# Com / Fujitsu / Futurity / Web

## Overview

The `com.fujitsu.futurity.web` package forms the **web tier** of the Futurity application platform. This is the entry boundary where the Java servlet container routes HTTP traffic into the application, providing lifecycle hooks (via context listeners) and request-processing interceptors (via filters) that sit between incoming requests and the target servlets or controllers.

The Futurity platform appears to follow a **regional-variant** architecture: the x33 subpackage is scoped for the Japanese market (indicated by the `JV` suffix on its filter class), suggesting sibling packages exist for other regions such as `X33US` (US) and `X33EU` (Europe). This structure lets each market variant define its own character encoding, localization, and startup behaviour while sharing the broader Futurity application logic.

At the current state of the index, the module is largely a **skeleton**. The `x33` subpackage registers both a listener and a filter through deployment descriptors, but neither component contains active runtime logic. This pattern typically indicates either a fresh module awaiting feature development, or logic that was migrated to a higher-level layer (such as global servlet container configuration).

## Sub-module Guide

The web tier currently documents one child module:

### x33 — Japanese-market variant

The `com.fujitsu.futurity.web.x33` package and its two sub-packages form the complete web-tier initialisation and request-processing pipeline for the Japanese market deployment of Futurity.

**`x33.filter` — Request encoding filter**

`X33JVRequestEncodingSjisFilter` is a Servlet `Filter` placed in the request pipeline. Its name indicates an original intent to set incoming HTTP request character encoding to **Shift JIS** (`MS932`), a standard encoding for legacy Japanese enterprise applications. At present it is a **pass-through no-op**: `doFilter()` delegates immediately to `chain.doFilter(req, res)` without modifying the request or response.

**`x33.listener` — Application context listener**

`X33AppContextListener` is registered as a servlet context listener in `web.xml`. It marks the intended entry point for x33-specific application bootstrapping during container startup and shutdown. Currently it is a **stub** with no methods or imports. When implemented, it would override `contextInitialized()` to load configuration, initialise caches, or set up database connections, and `contextDestroyed()` for cleanup.

**How they work together**

These two components follow the standard Java EE servlet lifecycle:

1. **Startup**: The container loads the application, fires `X33AppContextListener.contextInitialized()`, and any x33-specific resources are bootstrapped here.
2. **Request handling**: Each incoming HTTP request enters the servlet container's filter chain, where `X33JVRequestEncodingSjisFilter.doFilter()` would intercept the request before forwarding it to the target servlet.
3. **Shutdown**: `X33AppContextListener.contextDestroyed()` runs when the application is undeployed.

Together they form the **initialisation and request-processing layer** for the x33 variant. In a fully implemented state, the listener would set up shared state (e.g., a character encoding filter configured with `MS932`), and the filter would enforce that encoding on each request before it reaches the application.

## Key Patterns and Architecture

### Servlet lifecycle scaffolding

Both the filter and the listener implement standard Java EE interfaces — `javax.servlet.Filter` and `javax.servlet.ServletContextListener` — but neither contains application-specific logic. The module is designed as a **hook framework**, with the actual work deferred to configuration or sibling packages.

### Deployment descriptor wiring

All components are wired exclusively through `web.xml` (and its full variant, `web-full.xml`), with no Spring annotations or Java-based configuration visible. This is consistent with a traditional Java EE servlet container approach. The presence of `web-full.xml` suggests environment-specific override profiles (e.g., a full deployment with additional features or different filter mappings).

### No-op pattern across the module

Both the filter and the listener follow an identical architectural signal: they exist in the codebase and deployment descriptors but do nothing at runtime. This indicates one or more of:

1. **Future extension** — the skeleton is in place and implementation is deferred.
2. **Migration aftermath** — logic existed previously but was moved elsewhere (e.g., to a global encoding filter or container-level configuration in `server.xml`).
3. **Variant scaffolding** — x33 shares infrastructure with other regional variants, with regional-specific logic implemented in sibling packages (e.g., `X33US`, `X33EU`).

### Architecture diagram

```mermaid
flowchart TD
    subgraph FuturityWeb["com.fujitsu.futurity.web - Web Tier"]
        subgraph x33Mod["x33 Module - Japanese Market Variant"]
            Listener["X33AppContextListener
(lifecycle entry point)"]
            Filter["X33JVRequestEncodingSjisFilter
(request encoding)"]
        end
    end

    subgraph Deployment["Deployment Layer"]
        WebXML["web.xml / web-full.xml"]
        Container["Servlet Container"]
    end

    subgraph Runtime["Runtime Flow"]
        Request["Incoming HTTP Request"]
        Pipeline["Filter Pipeline"]
        App["Application Servlets"]
    end

    WebXML -->|"registers"| Listener
    WebXML -->|"registers and maps"| Filter
    Request -->|"enters"| Pipeline
    Pipeline -->|"passes to"| App
    Filter -.->|"intercepts"| Pipeline
    Listener -.->|"bootstraps"| Container
```

### Character encoding convention

The filter's name (`X33JVRequestEncodingSjisFilter`) strongly suggests that Shift JIS (`MS932`) is the intended encoding for incoming requests on the Japanese variant. When the filter is implemented, it would call `req.setCharacterEncoding("MS932")` before delegating to the filter chain. Alternatively, encoding could be configured at the servlet container level via the `URIEncoding` attribute in `server.xml`.

## Dependencies and Integration

### External dependencies

- **`javax.servlet`** — The standard Java Servlet API provides the `Filter`, `FilterConfig`, `FilterChain`, `ServletRequest`, `ServletResponse`, and `ServletContextListener` interfaces used by both child sub-modules.

### Registration

- **`web.xml`** — Both the listener and the filter are registered in the primary web descriptor.
- **`web-full.xml`** — The filter also appears in the full deployment variant, suggesting environment-specific overrides or a separate deployment profile.

### Integration with the broader platform

No cross-module relationships were detected in the index (consistent with the stub/no-op state). Any integration with the broader Futurity platform would occur through:

- **Shared servlet container configuration** — e.g., `server.xml` for encoding defaults or connection pool settings.
- **Deployment descriptor references** — `web.xml` may reference sibling packages for the complete variant chain.
- **`ServletContext` attributes** — Once implemented, the listener would set shared state via `ServletContext.setAttribute()`, making x33-specific resources available to all servlets and filters.
- **Sibling regional variants** — Adjacent packages (e.g., `X33US`, `X33EU`) likely mirror this structure with region-specific encoding and lifecycle logic.

## Notes for Developers

- **Both child modules are skeletal.** Neither the filter nor the listener contains active logic. Before making changes, verify whether encoding or initialisation logic is handled elsewhere (servlet container config, global filters, or sibling packages).
- **The filter is safe to remove or deprecate.** Since `X33JVRequestEncodingSjisFilter.doFilter()` simply passes requests through without modification, removing it from `web.xml` will have no runtime impact unless deployment descriptor ordering depends on its presence.
- **If encoding needs to be re-added**, the standard approach is to call `req.setCharacterEncoding("MS932")` (Shift JIS) before `chain.doFilter(req, res)` in the filter's `doFilter()` method. Alternatively, configure the servlet container's `URIEncoding` attribute.
- **The listener should implement `ServletContextListener`** when lifecycle logic is added. The `contextInitialized()` method is the natural place to bootstrap x33-specific resources.
- **Naming convention.** The `X33` prefix scopes these components to the x33 module variant. Adjacent packages likely serve other regional variants with their own filter and listener classes.
- **No source files are currently indexed** for the parent `web` package itself. The documentation above is synthesised from the child module pages and the broader platform architecture context.