# Business Logic — Items.find() [8 LOC]

| Field | Value |
|-------|-------|
| Fully Qualified Name | `com.fujitsu.futurity.bp.custom.common.Items` |
| Layer | Common Component (Package: `com.fujitsu.futurity.bp.custom.common`) |
| Module | `common` (Package: `com.fujitsu.futurity.bp.custom.common`) |

## 1. Role

### Items.find()

The `Items.find()` method is a **generic linear search utility** that locates the first element in a collection matching a user-supplied predicate condition. It implements the **functional query pattern** — accepting a `Predicater<I>` callback so callers can define arbitrary filtering logic without exposing iteration internals. This method is the "find-first" equivalent of Java 8's `stream().filter().findFirst()`, adapted for the pre-Java 8 codebase. In the broader system, it serves as a **shared common component** referenced by over 56 callers across screen processing, batch processing, and data validation modules. It enables callers to extract a single item — such as a configuration record, a matching data row, or a specific bean field — from a list without manual loop boilerplate. The method is part of an internal utility class `Items` that also provides `select()`, `exist()`, `each()`, and `map()`, forming a mini-collection-processing DSL used throughout the Futurity business platform.

## 2. Processing Pattern (Detailed Business Logic)

```mermaid
flowchart TD
    START(["find(in, predicater)"])
    LOOP["for (I item : in)"]
    EVAL["predicater.evaluate(item)"]
    MATCH{"Match found?"}
    RET_ITEM["return item"]
    RET_NULL["return null"]
    END_NODE(["Return"])

    START --> LOOP
    LOOP --> EVAL
    EVAL --> MATCH
    MATCH -- "true" --> RET_ITEM
    MATCH -- "false" --> LOOP
    RET_ITEM --> END_NODE
    LOOP --> RET_NULL
    RET_NULL --> END_NODE
```

**Processing flow:**

1. **Entry:** The method receives a list `in` of type `ArrayList<I>` and a `Predicater<I>` predicate callback.
2. **Iteration:** It iterates through each element of the list sequentially from the first to the last.
3. **Evaluation:** For each element, it invokes `predicater.evaluate(item)`, delegating the matching logic to the caller-provided predicate implementation.
4. **Match (true):** If the predicate returns `true`, the current element is immediately returned as the result. The search terminates on the first match.
5. **Match (false):** If the predicate returns `false`, iteration continues to the next element.
6. **Exhaustion:** If the loop completes without any match, `null` is returned.

This is a **short-circuiting** operation — once the first matching element is found, no further elements are examined.

## 3. Parameter Analysis

| No | Parameter Name | Type | Business Description |
|----|---------------|------|---------------------|
| 1 | `in` | `ArrayList<I>` | A collection of items to search through. In practice, callers typically pass `ArrayList<HashMap<String, String>>`, `ArrayList<HashMap<String, Object>>`, or other domain-specific lists. For example, callers pass lists of configuration data rows, product service type codes, address records, or bean values. The specific generic type `I` depends on the caller's use case. |
| 2 | `predicater` | `Predicater<I>` | A functional interface callback that encodes the filtering condition. The caller implements `boolean evaluate(I input)` to define what constitutes a match. Common predicate implementations include `TextFilter` (matches a key-value pair in a `HashMap<String, String>`) and `ObjectFilter` (matches a key-value pair in a `HashMap<String, Object>`). This enables flexible search criteria such as "find the row where service type equals '01'" or "find the record where the contract status code equals '1'." |

**External state:** No instance fields or external state are read by this method. It is fully stateless and pure — its output depends solely on its inputs.

