            $("#passErrMess").css("visibility", "hidden");
        }
    }


    /**
     * 确认密码
     */
    function checkrePassword() {
        var passwordValue = $("#password").val();
        var rePasswordValue = $("#rePassword").val();
        if (passwordValue != rePasswordValue) {
            $("#rePasswordErrMess").css("visibility", "visible");
            return false;
        } else {
            $("#rePasswordErrMess").css("visibility", "hidden");
        }
    }

    /**
     * 检查邮箱
     */
    function checkEmail(){
        var reg = /^([a-z0-9_\.-]+)@([\da-z\.-]+)\.([a-z\.]{2,6})$/;
        var emailValue = $("#email").val();
        if (reg.test(emailValue) == false){
            $("#emailErrMess").css("visibility", "visible");
            return false;
        }else {
            $("#emailErrMess").css("visibility", "hidden");
        }
    }

    function checkVerify(){
        var verifyValue = $("#verify").val();
        if (verifyValue == ""){
            $("#verifyErrMess").css("visibility", "visible");
            return false;
        }else {
            $("#verifyErrMess").css("visibility", "hidden");
        }
    }

    // 注册栏内容改变后校验
    $("#username").change(checkUsername);
    $("#password").change(checkPassword);
    $("#rePassword").change(checkrePassword);
    $("#email").change(checkEmail);
    $("#verify").change(checkVerify);

    // 注册按钮后校验
    $("#register").click(checkUsername);
    $("#register").click(checkPassword);
    $("#register").click(checkrePassword);
    $("#register").click(checkEmail);
    $("#register").click(checkVerify);
})

三.阶段2：Servlet实战

1.需求：

实现用户的登录和注册功能。

登录成功重定向到登录成功页面，登录失败则转发到登录页面
注册成功重定向到注册成功页面，注册失败则转发到注册页面

2.原理：

使用三层模型来实现。
在这里插入图片描述

在这里插入图片描述

3.实现：

（0）项目依赖引入

引入Tomcat服务器
引入Servlet
第一步： RUN》Edit Configurations》

第二步：在当前项目的iml文件中引入tomcat

第三步：重启idea

第四步：引入Facets

（1）HTML页面

修改以下几个与登录注册相关的页面，①使用base标签完成绝对路径的修改；②点击登录按钮将用户名密码提交到LoginServlet中验证；③点击注册按钮将用户名、密码、邮箱提交到RegisterServlet中验证
在这里插入图片描述

<!DOCTYPE html>
<html>
  <head>
    <base href="http://localhost:8080/bookStoreTest1/"/>
    <meta charset="UTF-8" />
    <title>尚硅谷会员登录页面</title>
    <link type="text/css" rel="stylesheet" href="static/css/style.css" />
    <script type="text/javascript" src="static/script/jquery-1.7.2.js"></script>
    <script type="text/javascript" src="static/script/login.js"></script>
  </head>
  <body>
    <div id="login_header">
      <a href="index.html">
        <img class="logo_img" alt="" src="static/img/logo.gif" />
      </a>
    </div>

    <div class="login_banner">
      <div id="l_content">
        <span class="login_word">欢迎登录</span>
      </div>

      <div id="content">
        <div class="login_form">
          <div class="login_box">
            <div class="tit">
              <h1>尚硅谷会员</h1>
            </div>
            <div class="msg_cont">
              <b></b>
              <span class="errorMsg">请输入用户名和密码</span>
            </div>
            <div class="form">
              <!--跳转到login对应的Servlet中-->
              <form action="login">
                <label>用户名称：</label>
                <input
                  class="itxt"
                  type="text"
                  placeholder="请输入用户名"
                  autocomplete="off"
                  tabindex="1"
                  name="username"
                  id="username"
                />
                <br />
                <br />
                <label>用户密码：</label>
                <input
                  class="itxt"
                  type="password"
                  placeholder="请输入密码"
                  autocomplete="off"
                  tabindex="1"
                  name="password"
                  id="password"
                />
                <br />
                <br />
                <input type="submit" value="登录" id="sub_btn" />
              </form>
              <div class="tit">
                <a id = "submit" href="regist.html">立即注册</a>
              </div>
            </div>
          </div>
        </div>
      </div>
    </div>
    <div id="bottom">
      <span>
        尚硅谷书城.Copyright &copy;2015
      </span>
    </div>
  </body>
</html>

