サーブレット&JSPの基本｜みんなのショッピングのログイン機能を作成しよう

package model;

public class CustomerLogin {
    private String customerId;
    private String loginPass;

    public CustomerLogin(String customerId, String loginPass) {
        this.customerId = customerId;
        this.loginPass = loginPass;
    }

    public String getCustomerId() {
        return customerId;
    }

    public String getLoginPass() {
        return loginPass;
    }
}

package model;

public class CustomerAccount {
    private String customerId;
    private String loginPass;
    private String email;
    private String customerName;
    private int age;

    public CustomerAccount(String customerId, String loginPass,
            String email, String customerName, int age) {
        this.customerId = customerId;
        this.loginPass = loginPass;
        this.email = email;
        this.customerName = customerName;
        this.age = age;
    }

    public String getCustomerId() {
        return customerId;
    }

    public String getLoginPass() {
        return loginPass;
    }

    public String getEmail() {
        return email;
    }

    public String getCustomerName() {
        return customerName;
    }

    public int getAge() {
        return age;
    }
}

package dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import model.CustomerAccount;
import model.CustomerLogin;

public class CustomersDAO {
    private final String JDBC_URL =
            "jdbc:h2:tcp://localhost/~/minnaMarket";
    private final String DB_USER = "sa";
    private final String DB_PASS = "";

    public CustomerAccount findByLogin(CustomerLogin login) {
        CustomerAccount account = null;

        // JDBCドライバを読み込む
        try {
            Class.forName("org.h2.Driver");
        } catch (ClassNotFoundException e) {
            throw new IllegalStateException(
                    "JDBCドライバを読み込めませんでした");
        }

        // データベースへ接続
        try (Connection conn = DriverManager.getConnection(
                JDBC_URL, DB_USER, DB_PASS)) {

            // SELECT文を準備
            String sql = "SELECT CUSTOMER_ID, LOGIN_PASS, EMAIL, "
                    + "CUSTOMER_NAME, AGE "
                    + "FROM CUSTOMERS "
                    + "WHERE CUSTOMER_ID = ? AND LOGIN_PASS = ?";
            PreparedStatement pStmt = conn.prepareStatement(sql);
            pStmt.setString(1, login.getCustomerId());
            pStmt.setString(2, login.getLoginPass());

            // SELECT文を実行し、結果表を取得
            ResultSet rs = pStmt.executeQuery();

            if (rs.next()) {
                // 会員が存在したらデータを取得し、
                // CustomerAccountインスタンスを作成する
                String customerId = rs.getString("CUSTOMER_ID");
                String loginPass = rs.getString("LOGIN_PASS");
                String email = rs.getString("EMAIL");
                String customerName = rs.getString("CUSTOMER_NAME");
                int age = rs.getInt("AGE");

                account = new CustomerAccount(customerId, loginPass,
                        email, customerName, age);
            }
        } catch (SQLException e) {
            e.printStackTrace();
            return null;
        }

        return account;
    }
}

package test;

import dao.CustomersDAO;
import model.CustomerAccount;
import model.CustomerLogin;

public class CustomersDAOCheck {
    public static void main(String[] args) {
        testFindByLoginOK();
        testFindByLoginNG();
    }

    public static void testFindByLoginOK() {
        CustomerLogin login = new CustomerLogin("miyu", "1234");
        CustomersDAO dao = new CustomersDAO();
        CustomerAccount result = dao.findByLogin(login);

        if (result != null
                && result.getCustomerId().equals("miyu")
                && result.getLoginPass().equals("1234")
                && result.getEmail().equals("miyu.tanaka@example.jp")
                && result.getCustomerName().equals("田中 美優")
                && result.getAge() == 28) {
            System.out.println("testFindByLoginOK:成功しました");
        } else {
            System.out.println("testFindByLoginOK:失敗しました");
        }
    }

    public static void testFindByLoginNG() {
        CustomerLogin login = new CustomerLogin("miyu", "9999");
        CustomersDAO dao = new CustomersDAO();
        CustomerAccount result = dao.findByLogin(login);

        if (result == null) {
            System.out.println("testFindByLoginNG:成功しました");
        } else {
            System.out.println("testFindByLoginNG:失敗しました");
        }
    }
}

testFindByLoginOK:成功しました
testFindByLoginNG:成功しました

package model;

import dao.CustomersDAO;

