販売管理システムのケーススタディ 第15章: 請求・回収管理

目次

第15章: 請求・回収管理

15.1 請求データの生成

請求ドメインモデルの概要

請求は、売上データを集計して顧客に対する請求書を発行する業務です。締め処理によって売上を集約し、請求データを生成します。

売上からの請求作成

請求は締め日に売上データを集計して生成されます。

請求エンティティの実装

/**
 * 請求
 */
@Value
@RequiredArgsConstructor
@Builder(toBuilder = true)
public class Invoice {
    final InvoiceNumber invoiceNumber; // 請求番号
    final InvoiceDate invoiceDate; // 請求日
    final PartnerCode partnerCode; // 取引先コード
    final CustomerCode customerCode; // 顧客コード
    final Money previousPaymentAmount; // 前回入金額
    final Money currentMonthSalesAmount; // 当月売上額
    final Money currentMonthPaymentAmount; // 当月入金額
    final Money currentMonthInvoiceAmount; // 当月請求額
    final Money consumptionTaxAmount; // 消費税金額
    final Money invoiceReconciliationAmount; // 請求消込金額
    final List<InvoiceLine> invoiceLines; // 請求明細

    public static Invoice of(
            String invoiceNumber,
            LocalDateTime invoiceDate,
            String partnerCode,
            Integer customerBranchNumber,
            Integer previousPaymentAmount,
            Integer currentMonthSalesAmount,
            Integer currentMonthPaymentAmount,
            Integer currentMonthInvoiceAmount,
            Integer consumptionTaxAmount,
            Integer invoiceReconciliationAmount,
            List<InvoiceLine> invoiceLines) {
        return new Invoice(
            new InvoiceNumber(invoiceNumber),
            InvoiceDate.of(invoiceDate),
            PartnerCode.of(partnerCode),
            CustomerCode.of(partnerCode, customerBranchNumber),
            Money.of(previousPaymentAmount),
            Money.of(currentMonthSalesAmount),
            Money.of(currentMonthPaymentAmount),
            Money.of(currentMonthInvoiceAmount),
            Money.of(consumptionTaxAmount),
            Money.of(invoiceReconciliationAmount),
            invoiceLines != null ? invoiceLines : new ArrayList<>()
        );
    }

    /**
     * 請求明細を追加
     */
    public Invoice addInvoiceLine(InvoiceLine invoiceLine) {
        List<InvoiceLine> newInvoiceLines = new ArrayList<>(this.invoiceLines);
        newInvoiceLines.add(invoiceLine);
        return new Invoice(
            this.invoiceNumber,
            this.invoiceDate,
            this.partnerCode,
            this.customerCode,
            this.previousPaymentAmount,
            this.currentMonthSalesAmount,
            this.currentMonthPaymentAmount,
            this.currentMonthInvoiceAmount,
            this.consumptionTaxAmount,
            this.invoiceReconciliationAmount,
            newInvoiceLines
        );
    }
}

請求明細の実装

請求明細は、売上データへの参照を保持します。

/**
 * 請求明細
 */
@Value
@RequiredArgsConstructor
@Builder(toBuilder = true)
public class InvoiceLine {
    final InvoiceNumber invoiceNumber; // 請求番号
    final SalesNumber salesNumber; // 売上番号
    final Integer salesLineNumber; // 売上行番号

    public static InvoiceLine of(
            String invoiceNumber,
            String salesNumber,
            Integer salesLineNumber) {
        return new InvoiceLine(
            InvoiceNumber.of(invoiceNumber),
            SalesNumber.of(salesNumber),
            salesLineNumber
        );
    }
}

請求番号の採番

請求番号は、受注番号と同様に自動採番されます。

/**
 * 請求番号
 */
@Value
@RequiredArgsConstructor
public class InvoiceNumber {
    String value;

    public static InvoiceNumber of(String value) {
        if (value == null || value.isEmpty()) {
            throw new IllegalArgumentException("請求番号は必須です");
        }
        return new InvoiceNumber(value);
    }

    public static String generate(String code, LocalDateTime yearMonth,
                                  Integer autoNumber) {
        isTrue(code.equals(DocumentTypeCode.請求.getCode()),
               "請求番号は先頭が" + DocumentTypeCode.請求.getCode() +
               "で始まる必要があります");
        return code +
               yearMonth.format(DateTimeFormatter.ofPattern("yyMM")) +
               String.format("%04d", autoNumber);
    }
}