login_success.html

<!DOCTYPE html>
<html>
<head>
<base href="http://localhost:8080/bookStoreTest1/"/>
<meta charset="UTF-8">
<title>尚硅谷会员注册页面</title>
<link type="text/css" rel="stylesheet" href="static/css/style.css" >
<style type="text/css">
	h1 {
		text-align: center;
		margin-top: 200px;
	}
	
	h1 a {
		color:red;
	}
</style>
</head>
<body>
		<div id="header">
				<a href="index.html">
					<img class="logo_img" alt="" src="static/img/logo.gif" />
				</a>
				<div>
					<span>欢迎<span class="um_span">张总</span>光临尚硅谷书城</span>
					<a href="pages/order/order.html">我的订单</a>
					<a href="index.html">注销</a>&nbsp;&nbsp;
					<a href="index.html">返回</a>
				</div>
		</div>
		
		<div id="main">
		
			<h1>欢迎回来 <a href="index.html">转到主页</a></h1>
	
		</div>
		
		<div id="bottom">
			<span>
				尚硅谷书城.Copyright &copy;2015
			</span>
		</div>
</body>
</html>

<!DOCTYPE html>
<html>
  <head>
    <base href="http://localhost:8080/bookStoreTest1/"/>
    <meta charset="UTF-8" />
    <title>尚硅谷会员注册页面</title>
    <link type="text/css" rel="stylesheet" href="static/css/style.css" />
    <link rel="stylesheet" href="static/css/register.css" />
    <style type="text/css">
      .login_form {
        height: 420px;
        margin-top: 25px;
      }
    </style>
    <script type="text/javascript" src="static/script/jquery-1.7.2.js"></script>
    <script type="text/javascript" src="static/script/regist.js"></script>
  </head>
  <body>
    <div id="login_header">
      <a href="index.html">
        <img class="logo_img" alt="" src="static/img/logo.gif" />
      </a>
    </div>

    <div class="login_banner">
      <div class="register_form">
        <h1>注册尚硅谷会员</h1>
        <!--跳转到register对应的Servlet-->
        <form action="register">
          <div class="form-item">
            <div>
              <label>用户名称:</label>
              <input id="username" type="text" name="username" placeholder="请输入用户名"/>
            </div>
            <span class="errMess" id="userErrMess">用户名、密码：只能是字母（大小写）、数字、_。6-18位</span>
          </div>
          <div class="form-item">
            <div>
              <label>用户密码:</label>
              <input type="password" id="password" name="password" placeholder="请输入密码" />
            </div>
            <span class="errMess" id="passErrMess">只能是字母（大小写）、数字、_。6-18位</span>
          </div>
          <div class="form-item">
            <div>
              <label>确认密码:</label>
              <input type="password" id="rePassword" name="rePassword" placeholder="请输入确认密码" />
            </div>
            <span class="errMess" id="rePasswordErrMess">密码两次输入不一致</span>
          </div>
          <div class="form-item">
            <div>
              <label>用户邮箱:</label>
              <input type="text" id="email" name="email" placeholder="请输入邮箱" />
            </div>
            <span class="errMess" id="emailErrMess">请输入正确的邮箱格式</span>
          </div>
          <div class="form-item">
            <div>
              <label>验证码:</label>
              <div class="verify">
                <input type="text" id="verify" placeholder="" />
                <img src="static/img/code.bmp" alt="" />
              </div>
            </div>
            <span class="errMess" id="verifyErrMess">请输入正确的验证码</span>
          </div>
          <button class="btn" id="register">注册</button>
        </form>
      </div>
    </div>
    <div id="bottom">
      <span>
        尚硅谷书城.Copyright &copy;2015
      </span>
    </div>
  </body>
</html>

register_success.html

<!DOCTYPE html>
<html>
<head>
<base href="http://localhost:8080/bookStoreTest1/"/>
<meta charset="UTF-8">
<title>尚硅谷会员注册页面</title>
<link type="text/css" rel="stylesheet" href="static/css/style.css" >
<style type="text/css">
	h1 {
		text-align: center;
		margin-top: 200px;
	}
	
	h1 a {
		color:red;
	}
</style>
</head>
<body>
		<div id="header">
				<a href="index.html">
					<img class="logo_img" alt="" src="static/img/logo.gif" />
				</a>
				<span class="wel_word"></span>
				<div>
					<span>欢迎<span class="um_span">张总</span>光临尚硅谷书城</span>
					<a href="pages/order/order.html">我的订单</a>
					<a href="index.html">注销</a>&nbsp;&nbsp;
					<a href="index.html">返回</a>
				</div>
		</div>
		
