# Com / Fujitsu / Futurity / Web

## Overview

The `com.fujitsu.futurity.web` package is the web-tier layer of the Fujitsu Futurity application. It provides the servlet-based presentation boundary — the entry point where HTTP requests enter the application and where web-specific lifecycle, encoding, and request-processing concerns are addressed before requests reach business logic or data access layers.

Currently, this package functions primarily as an infrastructure scaffold. It does not contain controllers, views, or business logic. Instead, it provides the structural hooks — servlet filters, context listeners, and deployment descriptor wiring — through which the Futurity application intercepts, transforms, and manages the lifecycle of web traffic. The package is organized into sub-modules, each responsible for a distinct aspect of web-layer concerns.

At present, most of the sub-module implementations are stubs or pass-through components. This suggests one of two things: either the X33 application (the primary web-facing module within this package) is in early-stage scaffolding with its infrastructure hooks created ahead of business logic, or an older version of the application has been decommissioned and the web-layer skeleton remains as a structural foundation for future development.

## Sub-module Guide

### X33 — `com.fujitsu.futurity.web.x33`

The X33 sub-module is the sole documented child of the web package. It represents a distinct application or module within the Futurity suite, likely a Japan-focused variant given naming cues such as `Sjis` (Shift JIS encoding) and `JV` (Japan). X33 is responsible for:

- **Request encoding management** — ensuring incoming HTTP requests with Japanese content are parsed with the correct character set.
- **Application lifecycle management** — providing startup and shutdown hooks for application-scoped resources.

X33 decomposes further into two sub-components:

| Sub-component | Class | Purpose |
|---|---|---|
| Filter | `X33JVRequestEncodingSjisFilter` | Intercept HTTP requests and set character encoding to MS932 (Shift JIS) for Japanese content. |
| Listener | `X33AppContextListener` | Implement `ServletContextListener` for application-wide startup and shutdown logic. |

Both components are registered via deployment descriptors (`web.xml`, `web-full.xml`) but have no-op or empty implementations today. The filter passes every request through unmodified, and the listener's class body is structurally empty. Together, they form the complete set of servlet-tier hooks — lifecycle-level (listener) and request-level (filter) — but neither carries any signal yet.

#### How the sub-modules relate

Within the X33 sub-module, the filter and listener follow the standard Java EE servlet architecture pattern: the **listener** operates at the application boundary (fired once when the web container starts or stops), while the **filter** operates at the per-request boundary (fired for every HTTP request). In a fully implemented X33 application, the listener would bootstrap shared state (data sources, cached lookups) at deploy time, and the filter would transform each request (e.g., setting character encoding) before it reaches controllers. As stubs, they represent a structural skeleton — the scaffolding is in place, the plumbing is wired through `web.xml`, but the pipes are not yet carrying any signal.

## Key Patterns and Architecture

```mermaid
flowchart LR
  A["Futurity Application"] --> B["com.fujitsu.futurity.web
Web Tier"]
  B --> C["X33 Sub-module"]
  C --> D["Filter:
X33JVRequestEncodingSjisFilter"]
  C --> E["Listener:
X33AppContextListener"]
  D --> F["Pass-through:
no-op today"]
  E --> G["Lifecycle hooks:
stub — no-op today"]
```

### Architectural observations

- **Lifecycle-Request separation:** The filter and listener cleanly separate concerns — one handles the application lifecycle, the other handles per-request transformation. This is the standard servlet architecture pattern in Java EE.
- **Stub scaffolding:** Both components follow an identical skeleton pattern: a class implementing a servlet API interface with empty or no-op method bodies. This pattern typically indicates either early-stage scaffolding where infrastructure hooks are created before business logic is written, or a decommissioned component whose logic was migrated elsewhere.
- **Deployment descriptor-driven:** Neither component is discovered via annotation scanning or programmatic registration. They are explicitly declared in `web.xml` and `web-full.xml`, meaning the X33 application uses XML-based deployment configuration rather than Servlet 3.0+ annotation-based discovery (or supports both).
- **No cross-module integration yet:** No imports flow into or out of the X33 package, and no other modules reference classes from `com.fujitsu.futurity.web.x33`. This isolation suggests the X33 application may currently operate as a standalone web module within the broader Futurity ecosystem, with integration points not yet wired.

## Dependencies and Integration

### Internal dependencies

The X33 web package has **no Java-level dependencies** on other internal modules. Neither the filter nor the listener imports any classes from within the Futurity application. This is consistent with their stub status — there is no executable logic to require imports.

### External dependencies

Both components depend only on the standard Java Servlet API:

| Dependency | Used by | Purpose |
|---|---|---|
| `javax.servlet.Filter` | `X33JVRequestEncodingSjisFilter` | Servlet filter interface |
| `javax.servlet.ServletRequest` / `ServletResponse` | `X33JVRequestEncodingSjisFilter` | Request/response objects in `doFilter()` |
| `javax.servlet.FilterChain` | `X33JVRequestEncodingSjisFilter` | Passes requests through the filter chain |
| `javax.servlet.FilterConfig` | `X33JVRequestEncodingSjisFilter` | Init parameters and context reference |
| `javax.servlet.ServletContextListener` / `ServletContextEvent` | `X33AppContextListener` | Application lifecycle hooks |

### Deployment configuration

| File | Component registered |
|---|---|
| `web.xml` | Both `X33JVRequestEncodingSjisFilter` and `X33AppContextListener` |
| `web-full.xml` | Both `X33JVRequestEncodingSjisFilter` and `X33AppContextListener` |

The fact that both profiles reference these components means any implementation work should be reflected in both deployment descriptors to avoid environment-specific behavior.

## Notes for Developers

- **Everything is a stub.** Neither the filter nor the listener has executable logic. Adding implementation is safe — there is no existing behavior to break.
- **Character encoding is a priority area.** If the X33 application handles Japanese content, implementing the `X33JVRequestEncodingSjisFilter` is likely one of the first practical tasks. The recommended approach is to check `req.getCharacterEncoding() == null` before setting the encoding, to avoid overriding an explicit client-specified `Content-Type` header.
- **Servlet API version matters.** The code comments reference `javax.servlet` (Java EE / Servlet 3.x), but the project may have migrated to `jakarta.servlet` (Jakarta EE / Servlet 5.x+). Confirm the build configuration before implementing any interface methods.
- **Coordinate across profiles.** Any changes to `web.xml` or `web-full.xml` should be kept in sync. Divergence between these profiles is a common source of environment-specific bugs.
- **This appears to be a structural foundation.** The presence of properly named and deployed stubs suggests this package is intended to grow into a fully functional web tier. Developers working on X33 should treat these classes as extension points rather than dead code.
- **Indexing caveat:** Static analysis of this module reports zero indexed classes and methods, because the stub classes are minimal (interfaces are implemented but method bodies are empty). When implementation is added, the index will need to be refreshed to capture the new symbols.