締め処理の設計

締め処理は、顧客の請求条件に基づいて実行されます。

---

15.2 入金管理

入金ドメインモデル

入金は、顧客からの支払いを記録し、請求との消込を行います。

入金登録の流れ

請求残高の計算

消込処理の実装

/**
 * 消込処理サービス
 */
@Service
@RequiredArgsConstructor
public class ReconciliationService {
    private final InvoiceRepository invoiceRepository;
    private final PaymentRepository paymentRepository;

    /**
     * 自動消込処理
     * FIFO（先入先出）方式で古い請求から消込
     */
    public List<InvoiceReconciliation> autoReconcile(
            CustomerCode customerCode,
            Money paymentAmount) {

        // 未消込請求を請求日順に取得
        List<Invoice> unpaidInvoices = invoiceRepository
            .findUnpaidByCustomer(customerCode)
            .stream()
            .sorted(Comparator.comparing(
                i -> i.getInvoiceDate().getValue()))
            .collect(Collectors.toList());

        List<InvoiceReconciliation> reconciliations = new ArrayList<>();
        Money remainingAmount = paymentAmount;

        for (Invoice invoice : unpaidInvoices) {
            if (remainingAmount.isZero()) {
                break;
            }

            Money invoiceBalance = invoice.getCurrentMonthInvoiceAmount()
                .subtract(invoice.getInvoiceReconciliationAmount());

            Money reconcileAmount = remainingAmount.isGreaterThan(invoiceBalance)
                ? invoiceBalance
                : remainingAmount;

            reconciliations.add(new InvoiceReconciliation(
                invoice.getInvoiceNumber(),
                reconcileAmount,
                LocalDateTime.now()
            ));

            remainingAmount = remainingAmount.subtract(reconcileAmount);
        }

        return reconciliations;
    }
}

---

請求・入金の状態管理

請求ステータス

入金方法の定義

/**
 * 入金方法
 */
public enum PaymentMethodType {
    銀行振込(1, "銀行口座への振込"),
    現金(2, "現金による支払い"),
    手形(3, "手形による支払い"),
    小切手(4, "小切手による支払い"),
    相殺(5, "債権債務の相殺"),
    その他(9, "その他の方法");

    private final int code;
    private final String description;

    PaymentMethodType(int code, String description) {
        this.code = code;
        this.description = description;
    }

    public static PaymentMethodType fromCode(int code) {
        for (PaymentMethodType type : values()) {
            if (type.code == code) {
                return type;
            }
        }
        throw new IllegalArgumentException("不正な入金方法: " + code);
    }
}

---

TDD によるテスト

請求作成のテスト

@DisplayName("請求")
class InvoiceTest {

    @Test
    @DisplayName("請求を作成できる")
    void shouldCreateInvoice() {
        Invoice invoice = Invoice.of(
            "IV24010001",
            LocalDateTime.of(2024, 1, 31, 0, 0),
            "001",
            1,
            10000,  // 前回入金額
            50000,  // 当月売上額
            0,      // 当月入金額
            60000,  // 当月請求額
            5000,   // 消費税額
            0,      // 請求消込金額
            List.of()
        );

        assertAll(
            () -> assertEquals("IV24010001", invoice.getInvoiceNumber().getValue()),
            () -> assertEquals("001", invoice.getPartnerCode().getValue()),
            () -> assertEquals(10000, invoice.getPreviousPaymentAmount().getAmount()),
            () -> assertEquals(50000, invoice.getCurrentMonthSalesAmount().getAmount()),
            () -> assertEquals(60000, invoice.getCurrentMonthInvoiceAmount().getAmount())
        );
    }

    @Test
    @DisplayName("請求明細を追加できる")
    void shouldAddInvoiceLine() {
        Invoice invoice = Invoice.of(
            "IV24010001",
            LocalDateTime.now(),
            "001", 1,
            0, 10000, 0, 10000, 1000, 0,
            List.of()
        );

