# Com / Fujitsu / Futurity / Web / X33

## Overview

The `com.fujitsu.futurity.web.x33` package is the web-layer entry point for the Fujitsu Futurity X33 subsystem. It provides the HTTP request processing infrastructure — lifecycle management and request filtering — for what appears to be a Japan-focused variant of the Futurity platform.

This module is thin today. It contains two packages: a **filter** that was intended to handle Shift-JIS character encoding for Japanese form data (currently a no-op stub), and a **listener** that is an empty skeleton class awaiting implementation. Both are wired into the Jakarta Servlet container lifecycle, but neither carries meaningful behavior yet.

The X33 package sits at the intersection of the web tier and the broader Futurity domain. When fully implemented, the listener would bootstrap application-scoped resources during startup, and the filter would ensure incoming requests with Japanese character encodings are decoded correctly before reaching downstream servlets.

## Sub-module Guide

### com.fujitsu.futurity.web.x33.filter

The filter package defines `X33JVRequestEncodingSjisFilter`, a Jakarta Servlet `Filter` registered in `web-full.xml`. Its name encodes its original intent: handle Shift-JIS (`Shift_JIS`) character encoding on incoming HTTP requests for the X33 Japan (JV) subsystem.

In practice, the `doFilter` method is a passthrough — it forwards every request unchanged without calling `setCharacterEncoding`. If Japanese Shift-JIS encoding support is required, this filter is the integration point, but the logic has not yet been added.

See the [filter package documentation](com/fujitsu/futurity/web/x33/filter.md) for the full class breakdown.

### com.fujitsu.futurity.web.x33.listener

The listener package currently contains `X33AppContextListener`, an empty stub class. Its naming suggests it was intended to implement either `ServletContextListener` (for servlet container lifecycle events) or a Spring `ApplicationListener` (for application-level events). The expected role is application bootstrap — loading configuration, initializing shared resources, or setting up application-scoped beans when the web app starts.

No methods or interfaces are implemented today. See the [listener package documentation](com/fujitsu/futurity/web/x33/listener.md) for details.

## How They Relate

Both packages serve complementary phases of the web-layer lifecycle:

- **Startup** (`listener`): The listener runs once when the application deploys, establishing shared state and wiring up resources.
- **Request time** (`filter`): The filter runs for every incoming HTTP request, inspecting and transforming the request before it reaches the target servlet.

The listener's bootstrap work (config loading, resource setup) feeds into what the filter — and the rest of the application — consumes at runtime.

```mermaid
flowchart TD
    subgraph WebLayer["com.fujitsu.futurity.web.x33"]
        direction TB
        Listener --> Init["bootstrap and init"]
        Init --> Filter
        Filter --> Chain["FilterChain.doFilter"]
        Chain --> Servlet["Target Servlet"]
    end
    Listener --> ListenerIF["ServletContextListener or ApplicationListener"]
    Filter --> FilterIF["javax.servlet.Filter"]
    ListenerIF --> Resources["Shared resources and config"]
    Filter --> Resources
```

## Key Patterns and Architecture

### Lifecycle-based separation of concerns

This module follows the common Java EE / Jakarta EE pattern of separating bootstrap logic from request-time processing:

- **The listener** owns `contextInitialized`-style setup code. When implemented, it will run once per application deployment.
- **The filter** owns per-request cross-cutting logic. It runs for every request, making it suitable for encoding, logging, authentication, or other transformations.

### Stub-first development pattern

Both sub-modules are currently stubs — the class declarations exist with correct package placement and naming, but no logic is implemented. This suggests one of two things: either the X33 subsystem is new and under active development, or these components were scaffolded in anticipation of future requirements.

### Filter chain delegation

The filter follows the standard Servlet Filter pattern: receive request, optionally transform, delegate to the next link in the chain via `FilterChain.doFilter()`. The current implementation skips the transformation step entirely.

### Package naming convention

The X33 identifier appears consistently:

| Pattern | Example |
|---|---|
| `X33JV` | `X33JVRequestEncodingSjisFilter` — Japan-focused variant |
| `X33` | `X33AppContextListener` — general X33 subsystem |
| `web.x33.*` | Leaf packages: `filter`, `listener` |

## Dependencies and Integration

### Internal dependencies

- **Parent module**: `com.fujitsu.futurity.web` — the broader X33 web layer.
- **Downstream**: `web-full.xml` deploys the filter into the servlet container.
- **Expected future**: Domain models, services, or Spring beans that the listener would initialize and the filter would interact with.

### External dependencies

- **`javax.servlet`**: Both the filter (`javax.servlet.Filter`) and the listener (likely `ServletContextListener` or Spring `ApplicationListener`) depend on the Jakarta / Java Servlet API.
- **Spring Framework (potential)**: If the listener implements `ApplicationListener`, it will introduce a Spring context dependency.

### Integration with the broader system

The X33 web module appears to be a Japan-targeted variant of the Futurity platform. The Shift-JIS encoding requirement (visible in the filter name) points to integration with Japanese legacy UIs or enterprise systems. The listener's bootstrap role suggests it may wire up encoding configuration, locale settings, or regional features consumed by other X33 components.

## Notes for Developers

- **Both sub-modules are unimplemented.** The filter is a no-op passthrough and the listener is an empty class. If you are tasked with adding X33 functionality, these are the entry points.
- **To enable Shift-JIS encoding**, update `X33JVRequestEncodingSjisFilter.doFilter()` to cast the request to `HttpServletRequest` and call `request.setCharacterEncoding("Shift_JIS")` before `chain.doFilter(req, res)`.
- **To wire up the listener**, add the appropriate interface (`ServletContextListener` or Spring `ApplicationListener`) and implement the lifecycle methods. Register it in `web-full.xml` or via Spring component scanning as appropriate.
- **Thread safety**: The filter holds no instance state and is thread-safe by design. If state is added, consider synchronization.
- **Shift-JIS vs UTF-8**: If the application is migrating away from Shift-JIS, consider whether the filter is still needed or should use UTF-8 instead.
- **No child modules exist** for either `filter` or `listener` — they are leaf packages.
- **No source files were indexed** for the parent `com.fujitsu.futurity.web.x33` package. The documentation below is synthesized entirely from the child wiki pages.