JavaWeb實(shí)現(xiàn)用戶登錄與注冊功能(服務(wù)器)

更新時(shí)間：2021年09月10日 11:43:41 作者：奈何橋下的一道光線√

這篇文章主要介紹了JavaWeb實(shí)現(xiàn)用戶登錄與注冊功能，服務(wù)器部分的關(guān)鍵代碼實(shí)現(xiàn)，文中示例代碼介紹的非常詳細(xì)，具有一定的參考價(jià)值，感興趣的小伙伴們可以參考一下

本文實(shí)例為大家分享了JavaWeb實(shí)現(xiàn)用戶登錄與注冊功能的具體代碼，供大家參考，具體內(nèi)容如下

用到的知識

客戶端：HTML CSS JS （JQuery）

服務(wù)器：JAVA基礎(chǔ) JSP Servlet JDBC Tomcat

數(shù)據(jù)庫：MySQL

用到的Jar包 druid數(shù)據(jù)庫連接池 dbutils JDBC數(shù)據(jù)庫操作工具 MySQL jar包

總體結(jié)構(gòu)：

客戶端數(shù)據(jù)庫部分網(wǎng)址

思路：

服務(wù)器部分采用JavaEE三層架構(gòu)

(1)、表現(xiàn)層：通俗講就是展現(xiàn)給用戶的界面，即用戶在使用一個(gè)系統(tǒng)的時(shí)候他的所見所得。
(2)、業(yè)務(wù)邏輯層：針對具體問題的操作，也可以說是對數(shù)據(jù)層的操作，對數(shù)據(jù)業(yè)務(wù)邏輯處理。
(3)、數(shù)據(jù)訪問層：該層所做事務(wù)直接操作數(shù)據(jù)庫，針對數(shù)據(jù)的增添、刪除、修改、查找等。

先創(chuàng)建基本的文件夾架構(gòu)，三層的文件夾依次為web ，servlet ，DAO。此外還有其他相關(guān)文件夾工具類utils，JAVABean類pojo，測試類test 。依次實(shí)現(xiàn)從DAO層到Servce層再到Web層。

文件夾架構(gòu)

資源文件 jdbc.properties

username=root
password=123456
url=jdbc:mysql://localhost:3306/book
driverClassName=com.mysql.jdbc.Driver
initialSize=5
maxActive=10

一、DAO層

0.寫好JAVABean User類

package com.book.pojo;
 
public class User {
    private Integer id;
    private String username;
    private String password;
    private String email;
 
    public User() {
    }
 
    public User(Integer id, String username, String password, String email) {
        this.id = id;
        this.username = username;
        this.password = password;
        this.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;
    }
 
    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                ", email='" + email + '\'' +
                '}';
    }
 
}

1.先實(shí)現(xiàn)數(shù)據(jù)連接

JDBCUtils

package com.book.utils;
 
import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.pool.DruidDataSourceFactory;
 
 
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;
 
public class JDBCUtils {
 
    private static DruidDataSource druidDataSource;
 
    //數(shù)據(jù)庫連接池初始化
    static {
        try {
 
            InputStream resourceAsStream = JDBCUtils.class.getClassLoader().getResourceAsStream("jdbc.properties");//類加載器默認(rèn)是從classPath路徑加載資源
            Properties properties = new Properties();
            properties.load(resourceAsStream);
            //創(chuàng)建數(shù)據(jù)庫連接池
            druidDataSource = (DruidDataSource) DruidDataSourceFactory.createDataSource(properties);
        } catch (Exception e) {
            System.out.println("數(shù)據(jù)庫連接池初始化異常");
        }
    }
 
    //獲取數(shù)據(jù)庫連接池中的連接
    public static Connection getConnection() {
 
        Connection connection= null;
        try {
            connection = druidDataSource.getConnection();
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }
        return connection;
 
    }
 
    public static void close(Connection connection) {
        try {
            connection.close();
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }
    }
 
    public static void main(String[] args) {
        JDBCUtils jdbcUtils=new JDBCUtils();
        System.out.println(jdbcUtils.getConnection());
    }
}

2.測試連接是否成功

3.編寫B(tài)aseDAO 實(shí)現(xiàn)對數(shù)據(jù)庫的基本通用操作

package com.book.DAO;
import com.book.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.ArrayList;
import java.util.List;
public abstract class BaseDAO {
    private QueryRunner queryRunner=new QueryRunner();
    //數(shù)據(jù)庫通用操作,使用dbutils來操作
    //用來執(zhí)行updata，delete，insert
    public int updata(String sql,Object...objects){
        Connection connection= JDBCUtils.getConnection();
        try {
            return queryRunner.update(connection,sql,objects);//返回影響的行數(shù)
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }
        return -1;
    }
    //用來執(zhí)行查詢操作
    public <T>T queryForOne(Class<T>clazz,String sql,Object...objects){
        Connection connection=JDBCUtils.getConnection();
        try {
            return queryRunner.query(connection,sql,new BeanHandler<T>(clazz),objects);
        } catch (Exception throwables) {
            throwables.printStackTrace();
        }
        return null;
    }
    //查詢多個(gè)結(jié)果
    public <T>List<T> queryForList(Class<T>clazz,String sql,Object...objects){
        Connection connection=JDBCUtils.getConnection();
        List<T>list=new ArrayList<>();
        try {
            list=queryRunner.query(connection,sql,new BeanListHandler<T>(clazz),objects);
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }
        return list;
    }
    //查詢單個(gè)數(shù)
    public Object queryForSingleValue(String sql,Object...objects){
        Connection connection= JDBCUtils.getConnection();
        try {
            return queryRunner.query(connection,sql,new ScalarHandler(),objects);
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }
        return null;
    }
}

