# Getting Started

## What This Project Does
This repository is a small Java codebase made up of simple domain-style classes rather than a full application framework. The code looks like a mix of lightweight service objects, data holders, and label-oriented test fixtures. There is no obvious framework wiring or application bootstrap, so the fastest way to understand it is to read the core behavior classes first and then scan the field-heavy examples.

## Recommended Reading Order
1. [Overview](../overview.md) — start here for the big-picture summary of the repository.
2. [Repository tree](../tree.json) — use this to confirm what lives in the root module and how the files are grouped.
3. [Root guide](../root.md) — the root module is the whole codebase, so this is the main navigation page for source files.

After that, read the source files in this order:
1. [`OrderProcessor`](../../src/main/java/OrderProcessor.java) — clearest behavior-oriented entry point.
2. [`ProductService`](../../src/main/java/ProductService.java) — a second, simpler service-style class.
3. [`LargeFieldMap`](../../src/main/java/LargeFieldMap.java) — useful for understanding field naming and mapping patterns.
4. [`LargeBusinessLabelClass`](../../src/main/java/LargeBusinessLabelClass.java) — shows the label-heavy style used in the project.
5. [`MixedLabelClass`](../../src/main/java/MixedLabelClass.java), [`PartialLabelEntity`](../../src/main/java/PartialLabelEntity.java), [`EucJpClass`](../../src/main/java/EucJpClass.java), and [`MultiPattern`](../../src/main/java/MultiPattern.java) — scan these to see the remaining variations.
6. [`A`](../../src/main/java/A.java) — minimal placeholder class.

## Key Entry Points
There are no highly connected classes in this repository, so the best starting points are the two behavior-oriented classes:

- [`OrderProcessor`](../../src/main/java/OrderProcessor.java) — contains `createOrder(String orderId)`, which is the closest thing to a business operation in the codebase.
- [`ProductService`](../../src/main/java/ProductService.java) — exposes a simple getter over an internal product identifier.

If you only have time to read two files, read those first.

## Project Structure
The repository is organized as a flat set of Java classes under `src/main/java`. There are no visible submodules or nested package layers in the indexed tree, so each file stands mostly on its own.

```mermaid
flowchart TD
Root["Repository"] --> JavaSrc["src/main/java"]
JavaSrc --> OrderProcessor["OrderProcessor.java"]
JavaSrc --> ProductService["ProductService.java"]
JavaSrc --> LargeBusinessLabelClass["LargeBusinessLabelClass.java"]
JavaSrc --> LargeFieldMap["LargeFieldMap.java"]
JavaSrc --> MixedLabelClass["MixedLabelClass.java"]
JavaSrc --> PartialLabelEntity["PartialLabelEntity.java"]
JavaSrc --> EucJpClass["EucJpClass.java"]
JavaSrc --> MultiPattern["MultiPattern.java"]
JavaSrc --> A["A.java"]
```

## Configuration
No dedicated build or runtime configuration files were visible in the indexed repository snapshot. That usually means one of two things: either configuration lives outside the scanned subset, or the project is intended as a small core library / fixture set with minimal setup.

What to check next if you need runtime details:
- Build files such as `pom.xml`, `build.gradle`, or `settings.gradle`
- Java version settings if present in wrapper or CI files
- Any resource or properties files that may describe encoding or label behavior

## Common Patterns
A few patterns repeat across the source files:

- **Simple, direct methods** — methods tend to return stored values or echo input with little extra logic.
- **Field-holder classes** — many classes are mostly collections of private fields.
- **Label/comment-heavy code** — several classes include Japanese comments or mixed labels, which suggests the code may be used for mapping, encoding, or documentation-style examples.
- **Low coupling** — classes appear independent rather than wired together through a service container or framework.

## Where to Go Next
Once you have read the starting files, move outward from behavior to structure:
1. Confirm the build or test setup from the repository root.
2. Scan the field-heavy classes to understand naming conventions and encoding expectations.
3. Use the root guide and source files as your reference map when exploring the rest of the project.