# Getting Started

## What This Project Does

This is a Java-based business application framework focused on entity modeling and order processing. It provides domain classes for managing orders, products, and business data with support for multi-language (Japanese/English) field labeling. The codebase is primarily used to exercise and validate field label parsing, localization, and entity mapping capabilities.

## Recommended Reading Order

1. **OrderProcessor** — Read this first. It's the most documented class with Javadoc and represents the core business workflow (order creation). Start here to understand what the system does.
2. **ProductService** — A minimal entity with a getter method. Shows the basic pattern for simple domain objects.
3. **LargeFieldMap** — Demonstrates the mapping entity pattern used across the codebase, with a realistic set of business fields.
4. **LargeBusinessLabelClass** — A large-scale entity (50 fields) that exercises the label parsing infrastructure. Useful for understanding how bulk data structures are modeled.
5. **MixedLabelClass** / **PartialLabelEntity** — Edge-case entities that test mixed labeling patterns (Japanese, English, and unlabeled fields in the same class).
6. **MultiPattern** — Shows a class with mixed comment annotation styles alongside labeled fields.
7. **EucJpClass** — A simple user/org entity that illustrates basic encoding and labeling patterns.

## Key Entry Points

| Class | Purpose |
|---|---|
| [OrderProcessor](src/main/java/OrderProcessor.java) | Main business entry point — processes orders for the system. Contains the only Javadoc in the codebase. |
| [ProductService](src/main/java/ProductService.java) | Product domain object with a basic getter method. Smallest working entity. |
| [LargeFieldMap](src/main/java/LargeFieldMap.java) | Service interface mapping entity with ~10 business fields. The largest fielded class used for mapping scenarios. |
| [LargeBusinessLabelClass](src/main/java/LargeBusinessLabelClass.java) | A 50-field entity used to test label parsing at scale. |
| [MixedLabelClass](src/main/java/MixedLabelClass.java) | Demonstrates mixed labeling (Japanese + English + no label) in a single class. |

## Project Structure

```
src/
  main/
    java/
      A.java                   -- Placeholder / empty class
      EucJpClass.java          -- User/org entity (Japanese labels, EUC-JP encoding)
      LargeBusinessLabelClass.java -- 50-field entity for label stress testing
      LargeFieldMap.java       -- Service IF mapping entity
      MixedLabelClass.java     -- Mixed label styles (JP/EN/no-label)
      MultiPattern.java        -- Mixed comment annotation patterns
      OrderProcessor.java      -- Core order processing logic
      PartialLabelEntity.java  -- Partially labeled entity (alternating labels)
      ProductService.java      -- Simple product entity with getter
```

There are no sub-modules. All source lives in a flat `src/main/java/` directory. No configuration files (XML, YAML, properties) are present — this is a pure source code project.

## Configuration

This project has no configuration files checked in. The classes themselves serve as the primary artifact. If configuration is needed in the future, standard locations to look for or add:

- `pom.xml` — Maven build configuration (not present)
- `src/main/resources/` — Application resource files (not present)

## Common Patterns

### Field Labeling Convention

All fields use the pattern `private String fieldName = ""` with an inline comment for the label:

```java
private String userId = ""; // ユーザーID
```

Labels are written in Japanese, with some classes mixing English comments.

### Comment Styles

The codebase uses three comment styles — be aware when reading:

1. **Javadoc** — Used only in `OrderProcessor.java` (public method documentation).
2. **Inline `//` comments** — The dominant style, used for field labels throughout.
3. **Annotation markers** — `MultiPattern.java` uses `// ANK-4494-00-00 ADD START / END` style markers to delineate code blocks.

### Entity Pattern

All business classes follow a simple POJO pattern:

- `private String` fields with default empty string initialization
- No constructors defined (default constructor used)
- Simple getter methods where applicable (e.g., `getProduct()`)
- No inheritance or interfaces

### Japanese Localization

Several classes contain Japanese field labels (ユーザーID, 組織コード, 状態区分, etc.). If you are editing these files, be aware that the codebase supports multi-byte character encoding (EUC-JP). When adding new fields or modifying labels, preserve the encoding.

### No External Dependencies

This project has no external libraries, no build system files, and no dependencies. It is a standalone collection of Java source files.