---

# Business Logic — FUW02401SFLogic.back() [15 LOC]

| Field | Value |
|-------|-------|
| Fully Qualified Name | `eo.web.webview.FUW02401SF.FUW02401SFLogic` |
| Layer | Service (Web Business Logic — extends JCCWebBusinessLogic) |
| Module | `FUW02401SF` (Package: `eo.web.webview.FUW02401SF`) |

## 1. Role

### FUW02401SFLogic.back()

This method handles the **back button** press on the **Homepage URL Name Acquisition Application Confirmation Screen** (ホームページURL名取得申込確認画面). In the broader FUW02401SF screen workflow, users navigate through a multi-step form to request a homepage URL name; at the confirmation step, they may choose to go back to the previous screen rather than submit. The `back()` method prepares the shared navigation context so the framework can redirect the user back to the FUW02401 main screen. It implements a **delegation pattern**, delegating to `getCommonInfoBean()` to access the shared form bean and using `sendMessageString()` to set navigation metadata. This method plays the role of a **screen entry point** — it is the business logic handler invoked when the user activates the back button on the confirmation screen. It performs no conditional branching, no CRUD operations, and no business rule validation; it simply configures navigation state and returns success.

## 2. Processing Pattern (Detailed Business Logic)

```mermaid
flowchart TD
    START(["back()"])
    START --> GET["getCommonInfoBean()"]
    GET --> SEND1["sendMessageString(NEXT_SCREEN_NAME, DATABEAN_SET_VALUE, SCREEN_NAME_FUW02401)"]
    SEND1 --> SEND2["sendMessageString(NEXT_SCREEN_ID, DATABEAN_SET_VALUE, SCREEN_ID_FUW02401)"]
    SEND2 --> RET["return true"]
    RET --> END(["Return true"])
```

**Processing flow:**

1. **Retrieve shared form bean** — Calls `super.getCommonInfoBean()` to obtain an `X31SDataBeanAccess` instance (`commoninfoBean`) that holds shared navigation data across screens.
2. **Set next screen name** — Calls `commoninfoBean.sendMessageString()` with `NEXT_SCREEN_NAME = "遷移先画面名" (Next screen name)` as the key, `DATABEAN_SET_VALUE` as the set mode, and `SCREEN_NAME_FUW02401 = "ホームページURL名取得申込" (Homepage URL Name Acquisition Application)` as the value.
3. **Set next screen ID** — Calls `commoninfoBean.sendMessageString()` with `NEXT_SCREEN_ID = "遷移先画面ID" (Next screen ID)` as the key, `DATABEAN_SET_VALUE` as the set mode, and `SCREEN_ID_FUW02401 = "FUW02401"` as the value.
4. **Return success** — Returns `true` to indicate normal completion.

## 3. Parameter Analysis

| No | Parameter Name | Type | Business Description |
|----|---------------|------|---------------------|
| - | (none) | - | - |

The `back()` method takes **no parameters**. It operates entirely on shared instance state (the common info bean obtained from the parent class `JCCWebBusinessLogic`). The method does not accept input from the user or the calling controller — the navigation target is hardcoded to `FUW02401`.

**Instance fields / external state used:**
| Source | Field / Method | Business Description |
|--------|---------------|---------------------|
| `JCCWebBusinessLogic` (super) | `getCommonInfoBean()` | Retrieves the shared form data bean (`X31SDataBeanAccess`) that carries navigation context across the web session. |

## 4. CRUD Operations / Called Services

### Pre-computed evidence from code analysis graph:

| CRUD | SC / CBS | SC Code | Entity / DB | Operation Description |
|------|----------|---------|-------------|----------------------|
| - | `X31SDataBeanAccess.sendMessageString` | OneStopDataBeanAccess | - | Writes navigation metadata (screen name, screen ID) into the shared form bean — no database interaction |

This method performs **no database operations** (no C/R/U/D). It exclusively manipulates **in-memory navigation state** by writing string values into the shared data bean. No service component (SC) or database table is involved.

| CRUD | SC / CBS | SC Code | Entity / DB | Operation Description |
|------|----------|---------|-------------|----------------------|
| (none) | `X31SDataBeanAccess.sendMessageString` | (framework method) | (memory — shared form bean) | Writes next-screen navigation metadata into the session-scoped common info bean |

## 5. Dependency Trace

| # | Caller (Screen/Batch) | Call Chain (Full Path to this Method) | Terminal (SC / CRUD / Entity) |
|---|----------------------|--------------------------------------|-------------------------------|
| 1 | Screen: FUW02401 (homepage URL name acquisition application) | FUW02401SFController / JCCWebBusinessLogic dispatch → `FUW02401SFLogic.back()` | `back() → X31SDataBeanAccess.sendMessageString [SET shared-form-bean]` |

The `back()` method is called from the FUW02401 screen's controller or navigation dispatcher when the user clicks the **back button** on the confirmation screen. The FUW02401 screen (`ホームページURL名取得申込`) is the Homepage URL Name Acquisition Application — a form-based screen where users request registration of a unique URL name for their corporate homepage. No other screens or batches call this method, as it is specific to the FUW02401 workflow.