		<div id="main">
		
			<h1>注册成功! <a href="index.html">转到主页</a></h1>
	
		</div>
		
		<div id="bottom">
			<span>
				尚硅谷书城.Copyright &copy;2015
			</span>
		</div>
</body>
</html>

（2）bean

在src目录下创建com.bookstore.bean目录，用于存放数据库的模型类，并创建User类。
在这里插入图片描述

package com.bookstore.bean;

/**
 * 用户类
 */
public class User {
    private Integer id; // 推荐使用包装类，更利于类型转化
    private String username;
    private String password;
    private String email;

    public User(Integer id, String username, String password, String email) {
        this.id = id;
        this.username = username;
        this.password = password;
        this.email = email;
    }

    public User() {
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                ", email='" + email + '\'' +
                '}';
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}

（3）Dao

在Dao层我们应该将对数据库的操作封装好。

（创建如下目录：

在这里插入图片描述

（导入jdbc相关的第三方软件

在这里插入图片描述

（在utils目录下，创建文件`JDBCUtils .java`用于封装数据库的连接，释放

在这里插入图片描述

package com.bookstore.utils;

import com.alibaba.druid.pool.DruidDataSourceFactory;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;

/**
 * 获取连接和释放连接的工具类
 * @author Chunsheng Zhang
 *
 */
public class JDBCUtils {
	private static DataSource dataSource;
	
	static {
		try {
			//1、读取druip.properties文件
			Properties pro = new Properties();
			pro.load(JDBCUtils.class.getClassLoader().getResourceAsStream("druid.properties"));
			
			//2、连接连接池
			dataSource = DruidDataSourceFactory.createDataSource(pro);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	//获取连接
	public static Connection getConnection() {
		Connection connection = null;
		try {
			connection = dataSource.getConnection();
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return connection;
	}

	//释放连接
	public static void releaseConnection(Connection connection) {
		if(connection != null) {
			try {
				connection.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}
}

（在dao目录下创建如下文件：

在这里插入图片描述

BaseDao.java

package com.bookstore.dao;

import com.bookstore.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.sql.Connection;
import java.sql.SQLException;
import java.util.List;

/**
 * 定义一个用来被继承的对数据库进行基本操作的Dao
 *
 * @param <T>
 * @author Chunsheng Zhang
 */
public class BaseDao<T> {
    private QueryRunner queryRunner = new QueryRunner();
    public BaseDao() {
    }

    /**
     * 通用的增删改操作
     * sql: insert delete update
     *
     * @param sql
     * @param params
     * @return
     */
    public int update(String sql, Object... params) {
        // 获取连接
        Connection connection = JDBCUtils.getConnection();
        int count = 0;
        try {
            count = queryRunner.update(connection, sql, params);
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JDBCUtils.releaseConnection(connection);
        }
        return count;
    }

    /**
     * 获取一个对象
     *
     * @param sql
     * @param params
     * @return
     */
    public T getBean(Class<T> clazz, String sql, Object... params) {
        // 获取连接
        Connection connection = JDBCUtils.getConnection();
        T t = null;
        try {
            t = queryRunner.query(connection, sql, new BeanHandler<T>(clazz),
                    params);
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JDBCUtils.releaseConnection(connection);
        }
        return t;
    }

    /**
     * 获取所有对象
     *
     * @param sql
     * @param params
     * @return
     */
    public List<T> getBeanList(Class<T> clazz, String sql, Object... params) {
        // 获取连接
        Connection connection = JDBCUtils.getConnection();
        List<T> list = null;
        try {
            list = queryRunner.query(connection, sql, new BeanListHandler<T>(
                    clazz), params);
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JDBCUtils.releaseConnection(connection);
        }
        return list;
    }


    /**
     * 获取单个数值的通用方法
     */
    public Object getSingleValue(String sql, Object... params) {
        // 获取连接
        Connection connection = JDBCUtils.getConnection();
        Object o = null;
        try {
            o = queryRunner.query(connection, sql, new ScalarHandler<>(),
                    params);
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JDBCUtils.releaseConnection(connection);
        }
        return o;
    }
}

UserDao接口

package com.bookstore.dao;

import com.bookstore.bean.User;

import java.util.List;

/**
 *
 * sql: SELECT * FROM users WHERE(username="?" AND password="?");
 */
public interface UserDao {
    /**
     * 根据用户名密码查询单个用户。sql: SELECT * FROM users WHERE(username="?" AND password="?");
     * @param user: 当sql中有多个参数需要赋值时，推荐传入bean对象
     * @return
     */
    public User getUserByUsernamePwd(User user);

