# Com / Fujitsu

## Overview

The `com.fujitsu` package area represents Fujitsu-branded modules within the codebase. At present, it contains a single child module — **Futurity** — which is a top-level Java EE enterprise application scaffold targeting Japanese-language users.

This area is greenfield: no source files are yet indexed at the `com.fujitsu` package level itself, and the Futurity module exists primarily as structural scaffolding. The web-layer stubs in `com.fujitsu.futurity.web` identify integration touchpoints (a Shift-JIS encoding filter and a servlet context listener) and wire them into a deployment descriptor, but neither component contains operational logic. This approach suggests a deliberate design process where the system's external interface was mapped and configured before business logic was implemented.

The Futurity application appears to serve as a Japanese-language web platform, with character encoding (Shift-JIS / CP932) as a core early requirement. Its architecture follows standard Java EE servlet conventions with no framework-specific annotations, relying entirely on container-managed lifecycle and XML-based deployment configuration.

## Sub-module Guide

The `com.fujitsu` package currently contains one documented child module:

### com.fujitsu.futurity -- Futurity Application

**Package:** `com.fujitsu.futurity`

The Futurity module is a Japanese enterprise web application built on the Java EE servlet stack. It is organized around a web-first architecture where the HTTP surface area was defined and wired into the servlet container before downstream business components were implemented.

**Child sub-modules:**

- **`com.fujitsu.futurity.web`** -- The application's web entry point, providing servlet-tier infrastructure for request handling, character encoding, and lifecycle management. This is where all HTTP interaction with the system flows.
- **`com.fujitsu.futurity.web.x33`** -- The first concrete feature area within the web layer. It defines two stubbed components: an encoding filter (`X33JVRequestEncodingSjisFilter`) and a context listener (`X33AppContextListener`), both registered in the deployment descriptor but awaiting implementation.

**How they relate:** Futurity is the umbrella application; the `web` package is its HTTP-facing tier; `x33` is the first feature within that tier. The relationship is structural — the deployment descriptor (`web-full.xml`) binds them together, defining lifecycle ordering and request routing before any implementation code exists.

## Key Patterns and Architecture

### Stub-First Scaffolding

The dominant architectural decision in this area is scaffold-first development. The X33 filter and listener are no-ops that exist solely to claim their positions in the servlet container's lifecycle and filter chain. This signals that the design phase identified integration points (character encoding, application-scoped resources) before the implementation phase began, allowing downstream work to proceed once the web-layer contract was established.

### Container-Managed Lifecycle

All components in the web layer follow the Java EE servlet lifecycle. The container manages instantiation, lifecycle callbacks, and request dispatch. Components are singletons, shared across all requests, which imposes strict thread-safety discipline on any future implementation.

### Deployment-Driven Configuration

Configuration is externalized into `web-full.xml`, the canonical descriptor for all web-layer components. No annotations are used — every filter mapping, listener registration, and servlet definition lives in XML. This keeps the code framework-agnostic and fully container-managed, but makes ordering and dependency inspection a configuration-level concern.

### Request Encoding Strategy

The X33 filter's purpose is to intercept incoming requests and set character encoding (Shift-JIS / CP932) before any downstream component reads request data. Because encoding must be established before the request body is consumed, filter ordering in `web-full.xml` is critical — the X33 filter must appear before any component that parses form parameters, request bodies, or JSON payloads.

#### Module Architecture

```mermaid
flowchart TD
    SRC["com.fujitsu.futurity
Parent Package"] --> WEB["com.fujitsu.futurity.web
Web Entry Point"]
    WEB --> WEB_DESC["Servlet-tier infrastructure:
request handling, encoding,
lifecycle management"]
    WEB --> X33["com.fujitsu.futurity.web.x33
X33 Feature Web Layer"]
    X33 --> FILTER["X33JVRequestEncodingSjisFilter
Shift-JIS encoding filter (stub)"]
    X33 --> LISTENER["X33AppContextListener
Lifecycle listener (stub)"]
    WEB --> DESC["web-full.xml
Deployment Descriptor"]
    DESC --> WEB
    DESC --> X33
    SRC --> DESC
```

#### Request Lifecycle

```mermaid
flowchart LR
    CLIENT["HTTP Client"] -->|request| WC["Web Container"]
    WC -->|startup| LST["X33AppContextListener
.contextInitialized()"]
    LST -->|prepares| RES["X33 resources /
services in ServletContext"]
    WC -->|HTTP request| WEB["web-full.xml
filter mapping"]
    WEB -->|dispatches| FLT["X33JVRequestEncodingSjisFilter
.doFilter()"]
    FLT -->|passes through| CHN["downstream
filter chain"]
    WC -->|shutdown| LSH["X33AppContextListener
.contextDestroyed()"]
    LSH -->|releases| RES
```

## Dependencies and Integration

### External Dependencies

| Dependency | Purpose |
|------------|---------|
| `javax.servlet.Filter` | Implemented by the X33 encoding filter for request processing |
| `javax.servlet.ServletContextListener` (expected) | To be implemented by the X33 context listener for lifecycle management |
| `web-full.xml` | Deployment descriptor registering all web-layer components |

### Internal Dependencies

No inbound callers have been detected in the codebase index — no other Java packages import or reference classes from `com.fujitsu.futurity` or its sub-packages. This confirms that the web module is either newly introduced or operating in isolation. The filter is invoked purely through XML-based servlet container configuration rather than Java-level references.

### Integration Points (Planned)

When fully implemented, the web module will integrate through:

- **Filter chain:** The X33 filter delegates to the downstream chain, eventually reaching X33's servlets, controllers, or other web components (not yet present).
- **ServletContext:** The context listener will share application-scoped attributes and resources across components via the standard `ServletContext` mechanism.
- **Deployment descriptor:** All wiring flows through `web-full.xml`.

## Notes for Developers

1. **Both classes are stubs.** Neither the filter nor the listener contains operational logic. This is a scaffolded module awaiting implementation, not a bug.

2. **Implementing the filter:** When adding encoding logic, cast the `ServletRequest` to `HttpServletRequest`, call `setCharacterEncoding("SJIS")` (or `"CP932"`) before `chain.doFilter()`, and consider making the encoding configurable via a servlet init-param or context-param rather than hardcoding it.

3. **Implementing the listener:** Add `javax.servlet.ServletContextListener` as an implemented interface and provide `contextInitialized` and `contextDestroyed` methods. Coordinate with the X33 team on initialization ordering and resource lifecycle to avoid conflicts with other application components.

4. **Filter ordering is critical.** If the filter handles encoding, it must appear early in the `<filter-mapping>` order in `web-full.xml`, before any component that reads request parameters.

5. **Thread safety.** As singleton container-managed components, both classes are instantiated once and handle all requests on shared instances. Any future state must be read-only after initialization, or protected by synchronization.

6. **No other module depends on this package.** Changes to these classes have limited blast radius within the existing codebase.

7. **Encoding choice matters for Japanese locales.** Verify whether the application requires Shift-JIS (`"SJIS"` / `"CP932"`) or has migrated to UTF-8. Modern applications typically use UTF-8, but legacy Japanese enterprise systems often require Shift-JIS for form data compatibility.

8. **This is a greenfield module.** The absence of indexed source files and classes suggests the source files are either not yet committed or are very small stubs. Developers working in this area should expect to build functionality from the scaffolding upward.