## 6. Per-Branch Detail Blocks

> The method contains no conditional branches, loops, or error-handling blocks. The control flow is linear.

**Block 1** — LINEAR `(no condition)` (L375)

> Retrieve the shared form bean from the parent class to access session-scoped navigation state.

| # | Type | Code |
|---|------|------|
| 1 | CALL | `X31SDataBeanAccess commoninfoBean = super.getCommonInfoBean()` // Retrieve shared form bean [from JCCWebBusinessLogic parent class] |

**Block 2** — LINEAR `(no condition)` (L382-383)

> Set the next screen name in the shared form bean. The framework uses this to determine which screen to render after navigation.

| # | Type | Code |
|---|------|------|
| 1 | CALL | `commoninfoBean.sendMessageString(CommonInfoCFConst.NEXT_SCREEN_NAME, X31CWebConst.DATABEAN_SET_VALUE, JFUScreenConst.SCREEN_NAME_FUW02401)` // Set next screen name [→ CONSTANT: NEXT_SCREEN_NAME = "遷移先画面名" (Next screen name)] [→ CONSTANT: DATABEAN_SET_VALUE = databean set mode] [→ CONSTANT: SCREEN_NAME_FUW02401 = "ホームページURL名取得申込" (Homepage URL Name Acquisition Application)] |

**Block 3** — LINEAR `(no condition)` (L385-386)

> Set the next screen ID in the shared form bean. The framework uses this to identify the target screen.

| # | Type | Code |
|---|------|------|
| 1 | CALL | `commoninfoBean.sendMessageString(CommonInfoCFConst.NEXT_SCREEN_ID, X31CWebConst.DATABEAN_SET_VALUE, JFUScreenConst.SCREEN_ID_FUW02401)` // Set next screen ID [→ CONSTANT: NEXT_SCREEN_ID = "遷移先画面ID" (Next screen ID)] [→ CONSTANT: DATABEAN_SET_VALUE = databean set mode] [→ CONSTANT: SCREEN_ID_FUW02401 = "FUW02401"] |

**Block 4** — RETURN `(no condition)` (L388-389)

> Return true to indicate the back navigation was handled successfully.

| # | Type | Code |
|---|------|------|
| 1 | RETURN | `return true` // Return processing result (true: normal end, false: error) [as per Javadoc] |

## 7. Glossary

| Term | Type | Business Meaning |
|------|------|------------------|
| `FUW02401SF` | Screen Module | Homepage URL Name Acquisition Application — a web form where users request registration of a unique URL name for their corporate homepage |
| `back()` | Method | Back button handler — returns to the previous screen in the multi-step form workflow |
| `JCCWebBusinessLogic` | Parent Class | Base business logic class providing common web screen infrastructure (e.g., `getCommonInfoBean()`) |
| `X31SDataBeanAccess` | Class | Shared form data bean access class — provides `sendMessageString()` and `sendMessageBoolean()` methods to write values into the session-scoped navigation context |
| `getCommonInfoBean()` | Method | Retrieves the shared common info data bean from the parent class — contains cross-screen navigation state |
| `sendMessageString()` | Method | Writes a string value into the shared form bean under a given key — used to pass navigation metadata between screens |
| `NEXT_SCREEN_NAME` | Constant | Key "遷移先画面名" (Next screen name) — identifies the next screen's display name in the shared form bean |
| `NEXT_SCREEN_ID` | Constant | Key "遷移先画面ID" (Next screen ID) — identifies the next screen's ID in the shared form bean |
| `DATABEAN_SET_VALUE` | Constant | Set mode indicator for `sendMessageString()` — specifies that the value should be written into the data bean |
| `SCREEN_NAME_FUW02401` | Constant | Value "ホームページURL名取得申込" (Homepage URL Name Acquisition Application) — the display name of screen FUW02401 |
| `SCREEN_ID_FUW02401` | Constant | Value "FUW02401" — the unique screen identifier for the homepage URL name acquisition screen |
| `JFUScreenConst` | Constant Class | Defines screen ID and screen name constants for all JFE web screens |
| `CommonInfoCFConst` | Constant Class | Defines common navigation constant keys (e.g., NEXT_SCREEN_NAME, NEXT_SCREEN_ID) used across all web screens |
| `X31CWebConst` | Constant Class | Defines common web constants (e.g., DATABEAN_SET_VALUE) used across all web screens |
| 戻ボタン | Japanese term | Back button — the UI control that navigates to the previous screen |
| ホームページURL名取得申込確認画面 | Japanese term | Homepage URL Name Acquisition Application Confirmation Screen — the final review screen before submission |
| 処理結果 | Japanese term | Processing result — the boolean return value (true: normal completion, false: error) |
| 正常終了 | Japanese term | Normal end / successful completion |
| エラー | Japanese term | Error |

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## FINAL STEP (MANDATORY)

The document has been written to `.codewiki/dd/FUW02401SFLogic/back.md` via `mcp__tools__write_file`.