    /**
     * 根据用户名查询多个用户。sql: SELECT * FROM users WHERE(username="?");
     * @param username: 当sql中只有一个参数值需要赋值时，可以不用封装为对象
     * @return
     */
    public List<User> getUserByUsername(String username);

    /**
     * 将User对象储存到数据库中。sql=“INSERT INTO users(username,`password`,email)  VALUES(?,?,?);”
     * @param user
     * @return
     */
    public int saveUser(User user);
}

UserDaoImpl.java

package com.bookstore.dao.impl;

import com.bookstore.bean.User;
import com.bookstore.dao.BaseDao;
import com.bookstore.dao.UserDao;

import java.util.List;

public class UserDaoImll extends BaseDao<User> implements UserDao {

    /**
     * 根据用户名密码查询单个用户
     *
     * @param user: 当sql中有多个参数需要赋值时，推荐传入bean对象
     * @return
     */
    @Override
    public User getUserByUsernamePwd(User user) {
        String sql = "SELECT * FROM users WHERE(username=? AND password=?)";
        return getBean(User.class, sql, user.getUsername(), user.getPassword());
    }

    /**
     * 根据用户名查询多个用户
     *
     * @param username
     * @return
     */
    @Override
    public List<User> getUserByUsername(String username) {
        String sql = "SELECT * FROM users WHERE(username=?)";
        return getBeanList(User.class, sql, username);
    }

    /**
     * 储存User对象到数据库中
     *
     * @param user
     * @return
     */
    @Override
    public int saveUser(User user) {
        String sql = "INSERT INTO users(username,`password`,email)  VALUES(?,?,?)";
        return update(sql, user.getUsername(), user.getPassword(), user.getEmail());
    }
}

（4）service

在service目录下可以封装业务逻辑的代码
在这里插入图片描述

UserServices接口

package com.bookstore.service;

import com.bookstore.bean.User;

/**
 * 处理用户相关业务逻辑
 */
public interface UserServices {
    /**
     * 处理用户登录相关业务。
     *
     * @param user
     */
    User login(User user);

    /**
     * 处理用户注册的方法
     *
     * @param user
     * @return
     */
    boolean regist(User user);
}

UserServicesImpl.java

package com.bookstore.service.impl;

import com.bookstore.bean.User;
import com.bookstore.dao.impl.UserDaoImll;
import com.bookstore.service.UserServices;

import java.util.List;

public class UserservicesImpl extends UserDaoImll implements UserServices {

    /**
     * 处理用户登录业务逻辑
     * @param user
     * @return
     */
    @Override
    public User login(User user) {
        User userRes = getUserByUsernamePwd(user);
        if (userRes == null){
            return null;
        }else {
            return userRes;
        }
    }

    @Override
    public boolean regist(User user) {
        List<User> users = getUserByUsername(user.getUsername());
        if (users.size() > 0){
            return false;
        }else {
            int i = saveUser(user);
            if (i>=1){
                return true;
            }
            return false;
        }
    }
}

（5）Servlet

在这里插入图片描述

LoginServlet.java

package com.bookstore.servlet;

import com.bookstore.bean.User;
import com.bookstore.service.UserServices;
import com.bookstore.service.impl.UserservicesImpl;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet(name = "LoginServlet", value = "/login")
public class LoginServlet extends HttpServlet {
    private UserServices userservices = new UserservicesImpl();

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //获取用户名,密码
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        // 检查用户名密码是否正确
        User userOld = new User();
        userOld.setUsername(username);
        userOld.setPassword(password);
        User loginUser = userservices.login(userOld);
        if (loginUser != null) {
            // 用户名密码正确
            response.sendRedirect("/bookStoreTest1/pages/user/login_success.html");
        } else {
            // 用户名密码不正确
            request.getRequestDispatcher("/pages/user/login.html").forward(request, response);
        }


    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }
}

RegisterServlet.java\

package com.bookstore.servlet;

import com.bookstore.bean.User;
import com.bookstore.service.impl.UserservicesImpl;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet(name = "RegisteServlet", value = "/register")
public class RegisteServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String email = request.getParameter("email");
        User user = new User(null,username,password,email);
        UserservicesImpl userservices = new UserservicesImpl();
        boolean registFag = userservices.regist(user);
        if (registFag){
            response.sendRedirect("/bookStoreTest1/pages/user/regist_success.html");
        }else {
            request.getRequestDispatcher("/pages/user/regist.html").forward(request,response);
        }
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request,response);
    }
}