## 4. CRUD Operations / Called Services

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

| CRUD | SC / CBS | SC Code | Entity / DB | Operation Description |
|------|----------|---------|-------------|----------------------|
| R | `Predicater.evaluate` | - | - | Reads/delegates to caller-provided predicate to evaluate each element against the matching condition. This is a read-only logical operation — no database access occurs within this method itself. |

**CRUD Analysis:** This method performs **no direct database operations**. It is a pure in-memory collection utility. The `Predicater.evaluate()` call is a read-only predicate evaluation — the actual data source (database, file, or application bean) was populated by the caller before this method was invoked.

| CRUD | SC / CBS | SC Code | Entity / DB | Operation Description |
|------|----------|---------|-------------|----------------------|
| - | `Predicater.evaluate` | - | - | Delegates to caller-provided predicate to evaluate each element. Read-only, no DB access. |

## 5. Dependency Trace

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

No screen/batch entry points found within 8 hops. Direct callers found: 56 methods.
Terminal operations from this method: `evaluate` [-], `evaluate` [-], `evaluate` [-], `evaluate` [-], `evaluate` [-]

Trace who calls this method and what this method ultimately calls.

| # | Caller (Screen/Batch) | Call Chain (Full Path to this Method) | Terminal (SC / CRUD / Entity) |
|---|----------------------|--------------------------------------|-------------------------------|
| 1 | `JCHbatSeikyKaknoBusinessUtil` (Batch) | `makeChkdigtBfCd()` -> `Items.find` | `evaluate` [-] |
| 2 | `JKKSmtvRcvFile` (Batch — Receive file) | `receiveContentAtLine()` -> `Items.find` | `evaluate` [-] |
| 3 | `JKKTjgsAreaIfAddRsltRcvFile` (Batch — Receive file) | `receiveContentAtLine()` -> `Items.find` | `evaluate` [-] |
| 4 | `JBSbatACPointHikiate` (Batch) | `isDummyData()` / `isErrorData()` / `isErrorData2()` / `isErrorData3()` -> `Items.find` | `evaluate` [-] |
| 5 | `JBSbatCN050TelnoHktHkListKkRsv` (Batch) | `getReceiveFileName()` -> `Items.find` | `evaluate` [-] |
| 6 | `JBSbatKKAtchakuYoksiChk` (Batch) | `cutKyohiRsn()` -> `Items.find` | `evaluate` [-] |
| 7 | `JBSbatKKSvctkareaUpd` (Batch) | `getStringValue()` -> `Items.find` | `evaluate` [-] |
| 8 | `JBSbatTUTdisInfoRnkiFileSaksei` (Batch) | `editKeisaiNmKanji()` -> `Items.find` | `evaluate` [-] |
| 9 | `JFUSplitAddressInfoCC` (CC — Address split) | `editChomeOutMsg()` / `editStateOutMsg()` -> `Items.find` | `evaluate` [-] |
| 10 | `JFUSplitAddressInfoChomeCC` (CC — Address split) | `editStateOutMsg()` -> `Items.find` | `evaluate` [-] |
| 11 | `JCHCommonBarcodeEdit` (CC — Barcode) | `chgEijiAlpha()` / `makeChkdigtBfCd()` -> `Items.find` | `evaluate` [-] |
| 12 | `JSYejbEKK0081B560TPDA` (Screen TPDA) | `SetSqlParam()` -> `Items.find` | `evaluate` [-] |
| 13 | `JSYejbEKK0341B530TPDA` (Screen TPDA) | `SetSqlParam()` -> `Items.find` | `evaluate` [-] |
| 14 | `JSYejbEKK0341B531TPDA` (Screen TPDA) | `SetSqlParam()` -> `Items.find` | `evaluate` [-] |
| 15 | `JFUGetTnmtType` (CC — Transport type) | `endElement()` -> `Items.find` | `evaluate` [-] |

**Summary of caller distribution:**
- **Screen processing** (TPDA classes `JSYejbEKK*`): Used to locate specific parameter values for SQL statement preparation.
- **Batch processing** (`JBSbat*`, `JKKSmtvRcvFile`, `JKKTjgsAreaIfAddRsltRcvFile`): Used for data validation (isDummyData, isErrorData), file name extraction, and error code filtering.
- **Common components** (`JFUSplitAddressInfo*`, `JCHCommonBarcodeEdit`, `JFUGetTnmtType`): Used for address field lookups, barcode editing, and transport type determination.
- **Form logic** (`FUW00144SFLogic`, `FUW10901SFLogic`, `FUW11101SFLogic`, `FUW00906SFLogic`, `FUW00940SFLogic`, `FUW00944SFLogic`): Used for bean value retrieval, parameter management, and service type checks.

