# Com / Fujitsu / Futurity / Web

## Overview

The `com.fujitsu.futurity.web` package sits at the servlet tier of the Fujitsu Futurity web application. It is responsible for the HTTP request-processing boundary of the system — where incoming browser requests enter the application and are prepared for dispatch into the core business logic layer.

The package currently contains one documented child subpackage, `x33`, which represents a Japanese-market locale variant of the application. The X33 module provides request infrastructure (filtering and lifecycle stubs) localized for Shift-JIS character encoding and Japanese locale conventions. At present, the X33 components are scaffolded rather than fully implemented — they establish the correct integration points (servlet filter, context listener) but defer the actual encoding and initialization logic.

This package is the entry point of the web-facing layer of the Futurity application. It does not contain business logic, data models, or service implementations. Its sole concern is preparing requests for downstream consumption by the application's internal tiers.

## Sub-module Guide

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

### x33 — Japanese-market locale variant

The `x33` subpackage provides locale-specific request infrastructure for the Japanese version of the Futurity application. It contains two sub-packages:

- **filter** (`X33JVRequestEncodingSjisFilter`) — The only active (registered) component in the web module. It is a servlet filter intended to normalize HTTP request character encoding to Shift JIS (SJIS) for Japanese-version requests. Currently a no-op passthrough, it is wired in the deployment descriptor (`web-full.xml`) so the servlet container invokes it on matching requests.
- **listener** (`X33AppContextListener`) — A dormant placeholder class following the `ServletContextListener` naming convention. It is scaffolded but contains no methods or interfaces. When implemented, it would handle application startup and shutdown tasks (e.g., initializing locale-aware formatters, connection pools, or encoding configuration) to complement the filter's per-request encoding work.

**Relationships between sub-modules:**

Both X33 sub-components operate at the servlet infrastructure boundary. The listener (once implemented) initializes shared resources at application startup, while the filter processes each incoming request. Together they form the X33 request pipeline entry point, all focused on a single concern: ensuring the Japanese locale environment is correctly set up before request data reaches the application's core logic.

The filter is the only registered and container-invoked component; the listener remains a stub waiting for implementation. Their shared focus on character encoding (SJIS) and locale setup suggests they are designed to work in tandem — one at startup time, one per request.

```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 enter the Futurity application through the servlet container, which invokes the X33 filter before dispatching to the target servlet. This filter-chain pattern is the standard Java EE approach for pre-processing requests:

```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 design allows the X33 filter to intercept and transform requests (such as normalizing character encoding) before they reach business logic — a common pattern for internationalized applications.

### Pass-through and Scaffolding Patterns

The X33 module exhibits 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.

### Architecture Position

The web package sits between the servlet container (the HTTP boundary) and the application's internal tiers:

```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.

## 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 and request/response types. |

### 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, but those relationships are defined outside this package.

## Notes for Developers

- **Intended vs. current behavior:** The `X33JVRequestEncodingSjisFilter` was designed to handle Shift-JIS encoding for Japanese requests but currently forwards all requests unmodified. To implement the 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 listener, 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.