JavaWeb实现用户登录与注册功能(服务器)
本文实例为大家分享了JavaWeb实现用户登录与注册功能的具体代码,供大家参考,具体内容如下
用到的知识
客户端:HTML CSS JS (JQuery)
服务器:JAVA基础 JSP Servlet JDBC Tomcat
数据库:MySQL
用到的Jar包 druid数据库连接池 dbutils JDBC数据库操作工具 MySQL jar包
总体结构:
客户端数据库部分网址
思路:
服务器部分采用JavaEE三层架构
(1)、表现层:通俗讲就是展现给用户的界面,即用户在使用一个系统的时候他的所见所得。
(2)、业务逻辑层:针对具体问题的操作,也可以说是对数据层的操作,对数据业务逻辑处理。
(3)、数据访问层:该层所做事务直接操作数据库,针对数据的增添、删除、修改、查找等。
先创建基本的文件夹架构,三层的文件夹依次为web ,servlet ,DAO。 此外还有其他相关文件夹工具类utils,JAVABean类pojo,测试类test 。依次实现从DAO层到Servce层再到Web层。
文件夹架构
资源文件 jdbc.properties
username=root password=123456 url=jdbc:mysql://localhost:3306/book driverClassName=com.mysql.jdbc.Driver initialSize=5 maxActive=10
一、DAO层
0.写好JAVABean User类
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.先实现数据连接
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; //数据库连接池初始化 static { try { InputStream resourceAsStream = JDBCUtils.class.getClassLoader().getResourceAsStream("jdbc.properties");//类加载器默认是从classPath路径加载资源 Properties properties = new Properties(); properties.load(resourceAsStream); //创建数据库连接池 druidDataSource = (DruidDataSource) DruidDataSourceFactory.createDataSource(properties); } catch (Exception e) { System.out.println("数据库连接池初始化异常"); } } //获取数据库连接池中的连接 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.测试连接是否成功
3.编写BaseDAO 实现对数据库的基本通用操作
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(); //数据库通用操作,使用dbutils来操作 //用来执行updata,delete,insert public int updata(String sql,Object...objects){ Connection connection= JDBCUtils.getConnection(); try { return queryRunner.update(connection,sql,objects);//返回影响的行数 } catch (SQLException throwables) { throwables.printStackTrace(); } return -1; } //用来执行查询操作 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; } //查询多个结果 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; } //查询单个数 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.编写UserDAO接口确定需要的操作
package com.book.DAO; import com.book.pojo.User; public interface UserDAO { // 注册时判断是否该用户名已经被注册 根据用户名查询用户信息 如果返回null说明没有该用户 public User queryUserByUsername(String username); //注册成功 保存用户信息 public int saveUser(User user); //登录操作 根据用户名和密码查询用户 查不到返回null public User queryUserByUsernameAndPassword(String username,String password); }
5.UserDAOImpl实现UserDAO接口
package com.book.DAO; import com.book.pojo.User; //所犯错误:继承的子类会有父类的全部方法,不要在子类中声明父类对象,调用父类方法 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; } //所犯错误:输入的邮箱不能重复 @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层
1.UserServce接口确定业务需要的方法,用来与Web层进行交互
package com.book.servlet; import com.book.pojo.User; //业务层一个业务一个方法 public interface UserServce { //注册业务 注册成功将用户保存到数据库中 public void registUser(User user); //登录业务 public User login(User user); //检查用户名是否可用 返回true表示用户名已存在 public boolean existUsername(String username); }
2.UserServceImpl类实现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) { //用户名不存在 if(userDAO.queryUserByUsername(username)==null){ return false; }else { return true; } } }
三、Web层
1.注册操作
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(); //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"); //判断验证码是否正确 忽略大小写 if("6n6np".equalsIgnoreCase(code)){ //判断是否存在用户名 if(!userServce.existUsername(username)){ //不存在则将注册信息写入数据库 User user=new User(null,username,password,email); userServce.registUser(user); //请求转发到注册成功页面 req.getRequestDispatcher("/pages/user/regist_success.jsp").forward(req,resp); }else{ System.out.println("用户名已存在"); //跳转到注册页面 req.getRequestDispatcher("/pages/user/regist.jsp").forward(req,resp); } }else { System.out.println("验证码错误"); //跳转到注册页面 req.getRequestDispatcher("/pages/user/login.jsp").forward(req,resp); } } }
2.登录操作
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 { //获取请求参数 String username=req.getParameter("username"); String password=req.getParameter("password"); User user=new User(null,username,password,null); //判断用户的账号密码是否正确 if(userServce.login(user)!=null){ //登录成功跳转到登录成功页面 System.out.println("登录成功"); req.getRequestDispatcher("/pages/user/login_success.jsp").forward(req,resp); }else{ //账号或密码不正确 System.out.println("账号或密码不正确"); req.getRequestDispatcher("/pages/user/login.jsp").forward(req,resp); } } }
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持我们。
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