public class CustomerLoginLogic {
    public boolean execute(CustomerLogin login) {
        CustomersDAO dao = new CustomersDAO();
        CustomerAccount account = dao.findByLogin(login);
        return account != null;
    }
}

package test;

import model.CustomerLogin;
import model.CustomerLoginLogic;

public class CustomerLoginLogicCheck {
    public static void main(String[] args) {
        testExecuteOK();
        testExecuteNG();
    }

    public static void testExecuteOK() {
        CustomerLogin login = new CustomerLogin("miyu", "1234");
        CustomerLoginLogic bo = new CustomerLoginLogic();
        boolean result = bo.execute(login);

        if (result) {
            System.out.println("testExecuteOK:成功しました");
        } else {
            System.out.println("testExecuteOK:失敗しました");
        }
    }

    public static void testExecuteNG() {
        CustomerLogin login = new CustomerLogin("miyu", "9999");
        CustomerLoginLogic bo = new CustomerLoginLogic();
        boolean result = bo.execute(login);

        if (!result) {
            System.out.println("testExecuteNG:成功しました");
        } else {
            System.out.println("testExecuteNG:失敗しました");
        }
    }
}

testExecuteOK:成功しました
testExecuteNG:成功しました

package servlet;

import java.io.IOException;

import jakarta.servlet.RequestDispatcher;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

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

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

        RequestDispatcher dispatcher = request.getRequestDispatcher(
                "WEB-INF/jsp/marketTop.jsp");
        dispatcher.forward(request, response);
    }
}

<%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8" %>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>みんなのショッピング</title>
</head>
<body>
<h1>みんなのショッピング</h1>
<ul>
<li><a href="CustomerLoginServlet">ログイン</a></li>
<li>ユーザー登録</li>
</ul>
</body>
</html>

package servlet;

import java.io.IOException;

import jakarta.servlet.RequestDispatcher;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

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

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

        RequestDispatcher dispatcher = request.getRequestDispatcher(
                "WEB-INF/jsp/customerLogin.jsp");
        dispatcher.forward(request, response);
    }

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

        RequestDispatcher dispatcher = request.getRequestDispatcher(
                "WEB-INF/jsp/customerLoginOK.jsp");
        dispatcher.forward(request, response);
    }
}

<%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8" %>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>みんなのショッピング</title>
</head>
<body>
<h1>ログイン</h1>
<form action="CustomerLoginServlet" method="post">
ユーザーID：<input type="text" name="customerId"><br>
パスワード：<input type="password" name="loginPass"><br>
<input type="submit" value="ログイン">
</form>
</body>
</html>

<%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8" %>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>みんなのショッピング</title>
</head>
<body>
<h1>ログイン成功</h1>
<p>ようこそ［ユーザーID］さん</p>
<a href="MarketTopServlet">トップへ</a>
</body>
</html>

package servlet;

import java.io.IOException;

import jakarta.servlet.RequestDispatcher;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import jakarta.servlet.http.HttpSession;

import model.CustomerLogin;
import model.CustomerLoginLogic;

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

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

        RequestDispatcher dispatcher = request.getRequestDispatcher(
                "WEB-INF/jsp/customerLogin.jsp");
        dispatcher.forward(request, response);
    }

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

        // リクエストパラメータの取得
        request.setCharacterEncoding("UTF-8");
        String customerId = request.getParameter("customerId");
        String loginPass = request.getParameter("loginPass");

        // ログイン処理の実行
        CustomerLogin login = new CustomerLogin(customerId, loginPass);
        CustomerLoginLogic bo = new CustomerLoginLogic();
        boolean result = bo.execute(login);

        // ログイン処理の成否によって処理を分岐
        if (result) {
            // セッションスコープにユーザーIDを保存
            HttpSession session = request.getSession();
            session.setAttribute("customerId", customerId);

            // ログイン成功画面へフォワード
            RequestDispatcher dispatcher = request.getRequestDispatcher(
                    "WEB-INF/jsp/customerLoginOK.jsp");
            dispatcher.forward(request, response);
        } else {
            // ログイン画面へリダイレクト
            response.sendRedirect("CustomerLoginServlet");
            return;
        }
    }
}

<%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8" %>
<%@ taglib prefix="c" uri="jakarta.tags.core" %>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>みんなのショッピング</title>
</head>
<body>
<h1>ログイン成功</h1>
<p>ようこそ<c:out value="${customerId}" />さん</p>
<a href="MarketTopServlet">トップへ</a>
</body>
</html>