4.編寫UserDAO接口確定需要的操作

package com.book.DAO;
 
import com.book.pojo.User;
public interface UserDAO {
    // 注冊時(shí)判斷是否該用戶名已經(jīng)被注冊  根據(jù)用戶名查詢用戶信息 如果返回null說明沒有該用戶
    public User queryUserByUsername(String username);
 
    //注冊成功   保存用戶信息
    public int saveUser(User user);
 
    //登錄操作 根據(jù)用戶名和密碼查詢用戶 查不到返回null
    public User queryUserByUsernameAndPassword(String username,String password);
}

5.UserDAOImpl實(shí)現(xiàn)UserDAO接口

package com.book.DAO;
import com.book.pojo.User;
//所犯錯(cuò)誤：繼承的子類會(huì)有父類的全部方法，不要在子類中聲明父類對象，調(diào)用父類方法
public class UserDAOimpl extends BaseDAO implements UserDAO{
 
    @Override
    public User queryUserByUsername(String username) {
        String sql="select * from users where username=?";
        User user =queryForOne(User.class,sql,username);
        return user;
    }
    //所犯錯(cuò)誤：輸入的郵箱不能重復(fù)
    @Override
    public int saveUser(User user) {
        String sql="INSERT INTO `users`(`username`,`password`,`email`) VALUES(?,?,?)";
        int n;
        n = updata(sql,user.getUsername(),user.getPassword(),user.getEmail());
        return n;
    }
    @Override
    public User queryUserByUsernameAndPassword(String username, String password) {
        String sql="select * from users where username=? and password=?";
        User user=queryForOne(User.class,sql,username,password);
        return user;
    }
}

二、Servlet層

1.UserServce接口確定業(yè)務(wù)需要的方法，用來與Web層進(jìn)行交互

package com.book.servlet;
import com.book.pojo.User;
//業(yè)務(wù)層一個(gè)業(yè)務(wù)一個(gè)方法
public interface UserServce {
    //注冊業(yè)務(wù) 注冊成功將用戶保存到數(shù)據(jù)庫中
    public void registUser(User user);
    //登錄業(yè)務(wù)
    public User login(User user);
    //檢查用戶名是否可用 返回true表示用戶名已存在
    public boolean existUsername(String username);
}

2.UserServceImpl類實(shí)現(xiàn)UserServce接口

package com.book.servlet;
import com.book.DAO.UserDAO;
import com.book.DAO.UserDAOimpl;
import com.book.pojo.User;
 
public class UserServceImpl implements UserServce {
 
    private UserDAO userDAO=new UserDAOimpl();
    @Override
    public void registUser(User user) {
        userDAO.saveUser(user);
    }
 
    @Override
    public User login(User user) {
       return userDAO.queryUserByUsernameAndPassword(user.getUsername(),user.getPassword());
    }
 
    @Override
    public boolean existUsername(String username) {
        //用戶名不存在
         if(userDAO.queryUserByUsername(username)==null){
             return false;
         }else {
             return true;
         }
    }
}

三、Web層

1.注冊操作

package com.book.web;
import com.book.pojo.User;
import com.book.servlet.UserServce;
import com.book.servlet.UserServceImpl;
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 {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        UserServce userServce=new UserServceImpl();
       //獲取請求參數(shù)
        String username=req.getParameter("username");
        String password=req.getParameter("password");
        String email=req.getParameter("email");
        String code=req.getParameter("code");
        //判斷驗(yàn)證碼是否正確 忽略大小寫
        if("6n6np".equalsIgnoreCase(code)){
            //判斷是否存在用戶名
            if(!userServce.existUsername(username)){
                //不存在則將注冊信息寫入數(shù)據(jù)庫
                User user=new User(null,username,password,email);
                userServce.registUser(user);
                //請求轉(zhuǎn)發(fā)到注冊成功頁面
                req.getRequestDispatcher("/pages/user/regist_success.jsp").forward(req,resp);
            }else{
                System.out.println("用戶名已存在");
                //跳轉(zhuǎn)到注冊頁面
                req.getRequestDispatcher("/pages/user/regist.jsp").forward(req,resp);
            }
        }else {
            System.out.println("驗(yàn)證碼錯(cuò)誤");
            //跳轉(zhuǎn)到注冊頁面
            req.getRequestDispatcher("/pages/user/login.jsp").forward(req,resp);
        }
    }
}

2.登錄操作

package com.book.web;
 
import com.book.pojo.User;
import com.book.servlet.UserServce;
import com.book.servlet.UserServceImpl;
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 LoginServlet extends HttpServlet {
    private UserServce userServce=new UserServceImpl();
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //獲取請求參數(shù)
        String username=req.getParameter("username");
        String password=req.getParameter("password");
        User user=new User(null,username,password,null);
        //判斷用戶的賬號密碼是否正確
        if(userServce.login(user)!=null){
            //登錄成功跳轉(zhuǎn)到登錄成功頁面
            System.out.println("登錄成功");
            req.getRequestDispatcher("/pages/user/login_success.jsp").forward(req,resp);
        }else{
            //賬號或密碼不正確
            System.out.println("賬號或密碼不正確");
            req.getRequestDispatcher("/pages/user/login.jsp").forward(req,resp);
        }
    }
}

以上就是本文的全部內(nèi)容，希望對大家的學(xué)習(xí)有所幫助，也希望大家多多支持腳本之家。

您可能感興趣的文章: