# Com / Fujitsu

## Overview

The `com.fujitsu` package serves as the root namespace for Fujitsu-related Java EE applications within this codebase. Currently, it contains a single web application — **Futurity** — which is a browser-based multi-market application with locale-specific variants (most notably the Japanese X33 variant).

At this level, the package has no direct source files, classes, or methods indexed. Its purpose is organizational: it groups Fujitsu's application code under a shared root package prefix. The actual application logic, data models, and service implementations reside in downstream packages (such as `com.fujitsu.futurity`) rather than in the root itself.

This is a relatively empty organizational tier — the real architectural activity happens one level deeper, inside the `futurity` subpackage.

## Sub-module Guide

### `futurity` — the Fujitsu Futurity web application

The `futurity` subpackage is the sole documented child of this package and represents a full Java EE web application. It provides a servlet-tier request-processing infrastructure for a browser-based user interface, with a focus on internationalization and locale-aware configuration.

**Key characteristics of the futurity subpackage:**

- **Multi-market design**: The application supports locale-specific variants. The Japanese variant (X33) is the best-documented, with Shift-JIS character encoding support through servlet filters and lifecycle listeners.
- **Layered architecture**: The web tier sits at the HTTP boundary as the entry point for all browser requests, with actual business logic and data access in downstream packages not indexed at this level.
- **Scaffolding state**: Many components in `futurity` are scaffolded — their class structures and integration points are correctly defined (e.g., implementing `javax.servlet.Filter`), but their implementation bodies are deferred or no-op. This is common in localization work where the framework is set up before locale-specific logic is fully specified.

**How `futurity` fits in**: This subpackage is the only concrete piece of code under the `com.fujitsu` umbrella. It occupies the HTTP boundary of the overall system and acts as the configurable gateway through which browser requests enter the application. All request processing infrastructure, encoding normalization, and locale configuration for Fujitsu's web applications funnels through this subpackage.

## Key Patterns and Architecture

### Module Hierarchy

```mermaid
flowchart TD
    Fujitsu["com.fujitsu (root namespace)"] --> Futurity["com.fujitsu.futurity<br/>Futurity web application"]
    Futurity --> Web["web subpackage<br/>HTTP request boundary"]
    Web --> X33["x33 subpackage<br/>Japanese locale variant"]
    X33 --> Filter["filter subpackage<br/>X33JVRequestEncodingSjisFilter"]
    X33 --> Listener["listener subpackage<br/>X33AppContextListener"]
```

### Request Processing Pipeline

Requests from browsers enter through the servlet container, pass through the X33 filter for encoding normalization, and are dispatched into downstream business logic. This is the standard Java EE filter-chain pattern:

```mermaid
sequenceDiagram
    participant Browser as "Browser"
    participant Container as "Servlet Container"
    participant Filter as "X33 Filter"
    participant Chain as "FilterChain"
    participant Servlet as "Target Servlet"
    Browser->>Container: HTTP request
    Container->>Filter: doFilter
    Filter->>Chain: chain.doFilter
    Chain->>Servlet: deliver request
    Servlet-->>Filter: return response
    Filter-->>Browser: respond to client
```

### Architectural Layering

```mermaid
flowchart TD
    Client["Browser / Client"] --> Dispatcher["Servlet Dispatcher"]
    Dispatcher --> X33Filter["X33 Filter"]
    X33Filter --> TargetServlet["Target Servlet"]
    TargetServlet --> Business["Business Logic"]
    Business --> Service["Service Layer"]
```

The filter acts as a configurable gateway at the outermost layer, enforcing encoding or locale constraints before data enters the application's core processing pipeline. Each subsequent layer handles progressively higher-abstraction concerns.

## Dependencies and Integration

### Inbound Dependencies

| Dependency | Role |
|---|---|
| Deployment descriptor (`web-full.xml`) | Registers the X33 servlet filter with the servlet container, defining URL patterns and init parameters. |

### Outbound Dependencies

| Dependency | Role |
|---|---|
| `javax.servlet.*` | Standard Java EE Servlet API — the filter interface, request/response types, and listener interface used by both the X33 filter and application context listener. |

### Cross-module Relationships

The `com.fujitsu.futurity` package is a child of `com.fujitsu`, and its `web` subpackage is the HTTP boundary of the Futurity application. Sibling packages for other locales (e.g., an English-language variant) may exist alongside X33, each with their own encoding and lifecycle configuration. The X33 filter delegates to downstream servlets and controllers that handle the application's actual business logic, but those downstream packages are not indexed at this module level.

## Notes for Developers

- **The root package is organizational only**: `com.fujitsu` itself contains no source files, classes, or methods. All actual code lives in downstream subpackages like `com.fujitsu.futurity`.
- **Scaffolding vs. production**: Many components in `futurity` are scaffolded — class structures are correct, but implementation bodies are deferred or no-op. For example, `X33JVRequestEncodingSjisFilter` currently forwards all requests unmodified, and `X33AppContextListener` has no lifecycle methods implemented. Always confirm whether the scaffold is the intended final structure or if implementation is expected.
- **Localization focus**: The X33 variant is a Japanese-market locale with Shift-JIS encoding support. If you're working on other market variants, check for related encoding filters or locale configurations in sibling web packages.
- **No data model at this level**: The `com.fujitsu` area contains no data model classes, DTOs, or entity types. It is purely a request-processing and lifecycle infrastructure layer. Business logic and data access reside in downstream packages.
- **Extensibility**: The filter's `init()` method is the natural place to read encoding parameters from `FilterConfig`. The `X33AppContextListener`, once implemented, would be the natural place to initialize locale-specific resources at startup (e.g., registering locale-aware `NumberFormat` or `DateFormat` instances).