## 6. Per-Branch Detail Blocks

**Block 1** — [FOR] `(for each item in in)` (L16654)

> Iterate through every element in the input collection sequentially. The generic type `I` ensures type safety across heterogeneous callers (HashMap, domain beans, etc.).

| # | Type | Code |
|---|------|------|
| 1 | SET | `I item : in` // Iterate each element from the input ArrayList |

**Block 1.1** — [IF] `(predicater.evaluate(item))` (L16655)

> Invoke the caller-provided predicate on the current element. This is a delegation — the actual comparison logic is defined by the caller's `Predicater` implementation (e.g., `TextFilter`, `ObjectFilter`, or a custom anonymous class).

| # | Type | Code |
|---|------|------|
| 1 | CALL | `predicater.evaluate(item)` // Delegate matching logic to caller's predicate |

**Block 1.1.1** — [IF — Match found] `(predicate returns true)` (L16656)

> A matching element was found. This is a short-circuit exit — return immediately without examining remaining elements.

| # | Type | Code |
|---|------|------|
| 1 | RETURN | `return item;` // Return first matching element |

**Block 1.2** — [ELSE] `(predicate returns false)` (implicit, L16655)

> The current element does not match the predicate. Loop continues to the next element. No explicit action needed.

**Block 2** — [RETURN] `(end of loop — no match)` (L16658)

> The entire collection was traversed without finding any matching element. Return null to signal no match.

| # | Type | Code |
|---|------|------|
| 1 | RETURN | `return null;` // No matching element found |

## 7. Glossary

| Term | Type | Business Meaning |
|------|------|------------------|
| `Predicater` | Interface | Functional interface defining a boolean test (`evaluate`) on a single input element. Used to encode arbitrary filtering conditions. |
| `Transformer` | Interface | Functional interface that transforms an input of type `I` into an output of type `O`. Part of the same utility class. |
| `Closure` | Interface | Functional interface representing an operation that accepts one input and returns no result. Used for side-effect operations like `add` to a result list. |
| `Items` | Class | Internal generic collection utility class providing `find`, `select`, `exist`, `each`, and `map` methods — a pre-Java 8 functional-style collection DSL. |
| `TextFilter` | Class | A `Predicater<HashMap<String, String>>` implementation that matches a `HashMap` entry by key-value pair. Used for string-based lookups. |
| `ObjectFilter` | Class | A `Predicater<HashMap<String, Object>>` implementation that matches a `HashMap` entry by key-object value. Used for object-based lookups. |
| `Sequencer` | Class | A `Transformer` that assigns sequential numbers to HashMap entries by key. Used for auto-incrementing ID generation. |
| DEFAULT_ARRAY_SIZE | Constant | Default initial capacity of 100 for new ArrayList instances created by utility methods. |
| DEFAULT_HASH_SIZE | Constant | Default initial capacity of 50 for new HashMap instances created by utility methods. |
| TPDA | Acronym | Screen data access layer class — the presentation-tier data access component in the Futurity architecture. |
| SFLogic | Acronym | Screen Form Logic — the form-level business logic component that manages bean data. |
| CBS | Acronym | Central Business System — the core business processing layer. |
| CC | Acronym | Common Component — shared utility classes used across multiple modules. |
| FTTH | Business term | Fiber To The Home — fiber-optic broadband internet service in the NTT communications domain. |
| HashMap | Data structure | Java associative array used as the primary data transfer object, carrying key-value pairs representing database records or form fields. |