# Business Logic — FUW00114SF03DBean.listKoumokuIds() [6 LOC]

| Field | Value |
|-------|-------|
| Fully Qualified Name | `eo.web.webview.FUW00114SF.FUW00114SF03DBean` |
| Layer | Webview (View/Data Bean — Presentation layer) |
| Module | `FUW00114SF` (Package: `eo.web.webview.FUW00114SF`) |

## 1. Role

### FUW00114SF03DBean.listKoumokuIds()

This method is a data-type bean utility that returns a predefined list of item label strings (field display names) used by the `FUW00114SF03DBean` data type view component within the EO Light network service ordering system. It implements a **static factory pattern** — providing a self-contained data source for UI rendering without requiring bean instantiation. The returned list contains exactly two Japanese strings that correspond to column headers for the "Customer-facing mail detail list" (`お客様向けメール明細一覧リスト`) screen, representing the mail detail code field and the detail body non-standard replacement character field. This method serves as a **lookup data provider** for data-type view screens, where the framework uses these labels to dynamically render form fields, dropdown options, or data grid columns. It is invoked indirectly through the parent `FUW00114SFBean.listKoumokuIds(String key)` routing dispatcher, which selects the appropriate DBean subclass based on the requested item key.

## 2. Processing Pattern (Detailed Business Logic)

```mermaid
flowchart TD
    START(["listKoumokuIds()"])
    CRE["Create ArrayList<String> koumokuList"]
    ADD1["Add: メール明細コード (Mail Detail Code)"]
    ADD2["Add: 明細本文非定型置換文字 (Detail Body Non-standard Replacement Characters)"]
    RET["Return koumokuList"]

    START --> CRE
    CRE --> ADD1
    ADD1 --> ADD2
    ADD2 --> RET
```

This method performs **straight-line sequential processing** with no conditional branches. It creates a new `ArrayList`, adds two hardcoded Japanese label strings representing column field names for the mail detail list screen, and returns the list. There are no loops, no conditionals, and no external calls.

## 3. Parameter Analysis

| No | Parameter Name | Type | Business Description |
|----|---------------|------|---------------------|
| - | (none) | - | This is a static method with no parameters. It returns a complete, self-contained list of field labels for the data type view. |

## 4. CRUD Operations / Called Services

This method performs **no CRUD operations**. It is a pure data-returning utility that constructs and returns a static list of strings without any interaction with services, databases, or external state.

| CRUD | SC / CBS | SC Code | Entity / DB | Operation Description |
|------|----------|---------|-------------|----------------------|
| — | — | — | — | No service calls or data operations. Pure data factory. |

## 5. Dependency Trace

| # | Caller (Screen/Batch) | Call Chain (Full Path to this Method) | Terminal (SC / CRUD / Entity) |
|---|----------------------|--------------------------------------|-------------------------------|
| 1 | Screen: FUW00114SFBean | `FUW00114SFBean.listKoumokuIds("お客様向けメール明細一覧リスト")` -> `FUW00114SF03DBean.listKoumokuIds()` | — (no CRUD, pure data) |

**Caller Details:**

| # | Caller | Type | Call Chain |
|---|--------|------|------------|
| 1 | `FUW00114SFBean` (List of 9 DBean subclasses) | Dispatcher/Router | The parent bean method `listKoumokuIds(String key)` routes to this method when the `key` parameter equals `"お客様向けメール明細一覧リスト"` (Customer-facing mail detail list). |

The parent `FUW00114SFBean.listKoumokuIds(String key)` is the primary caller and acts as a **dispatcher/router**, forwarding requests to the appropriate `FUW00114SFxxDBean.listKoumokuIds()` method based on the string key. The key `"お客様向けメール明細一覧リスト"` triggers the call to `FUW00114SF03DBean.listKoumokuIds()`.

## 6. Per-Branch Detail Blocks

**Block 1** — [LINEAR] `(straight-line, no branches)` (L227)

> Create a new ArrayList and populate it with two hardcoded Japanese field labels for the customer-facing mail detail list screen.

| # | Type | Code |
|---|------|------|
| 1 | SET | `koumokuList = new ArrayList<String>()` // Initialize empty list for field labels |
| 2 | ADD | `koumokuList.add("メール明細コード")` // Add "Mail Detail Code" label |
| 3 | ADD | `koumokuList.add("明細本文非定型置換文字")` // Add "Detail Body Non-standard Replacement Characters" label |

**Block 2** — [RETURN] `(return the populated list)` (L230)

| # | Type | Code |
|---|------|------|
| 1 | RETURN | `return koumokuList` // Return the 2-element list of field labels |

## 7. Glossary

| Term | Type | Business Meaning |
|------|------|------------------|
| `koumokuList` | Field | Item/field list — the ArrayList of Japanese display labels returned by this method |
| `koumoku` | Japanese term | Items / fields / column names — refers to display labels for UI fields in the view layer |
| メール明細コード | Field Label | Mail Detail Code — the identifier for a customer-facing mail detail record |
| 明細本文非定型置換文字 | Field Label | Detail Body Non-standard Replacement Characters — custom placeholder text used in the body of customer-facing mail details |
| FUW00114SF | Module | EO Light network service ordering screen module (Web frontend) |
| DBean | Pattern | Data Bean — a view-layer bean that provides structured data for display screens |
| データタイプビュー | Japanese term | Data Type View — a UI rendering pattern where fields and their properties are defined by data-type beans |
| EO Light | Business term | NTT East's fiber-optic home internet service brand |
| お客様向け | Japanese term | Customer-facing — information displayed to end customers (not internal staff) |
| メール明細一覧 | Japanese term | Mail Detail List — a list of mail/detail records shown to customers |