# Business Logic — KKW22301SF01DBean.listKoumokuIds() [7 LOC]

| Field | Value |
|-------|-------|
| Fully Qualified Name | `eo.web.webview.KKW22301SF.KKW22301SF01DBean` |
| Layer | Data Bean / UI Component (webview tier) |
| Module | `KKW22301SF` (Package: `eo.web.webview.KKW22301SF`) |

## 1. Role

### KKW22301SF01DBean.listKoumokuIds()

This method serves as a **metadata factory** for the KKW22301SF screen's data-type view, providing the canonical list of item (field) names that the UI should render. It is a static utility method that returns a fixed ArrayList of three Japanese-labeled column identifiers — "Service Contract Number" (サービス契約番号), "SISID" (a system-level internal identifier), and "Billing Contract Number" (請求契約番号). As a shared data bean method, it follows a **registry/dispatch pattern**: instead of hard-coding field names at each call site, the screen controller queries this single source of truth to determine what columns to display in a data grid or detail view. Its role in the larger system is to ensure consistency across the KKW22301SF screen by centralizing the definition of visible data items, so that any UI change or field reordering flows from one method rather than being scattered across JSP/HTML templates and controller logic.

## 2. Processing Pattern (Detailed Business Logic)

```mermaid
flowchart TD
    START(["listKoumokuIds()"])
    STEP1["Create ArrayList"]
    STEP2["Add ServiceContractNo"]
    STEP3["Add SISID"]
    STEP4["Add BillingContractNo"]
    END_RETURN(["Return list"])

    START --> STEP1
    STEP1 --> STEP2
    STEP2 --> STEP3
    STEP3 --> STEP4
    STEP4 --> END_RETURN
```

This is a sequential, linear processing flow with no conditional branches. The method:

1. Instantiates an empty `ArrayList<String>` to hold item name strings.
2. Appends three hardcoded Japanese labels in a fixed order (service contract number, SISID, billing contract number).
3. Returns the populated list.

**No constant resolution required** — the method uses literal string values directly. No external service calls, database reads, or configuration lookups are involved.

## 3. Parameter Analysis

| No | Parameter Name | Type | Business Description |
|----|---------------|------|---------------------|
| - | (none) | - | This is a static method with no parameters. It does not accept any input. |
| - | (instance state) | - | This method does not read any instance fields or external state. It is purely self-contained. |

The method has no parameters and no dependency on runtime state. It always returns the same fixed list of three item names regardless of context, making it a pure constant-producing utility.

## 4. CRUD Operations / Called Services

This method performs no CRUD operations. It does not invoke any Service Component (SC), Callback Service (CBS), database queries, or external services. It is a pure data producer that constructs an in-memory ArrayList and returns it.

| CRUD | SC / CBS | SC Code | Entity / DB | Operation Description |
|------|----------|---------|-------------|----------------------|
| N/A | N/A | N/A | N/A | No database or service operations. Pure in-memory list construction. |

## 5. Dependency Trace

No callers were found in the codebase for `listKoumokuIds()`. This method is defined as `public static`, indicating it is designed to be called by other components, but no current callers reference it. It may be used by:
- The KKW22301SF screen controller or JSP view for column header generation.
- The companion `KKW22301SF02DBean` or `KKW22301SF03DBean` data beans.
- External consumers not yet included in the scanned codebase.

| # | Caller (Screen/Batch) | Call Chain (Full Path to this Method) | Terminal (SC / CRUD / Entity) |
|---|----------------------|--------------------------------------|-------------------------------|
| 1 | No callers found | N/A | N/A |

## 6. Per-Branch Detail Blocks

The method has no conditional branches (no if/else, switch, loops, or try/catch). It is a single sequential block.

**Block 1** — [SEQUENTIAL] `(none)` (L318)

> Creates and populates a list of three display field names for the data-type view. No branching, no external calls.

| # | Type | Code |
|---|------|------|
| 1 | SET | `ArrayList<String> koumokuList = new ArrayList<String>();` — Initialize an empty ArrayList for item names [L320] |
| 2 | SET | `koumokuList.add("サービス契約番号")` — Add "Service Contract Number" (内部でのサービス契約の一意識別番号) [L321] |
| 3 | SET | `koumokuList.add("SISID")` — Add "SISID" (システムID — system internal identifier) [L322] |
| 4 | SET | `koumokuList.add("請求契約番号")` — Add "Billing Contract Number" (課金に関する契約の一意識別番号) [L323] |
| 5 | RETURN | `return koumokuList;` — Return the list containing 3 item names [L324] |

## 7. Glossary

| Term | Type | Business Meaning |
|------|------|------------------|
| `サービス契約番号` | Field | Service Contract Number — unique identifier for a customer's service contract line item |
| `SISID` | Field | System ID — internal system-level identifier used for cross-referencing service records |
| `請求契約番号` | Field | Billing Contract Number — unique identifier for a billing-related contract, used in invoicing and payment processing |
| DBean | Acronym | Data Bean — a UI-tier data structure class in the webview layer that holds and transfers display data between the controller and the view (JSP) |
| KKW22301SF | Module | Screen module identifier for the service contract data-type view screen (web-based) |
| ArrayList | Technical | Java dynamic array collection — used here as the return type for an ordered list of field names |
| Koumoku | Japanese (項目) | Item/Field — refers to display columns or data fields shown in a UI grid or form |