# Com

## Overview

The `com` package serves as the **root Java namespace** for this project. Rather than representing a single application, it acts as the top-level package that groups two distinct sub-modules with very different purposes:

- **`com.example`** — A minimal test-fixture package designed to exercise code quality tools, import resolution, and linting rules.
- **`com.fujitsu`** — The root package for the **Futurity application platform**, a Java EE-based web application with a regional-variant architecture targeting multiple markets (Japan, US, Europe, and beyond).

These two packages share a namespace but serve fundamentally different roles: one is scaffolding for analysis tooling, the other is the structural foundation for a production-grade application platform. The `com` package itself contains no source files, classes, or methods of its own — its structure is defined entirely by its child modules.

## Sub-module Guide

### `com.example` — Test-Fixture Namespace

The `com.example` package is a **placeholder namespace** used to create reproducible test inputs for code analysis and linting. It contains no production logic. Instead, it provides minimal fixture classes that satisfy import resolution so that other test units (such as JSP files exercising language-level import rules) can compile without errors.

The only documented child under `example` is `bugca002`, which provides a `KnownClass` stub consumed by a JSP test file. The `KnownClass` has an empty `execute()` method — intentionally minimal so it satisfies the compiler without introducing noise into the rule-under-test.

### `com.fujitsu` — Futurity Application Platform

The `com.fujitsu` package is the root for the **Futurity platform**, a Java EE web application structured around a **regional-variant architecture**. Each market deployment (Japan, US, Europe) gets its own sub-package that customizes lifecycle initialization, request encoding, and deployment configuration while sharing a common application core.

The primary documented child is `futurity`, which contains the platform's web tier (`com.fujitsu.futurity.web`). Under the web tier, the `x33` subpackage represents the Japanese-market variant, providing:

- **`X33AppContextListener`** — A servlet context listener registered in `web.xml` that serves as the entry point for x33-specific application bootstrapping during container startup.
- **`X33JVRequestEncodingSjisFilter`** — A servlet filter that intercepts every incoming HTTP request. Its name indicates an original intent to enforce Shift JIS (`MS932`) character encoding on request parameters, a standard requirement for legacy Japanese enterprise applications.

**How the sub-modules relate**

While `com.example` and `com.fujitsu` share no code-level dependencies, they share an architectural theme: **both are scaffolding**. `com.example` provides structural scaffolding for test tooling (minimal types that resolve imports), while `com.fujitsu` provides structural scaffolding for application code (class declarations and deployment descriptor wiring with deferred implementation). This suggests the project is in an early phase where infrastructure and test fixtures are established before substantive application logic is added.

## Key Patterns and Architecture

### Regional-Variant Package Pattern

The Futurity platform (`com.fujitsu.futurity`) uses a variant package pattern where each market deployment gets its own sub-package with identically named classes but region-specific behavior. The `x33` package (Japanese variant) implies sibling packages like `x33us` (US) and `x33eu` (Europe) following the same structure. Each variant can define its own character encoding, localization hooks, and startup behavior while sharing the broader platform logic.

### Stub-as-Dependency Pattern

Both sub-modules employ a **stub-as-dependency** approach:

1. **In `com.example`**: Classes like `KnownClass` are intentionally empty, designed solely to satisfy the compiler and enable import resolution for test units.
2. **In `com.fujitsu`**: Both the listener (`X33AppContextListener`) and filter (`X33JVRequestEncodingSjisFilter`) implement standard Java EE interfaces but contain no active runtime logic.

This pattern signals either deferred feature development, logic migrated to a higher layer, or variant scaffolding where the skeleton is in place before implementation.

### Deployment Descriptor–Driven Wiring

All component registration in the Futurity platform happens through `web.xml` and its full-deployment variant `web-full.xml`. There is no annotation-based registration (e.g., `@WebListener`, `@WebFilter`) or Java-based configuration visible. The presence of `web-full.xml` suggests deployment-profile overrides for different environments or deployment profiles.

### Character Encoding by Market

The filter naming convention (`X33JVRequestEncodingSjisFilter`) reveals that character encoding is a **first-class concern** scoped per variant. The Japanese variant targets Shift JIS (`MS932`), while other variants would target their market's standard encoding. This per-variant encoding strategy is critical for legacy Japanese enterprise applications where request body parsing must match the encoding of incoming form data.