        InvoiceLine line = InvoiceLine.of("IV24010001", "SL24010001", 1);
        Invoice updatedInvoice = invoice.addInvoiceLine(line);

        assertEquals(1, updatedInvoice.getInvoiceLines().size());
        assertEquals("SL24010001",
            updatedInvoice.getInvoiceLines().get(0).getSalesNumber().getValue());
    }
}

請求番号のテスト

@Nested
@DisplayName("請求番号")
class InvoiceNumberTest {

    @Test
    @DisplayName("請求番号を生成できる")
    void shouldGenerateInvoiceNumber() {
        LocalDateTime yearMonth = LocalDateTime.of(2024, 1, 1, 0, 0);
        String invoiceNumber = InvoiceNumber.generate("IV", yearMonth, 1);

        assertEquals("IV24010001", invoiceNumber);
    }

    @Test
    @DisplayName("請求番号は必須")
    void shouldThrowExceptionWhenInvoiceNumberIsEmpty() {
        assertThrows(IllegalArgumentException.class,
            () -> InvoiceNumber.of(null));
        assertThrows(IllegalArgumentException.class,
            () -> InvoiceNumber.of(""));
    }
}

消込処理のテスト

@Nested
@DisplayName("消込処理")
class ReconciliationTest {

    @Test
    @DisplayName("請求額と入金額が一致する場合は完全消込")
    void shouldFullyReconcileWhenAmountsMatch() {
        Invoice invoice = createInvoiceWithAmount(10000);
        Money paymentAmount = Money.of(10000);

        // 消込後の残高は0
        Money balance = invoice.getCurrentMonthInvoiceAmount()
            .subtract(paymentAmount);

        assertEquals(0, balance.getAmount());
    }

    @Test
    @DisplayName("入金額が請求額より少ない場合は部分消込")
    void shouldPartiallyReconcileWhenPaymentIsLess() {
        Invoice invoice = createInvoiceWithAmount(10000);
        Money paymentAmount = Money.of(5000);

        Money balance = invoice.getCurrentMonthInvoiceAmount()
            .subtract(paymentAmount);

        assertEquals(5000, balance.getAmount());
    }

    @Test
    @DisplayName("複数請求への自動消込（FIFO方式）")
    void shouldAutoReconcileMultipleInvoices() {
        // 請求1: 10,000円（古い）
        // 請求2: 20,000円（新しい）
        // 入金: 25,000円
        // 期待結果: 請求1は完全消込、請求2は15,000円消込

        List<Invoice> invoices = List.of(
            createInvoiceWithAmountAndDate(10000,
                LocalDateTime.of(2024, 1, 10, 0, 0)),
            createInvoiceWithAmountAndDate(20000,
                LocalDateTime.of(2024, 1, 20, 0, 0))
        );

        Money paymentAmount = Money.of(25000);
        Money remaining = paymentAmount;

        for (Invoice invoice : invoices) {
            Money reconcileAmount = remaining.isGreaterThan(
                invoice.getCurrentMonthInvoiceAmount())
                ? invoice.getCurrentMonthInvoiceAmount()
                : remaining;
            remaining = remaining.subtract(reconcileAmount);
        }

        assertEquals(5000, remaining.getAmount()); // 残り5,000円未消込
    }
}

---

15.3 React コンポーネントの実装

請求・入金画面のコンポーネント構成

請求・回収管理画面は、請求一覧、入金一覧、集計画面で構成されています。

請求一覧画面の実装

請求一覧画面では、請求番号、請求日、顧客コード、当月請求額を表示します。

interface InvoiceCollectionViewProps {
    error: string | null;
    message: string | null;
    searchItems: {
        searchInvoiceCriteria: InvoiceCriteriaType;
        setSearchInvoiceCriteria: React.Dispatch<React.SetStateAction<InvoiceCriteriaType>>;
        handleOpenSearchModal: () => void;
    };
    headerItems: {
        handleOpenModal: (invoice?: InvoiceType) => void;
        handleCheckToggleCollection: () => void;
        handleDeleteCheckedCollection: () => void;
    };
    collectionItems: {
        invoices: InvoiceType[];
        handleOpenModal: (invoice: InvoiceType) => void;
        handleDeleteInvoice: (invoiceNumber: string) => void;
        handleCheckInvoice: (invoice: InvoiceType) => void;
    };
    pageNationItems: PageNationItemsProps;
}

