# Com / Fujitsu / Futurity

## Overview

The `com.fujitsu.futurity` package is the root namespace for the Fujitsu Futurity web application — a Java EE application that delivers a browser-based user interface backed by servlet-tier request handling and internal business logic. The package hierarchy is organized by architectural concern, with the `web` subpackage sitting at the HTTP boundary as the entry point for all browser requests.

Futurity appears to be a multi-market application with locale-specific variants. The best-documented variant is **X33** (Japanese Version), which provides Shift-JIS character encoding support through servlet filters and lifecycle infrastructure. The application follows a layered architecture where the web tier intercepts and normalizes requests before dispatching them into the core business logic and service layers.

The application does not expose data model classes, DTOs, or entity types at the module level — its primary concern is request-processing infrastructure and locale-aware configuration, with actual business logic and data access residing in downstream packages not indexed at this level.

## Sub-module Guide

The `com.fujitsu.futurity` package has one documented child subpackage:

### web — the HTTP request-processing boundary

The `web` package occupies the servlet tier of the Futurity application. It receives incoming HTTP requests from the browser, normalizes request-level concerns (such as character encoding), and dispatches prepared requests into the application's internal tiers. It contains no business logic, data models, or service implementations.

#### x33 — Japanese-market locale variant

The `web/x33` subpackage provides locale-specific infrastructure for the Japanese version of Futurity. It establishes two integration points:

- **`filter`** — `X33JVRequestEncodingSjisFilter` is a registered servlet filter (declared in `web-full.xml`) that intercepts matching HTTP requests. Its intended purpose is to set the request character encoding to Shift JIS before the request reaches the target servlet. As currently implemented, it is a no-op passthrough that forwards requests unmodified.
- **`listener`** — `X33AppContextListener` is a scaffolded class following the `ServletContextListener` naming convention. It is not yet implemented or registered with the servlet container. When completed, it would handle startup and shutdown tasks such as initializing locale-aware formatters or encoding configuration.

**How x33's components work together:** The listener and filter operate at different points in the request lifecycle. The listener initializes shared, application-wide resources at startup. The filter processes each incoming request individually. Both serve the same overarching goal: ensuring the Japanese locale environment is correctly configured before request data reaches the application's core logic. The filter is the only component actively invoked by the servlet container today.

#### Package structure

```mermaid
flowchart TD
    X33["x33 subpackage<br/>Japanese locale variant"]
    X33 --> Filter["filter<br/>X33JVRequestEncodingSjisFilter<br/>Servlet Filter (registered)"]
    X33 --> Listener["listener<br/>X33AppContextListener<br/>Lifecycle stub"]
```

## Key Patterns and Architecture

### Request Pipeline Architecture

Incoming requests from browsers flow through the following path:

```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
```

This is the standard Java EE filter-chain pattern. The X33 filter sits at the boundary, capable of intercepting and transforming requests (particularly character encoding) before they reach the application's business logic. This is a common pattern for internationalized applications that must handle multiple character encodings.

### Architectural Layering

The Futurity application follows a layered architecture, with the web tier as the outermost layer:

```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 that can enforce encoding or locale constraints before data enters the application's core processing pipeline. Each subsequent layer handles progressively higher-abstraction concerns.

### Scaffolding Pattern

The X33 sub-modules exhibit a scaffolding pattern: class structures are defined to establish correct integration points (implementing `javax.servlet.Filter`, naming a `ServletContextListener`), but the implementation body is deferred. The filter currently passes requests through unmodified, and the listener has no lifecycle methods. This approach is common in localization work where the framework is set up before locale-specific logic is fully specified.

## Dependencies and Integration

### Inbound dependencies

| Dependency | Role |
|---|---|
| `web-full.xml` | Deployment descriptor that registers `X33JVRequestEncodingSjisFilter` with the servlet container, defining its URL patterns and init parameters. |

### Outbound dependencies

| Dependency | Role |
|---|---|
| `javax.servlet.*` | Standard Java EE Servlet API — the filter interface (`javax.servlet.Filter`), request/response types (`HttpServletRequest`, `HttpServletResponse`), and the listener interface (`ServletContextListener`). |

### Cross-module context

The `com.fujitsu.futurity.web` package is a child of the root `com.fujitsu.futurity` application package hierarchy. The X33 subpackage is a locale-specific variant; sibling packages or parallel implementations for other locales (e.g., an English variant) may exist, 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 — those relationships are defined outside this package.

## Notes for Developers

- **Intended vs. current behavior:** `X33JVRequestEncodingSjisFilter` was designed to handle Shift-JIS encoding for Japanese requests but currently forwards all requests unmodified. To implement encoding normalization, add `setCharacterEncoding("SJIS")` (cast the request to `HttpServletRequest`) or wrap it with a custom `HttpServletRequestWrapper` before delegating to the chain.

- **Extension points:** The filter's `init()` method is the natural place to read encoding parameters from `FilterConfig`, making the encoding configurable via `web.xml`. The `X33AppContextListener`, once implemented, would be the natural place to initialize locale-specific resources at startup (e.g., registering `java.text.NumberFormat` or `DateFormat` instances for the Japanese locale, or setting system properties for character encoding).

- **Thread safety:** As a servlet filter with no instance state, `X33JVRequestEncodingSjisFilter` is inherently thread-safe. No synchronization concerns exist.

- **Activating the listener:** `X33AppContextListener` is not currently registered with the servlet container. To activate it, implement `javax.servlet.ServletContextListener`, add `contextInitialized()` and `contextDestroyed()` methods, and wire it in `web.xml` via `<listener>` elements or the `@WebListener` annotation.

- **X33 as a locale variant:** The "X33" naming, combined with "JV" (Japanese Version) in the filter name and Shift-JIS references, indicates this is a locale-specific variant. Developers working in X33 should check for related encoding filters or locale configurations in sibling web packages for other markets.

- **No data model:** This module contains no data model classes, DTOs, or entity types. It is purely a request-processing and lifecycle infrastructure layer.

- **No active behavior yet:** Both sub-modules contribute zero executable behavior at present. Production impact depends on whether they are referenced from configuration files and whether implementation work is completed. Any developer adding functionality should first confirm whether the scaffold is the intended final structure or if implementation is expected.