### Architecture Diagram

The following diagram shows how the two sub-modules and their components relate:

```mermaid
flowchart TD
    subgraph Com[com - Root Java Namespace]
        subgraph Example[com.example - Test Fixture Package]
            Bugca002["bugca002
(import resolution fixture)"]
        end
        subgraph Fujitsu[com.fujitsu - Fujitsu Platform]
            subgraph Futurity[com.fujitsu.futurity - Application Platform]
                subgraph Web[com.fujitsu.futurity.web - Web Tier]
                    subgraph X33[x33 - Japanese Market Variant]
                        Listener["X33AppContextListener
(lifecycle bootstrapping)"]
                        Filter["X33JVRequestEncodingSjisFilter
(request encoding)"]
                    end
                end
            end
        end
    end

    WebXML["web.xml / web-full.xml
(deployment descriptors)"] -->|registers| Listener
    WebXML -->|registers and maps| Filter
    Listener -.->|bootstraps| Container["Servlet Container"]
    Filter -.->|intercepts requests| Pipeline["Filter Chain"]
    Example -.->|consumed by| Jsp["BugCa002 JSP
(test fixture)"]
```

## Dependencies and Integration

### External Dependencies

- **`javax.servlet`** — The standard Java Servlet API provides all interfaces used by the Futurity web tier: `Filter`, `FilterConfig`, `FilterChain`, `ServletRequest`, `ServletResponse`, and `ServletContextListener`. This is the sole external dependency detected in the current index.

### Internal Dependencies

- **`web.xml` / `web-full.xml`** — Primary and full-deployment descriptors that register the Futurity web tier components.
- **`com.example.bugca002`** — Consumed by `BugCa002Language Before Import.jsp` to satisfy import resolution for a code quality test.

### Cross-Module Integration

No cross-module relationships were detected between `com.example` and `com.fujitsu`. They operate in completely separate concerns:

- **`com.example`** integration is with the linting and code quality tooling — it provides stable, resolvable types for test units that validate specific rule behaviors.
- **`com.fujitsu`** integration, when fully implemented, would occur through `ServletContext` attributes (shared state set by the listener), global servlet container configuration (e.g., `server.xml`), and sibling regional variant packages.

### Dependency Graph

```mermaid
flowchart LR
    Jsp["BugCa002 JSP"] -->|imports| KnownClass["KnownClass
com.example.bugca002"]
    WebXML["web.xml"] -->|registers| Listener["X33AppContextListener"]
    WebXML -->|maps| Filter["X33JVRequestEncodingSjisFilter"]
    Listener -->|depends on| ServletAPI["javax.servlet API"]
    Filter -->|depends on| ServletAPI
```

## Notes for Developers

### Working with `com.example`

- **This is test fixture code, not production code.** The classes here are stubs and placeholders. Adding business logic to `KnownClass` is unlikely to be the right direction unless you are explicitly extending the `bug-ca-002` test scenario.
- **If a new sub-package is needed**, follow the existing naming convention — use a `bugcaXXX` format where `XXX` corresponds to the code quality rule or lint scenario being tested. Each new sub-package should provide a minimal, well-named class that the consuming test unit imports.
- **The actual rule logic** for `bug-ca-002` lives in the lint/config rules that reference `KnownClass`, not in the class itself. To extend or fix the rule, look at the lint configuration and test harness that drive the `bugca002` fixture.

### Working with `com.fujitsu`

- **The module is currently skeletal.** Neither the filter nor the listener contains active runtime logic. Before making changes, verify whether encoding or initialization logic has been migrated to the servlet container configuration (e.g., `server.xml`) or sibling regional packages.
- **The filter is safe to remove or deprecate.** Since `X33JVRequestEncodingSjisFilter.doFilter()` passes requests through unmodified, removing it from `web.xml` has no runtime impact unless deployment descriptor ordering is significant.
- **To implement the filter**, the standard approach is:

```java
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
        throws IOException, ServletException {
    req.setCharacterEncoding("MS932"); // Shift JIS for Japanese variant
    chain.doFilter(req, res);
}
```

Alternatively, configure the servlet container's `URIEncoding` attribute in `server.xml` for a global approach.

- **The listener should implement `ServletContextListener`** when lifecycle logic is added. The `contextInitialized()` method is the natural place to bootstrap x33-specific resources.
- **To add a new regional variant**, mirror the `x33` structure: create a sub-package under `web`, implement a character-encoding filter appropriate to the market, and register both the filter and listener in `web.xml`.
- **No source files are currently indexed** at the parent package level for either sub-module. The module state is entirely defined by its child packages and their stub classes.

### General

- Both sub-modules are in a **scaffolding state** — structure and wiring are in place, but no substantive logic exists at this layer. This is consistent with a project in early development or mid-migration.
- The `com` package itself has no indexed source files, classes, or methods. All activity flows through its child sub-modules.
- The project follows **traditional Java EE conventions** (XML deployment descriptors, standard servlet interfaces) with no Spring annotations, Java-based configuration, or dependency injection frameworks detected.