export const InvoiceCollectionView: React.FC<Props> = ({
    error,
    message,
    searchItems,
    headerItems,
    collectionItems,
    pageNationItems
}) => (
    <div className="collection-view-object-container">
        <Message error={error} message={message} />
        <div className="collection-view-container">
            <div className="collection-view-header">
                <h1 className="single-view-title">請求一覧</h1>
            </div>
            <div className="collection-view-content">
                <Search
                    searchCriteria={searchItems.searchInvoiceCriteria}
                    setSearchCriteria={searchItems.setSearchInvoiceCriteria}
                    handleSearchAudit={searchItems.handleOpenSearchModal}
                />
                <div className="button-container">
                    <button onClick={headerItems.handleCheckToggleCollection}>
                        一括選択
                    </button>
                    <button onClick={headerItems.handleDeleteCheckedCollection}>
                        一括削除
                    </button>
                </div>
                <ul className="collection-object-list">
                    {collectionItems.invoices.map((invoice) => (
                        <li key={invoice.invoiceNumber}>
                            <input
                                type="checkbox"
                                checked={invoice.checked || false}
                                onChange={() => collectionItems.handleCheckInvoice(invoice)}
                            />
                            <div>請求番号: {invoice.invoiceNumber}</div>
                            <div>請求日: {invoice.invoiceDate.split("T")[0]}</div>
                            <div>顧客コード: {invoice.customerCode}</div>
                            <div>当月請求額: {invoice.currentMonthInvoiceAmount}</div>
                            <button onClick={() => collectionItems.handleOpenModal(invoice)}>
                                編集
                            </button>
                            <button onClick={() =>
                                collectionItems.handleDeleteInvoice(invoice.invoiceNumber)}>
                                削除
                            </button>
                        </li>
                    ))}
                </ul>
            </div>
        </div>
    </div>
);

消込処理 UI

入金詳細画面では、請求との消込処理を行います。未消込の請求を選択して消込金額を入力します。

入金詳細画面の実装

interface PaymentSingleViewProps {
    error: string | null;
    message: string | null;
    isEditing: boolean;
    newPayment: PaymentType;
    setNewPayment: React.Dispatch<React.SetStateAction<PaymentType>>;
    handleCreateOrUpdatePayment: () => void;
    handleCloseModal: () => void;
    handleCustomerSelect: () => void;
    handleInvoiceSelect: () => void;
}

const PaymentForm: React.FC<PaymentFormProps> = ({
    isEditing,
    newPayment,
    setNewPayment,
    handleCustomerSelect,
    handleInvoiceSelect
}) => (
    <div className="single-view-content-item-form">
        <FormInput
            label="入金番号"
            id="paymentNumber"
            value={newPayment.paymentNumber}
            onChange={(e) => setNewPayment({
                ...newPayment,
                paymentNumber: e.target.value
            })}
            disabled={isEditing}
        />
        <FormInput
            label="入金日"
            id="paymentDate"
            type="date"
            value={convertToDateInputFormat(newPayment.paymentDate)}
            onChange={(e) => setNewPayment({
                ...newPayment,
                paymentDate: e.target.value
            })}
        />
        <FormInput
            label="顧客コード"
            id="customerCode"
            value={newPayment.customerCode}
            onClick={handleCustomerSelect}
        />
        <FormInput
            label="入金金額"
            id="paymentAmount"
            type="number"
            value={newPayment.paymentAmount}
            onChange={(e) => setNewPayment({
                ...newPayment,
                paymentAmount: parseInt(e.target.value)
            })}
        />
        <FormSelect
            label="入金方法"
            id="paymentMethod"
            value={newPayment.paymentMethod}
            options={PaymentMethodEnumType}
            onChange={(e) => setNewPayment({
                ...newPayment,
                paymentMethod: e
            })}
        />
        <FormInput
            label="請求番号"
            id="invoiceNumber"
            value={newPayment.invoiceNumber ?? ""}
            onClick={handleInvoiceSelect}
        />
        <FormInput
            label="消込金額"
            id="reconciliationAmount"
            type="number"
            value={newPayment.reconciliationAmount ?? 0}
            onChange={(e) => setNewPayment({
                ...newPayment,
                reconciliationAmount: parseInt(e.target.value)
            })}
        />
    </div>
);

