java之页面连接eclipse连接数据库实现注册,登录功能

实体类Users

package com.qf.entity;

public class Users {
	private int id;//ID
	private String username;//账号
	private String pwd;//密码
	private int age;//年龄
	private String sex;//性别
	public Users() {
		super();
		// TODO Auto-generated constructor stub
	}
	public Users(int id, String username, String pwd, int age, String sex) {
		super();
		this.id = id;
		this.username = username;
		this.pwd = pwd;
		this.age = age;
		this.sex = sex;
	}
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getPwd() {
		return pwd;
	}
	public void setPwd(String pwd) {
		this.pwd = pwd;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	public String getSex() {
		return sex;
	}
	public void setSex(String sex) {
		this.sex = sex;
	}
	@Override
	public String toString() {
		return "Users [id=" + id + ", username=" + username + ", pwd=" + pwd + ", age=" + age + ", sex=" + sex + "]";
	}
}

工具类DBManager

package com.qf.util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class DBManager {
	public static Connection getConnection() throws ClassNotFoundException, SQLException {
		// 1.加载驱动
		Class.forName("com.mysql.jdbc.Driver");
		// 2. 获得连接, 三个参数分别为：url，用户名，密码
		return DriverManager
				.getConnection("jdbc:mysql://localhost:3306/j1904?useUnicode=true&characterEncoding=utf-8", 
				"root", "root");
	}
	
	// 先打开，后关闭
	public static void closeAll(Connection connection, PreparedStatement statement) {
		try {
			if(statement != null) {
				statement.close();
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}finally {
			try {
				if(connection != null) {
					connection.close();
				}
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}
	
	// 先打开，后关闭
	public static void closeAll(Connection connection, PreparedStatement statement, ResultSet resultSet) {
		try {
			if(resultSet != null) {
				resultSet.close();
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}finally {
			closeAll(connection, statement);
		}
	}
}

数据库操作类UsersDAO

package com.qf.dao;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

import com.qf.entity.Users;
import com.qf.util.DBManager;

public class UsersDAO {
	public static boolean insert(Users user) {
		Connection connection = null;
		PreparedStatement statement = null;
		try {
			connection = DBManager.getConnection();
			String sql = "INSERT INTO users(username, pwd, age, sex) VALUES (?, ?, ?, ?);";
			statement = connection.prepareStatement(sql);
			statement.setString(1, user.getUsername());
			statement.setString(2, user.getPwd());
			statement.setInt(3, user.getAge());
			statement.setString(4, user.getSex());
			int count = statement.executeUpdate();
			return count > 0;
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			DBManager.closeAll(connection, statement);
		}
		return false;
	}
	
	public static boolean update(Users user) {
		Connection connection = null;
		PreparedStatement statement = null;
		try {
			connection = DBManager.getConnection();
			String sql = "UPDATE users SET username = ?, pwd = ?, age = ?, sex = ? WHERE id = ?;";
			statement = connection.prepareStatement(sql);
			statement.setString(1, user.getUsername());
			statement.setString(2, user.getPwd());
			statement.setInt(3, user.getAge());
			statement.setString(4, user.getSex());
			statement.setInt(5, user.getId());
			int count = statement.executeUpdate();
			return count > 0;
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			DBManager.closeAll(connection, statement);
		}
		return false;
	}
	
	public static boolean delete(int id) {
		Connection connection = null;
		PreparedStatement statement = null;
		try {
			connection = DBManager.getConnection();
			String sql = "DELETE FROM users WHERE id = ?;";
			statement = connection.prepareStatement(sql);
			statement.setInt(1, id);
			int count = statement.executeUpdate();
			return count > 0;
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			DBManager.closeAll(connection, statement);
		}
		return false;
	}
	
	public static Users findById(int id) {
		Connection connection = null;
		PreparedStatement statement = null;
		ResultSet resultSet = null;
		try {
			connection = DBManager.getConnection();
			String sql = "SELECT * FROM users WHERE id = ?;";
			statement = connection.prepareStatement(sql);
			statement.setInt(1, id);
			resultSet = statement.executeQuery();
			while(resultSet.next()) {
				return new Users(resultSet.getInt("id"), 
						resultSet.getString("username"), resultSet.getString("pwd"), resultSet.getInt("age"), resultSet.getString("sex"));
			}
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			DBManager.closeAll(connection, statement, resultSet);
		}
		return null;
	}
	
	public static List<Users> findAll() {
		Connection connection = null;
		PreparedStatement statement = null;
		ResultSet resultSet = null;
		List<Users> list = new ArrayList<>();
		try {
			connection = DBManager.getConnection();
			String sql = "SELECT * FROM users";
			statement = connection.prepareStatement(sql);
			resultSet = statement.executeQuery();
			while(resultSet.next()) {
				Users user = new Users(resultSet.getInt("id"), 
						resultSet.getString("username"), resultSet.getString("pwd"), 
						resultSet.getInt("age"), resultSet.getString("sex"));
				list.add(user);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			DBManager.closeAll(connection, statement, resultSet);
		}
		return list;
	}
}

注册servlet RegServlet

package com.qf.servlet;

import java.io.IOException;
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 com.qf.dao.UsersDAO;
import com.qf.entity.Users;

@WebServlet("/reg")
public class RegServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		request.setCharacterEncoding("utf-8");
		String username = request.getParameter("username");
		String pwd = request.getParameter("pwd");
		String age = request.getParameter("age");
		String sex = request.getParameter("sex");
		int nage = Integer.parseInt(age);
		Users user = new Users(0,username, pwd, nage, sex);
		if(UsersDAO.insert(user)){
			response.sendRedirect("success.html");
		}else {
			response.sendRedirect("fail.html");
		}
	}
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}
}

登录servlet LoginServlet

package com.qf.servlet;

import java.io.IOException;
import java.util.List;

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 com.qf.dao.UsersDAO;
import com.qf.entity.Users;

@WebServlet("/login")
public class LoginServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		request.setCharacterEncoding("utf-8");
		String username = request.getParameter("username");
		String pwd = request.getParameter("pwd");
		List<Users> list = UsersDAO.findAll();
		boolean flag = false;
		for (Users users : list) {
			if (users.getUsername().equals(username) && users.getPwd().equals(pwd)) {
				flag = true;
			}
		}
		if (flag) {
			response.sendRedirect("success.html");
		} else {
			response.sendRedirect("fail.html");
		}
	}

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

注册页面 reg.html

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
	<form action="reg" method="post">
		<input type="text" name="username" placeholder="用户名"/><br/>
		<input type="password" name="pwd" placeholder="密码"/><br/>
		<input type="text" name="age" placeholder="年龄"/><br/>
		<input type="text" name="sex" placeholder="性别"/><br/>
		<input type="submit" value="注册"/>
	</form>
</body>
</html>

登录页面 login.html

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
	<form action="login" method="post">
		<input type="text" name="username" placeholder="用户名"/><br/>
		<input type="password" name="pwd" placeholder="密码"/><br/>
		<input type="submit" value="登录"/>
	</form>
</body>
</html>

成功页面 success.html

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
	<h1>恭喜您成功了</h1>
</body>
</html>

失败页面 fail.html

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
	<h1>操作失败</h1>
</body>
</html>