集計画面の実装

請求集計画面では、顧客別・期間別の請求残高を表示します。

interface InvoiceAggregateCollectionViewProps {
    aggregates: InvoiceAggregateType[];
    criteria: InvoiceAggregateCriteriaType;
    setCriteria: React.Dispatch<React.SetStateAction<InvoiceAggregateCriteriaType>>;
    handleSearch: () => void;
}

export const InvoiceAggregateCollectionView: React.FC<Props> = ({
    aggregates,
    criteria,
    setCriteria,
    handleSearch
}) => (
    <div className="collection-view-object-container">
        <div className="collection-view-header">
            <h1>請求集計</h1>
        </div>
        <div className="collection-view-content">
            <div className="search-container">
                <FormInput
                    label="集計開始日"
                    type="date"
                    value={criteria.startDate}
                    onChange={(e) => setCriteria({
                        ...criteria,
                        startDate: e.target.value
                    })}
                />
                <FormInput
                    label="集計終了日"
                    type="date"
                    value={criteria.endDate}
                    onChange={(e) => setCriteria({
                        ...criteria,
                        endDate: e.target.value
                    })}
                />
                <button onClick={handleSearch}>集計</button>
            </div>
            <table className="aggregate-table">
                <thead>
                    <tr>
                        <th>顧客コード</th>
                        <th>顧客名</th>
                        <th>請求金額</th>
                        <th>入金金額</th>
                        <th>残高</th>
                    </tr>
                </thead>
                <tbody>
                    {aggregates.map((agg) => (
                        <tr key={agg.customerCode}>
                            <td>{agg.customerCode}</td>
                            <td>{agg.customerName}</td>
                            <td>{agg.invoiceAmount.toLocaleString()}</td>
                            <td>{agg.paymentAmount.toLocaleString()}</td>
                            <td>{agg.balance.toLocaleString()}</td>
                        </tr>
                    ))}
                </tbody>
            </table>
        </div>
    </div>
);

型定義

// 請求の型定義
export interface InvoiceType {
    invoiceNumber: string;
    invoiceDate: string;
    partnerCode: string;
    customerCode: string;
    customerBranchNumber: number;
    previousPaymentAmount: number;
    currentMonthSalesAmount: number;
    currentMonthPaymentAmount: number;
    currentMonthInvoiceAmount: number;
    consumptionTaxAmount: number;
    invoiceReconciliationAmount: number;
    invoiceLines: InvoiceLineType[];
    checked?: boolean;
}

// 請求明細の型定義
export interface InvoiceLineType {
    invoiceNumber: string;
    salesNumber: string;
    salesLineNumber: number;
}

// 入金の型定義
export interface PaymentType {
    paymentNumber: string;
    paymentDate: string;
    customerCode: string;
    customerBranchNumber: number;
    paymentAmount: number;
    paymentMethod: PaymentMethodEnumType;
    invoiceNumber?: string;
    reconciliationAmount?: number;
    checked?: boolean;
}

// 入金方法の列挙型
export enum PaymentMethodEnumType {
    銀行振込 = "銀行振込",
    現金 = "現金",
    手形 = "手形",
    小切手 = "小切手",
    相殺 = "相殺",
    その他 = "その他"
}

// 請求集計の型定義
export interface InvoiceAggregateType {
    customerCode: string;
    customerName: string;
    invoiceAmount: number;
    paymentAmount: number;
    balance: number;
}

---

まとめ

本章では、請求・回収管理の実装について解説しました。

• 請求データの生成: 売上からの請求作成、締め処理、請求番号の採番
• 入金管理: 入金登録、FIFO方式による自動消込、残高管理
• React コンポーネント: 請求・入金画面、消込処理 UI、集計画面

第4部「販売管理機能」では、受注から請求・回収までの一連の販売プロセスを実装しました。次の第5部では、調達管理機能として発注・仕入・支払の実装に進みます。