# Root

## Overview

The `Root` area appears to be the top-level documentation umbrella for several small but related web integration namespaces. Based on the child pages, this part of the codebase is not a single feature module so much as a collection of entry points that connect the application to the servlet container and view layer.

Across the documented children, the system seems to split into three concerns:

- `com.fujitsu` provides the vendor/application namespace for the Futurity web application
- `eo.web` contains a configuration-driven screen/view assembly area
- `javax.faces` exposes the JSF servlet integration point used by deployment descriptors

Taken together, these modules appear to support a web application stack where container configuration, request handling, and screen rendering are wired together through descriptors and framework hooks rather than through a dense internal service layer.

## Sub-module Guide

### `com.fujitsu`

[`com.fujitsu`](.codewiki/com/fujitsu.md) is the namespace root for the Futurity application area. The child documentation shows that its meaningful behavior lives in `com.fujitsu.futurity`, especially the web integration layer.

Within that child area, the important pieces are:

- `X33AppContextListener` for application startup and shutdown
- `X33JVRequestEncodingSjisFilter` for request preprocessing

This relationship suggests a classic servlet-container split: one component manages lifecycle, while the other shapes inbound traffic before it reaches the application. The parent package itself looks like an organizing namespace, while the child package contains the operational wiring.

### `eo.web`

[`eo.web`](.codewiki/eo/web.md) appears to be the presentation-side module for a screen-oriented web application. Its documented child, `eo.web.webview`, centers on the `ACA001SF` screen flow.

The pieces work together as follows:

- `ACA001SFBean` carries the screen state
- `ACA001SFLogic` provides the lifecycle hook expected by the framework
- XML configuration binds bean, logic, and view together
- a JSP renders the final output

This module is more about assembly than computation. The Java types are intentionally thin, and the screen behavior seems to emerge from how the configuration maps those types to the view layer.

### `javax.faces`

[`javax.faces`](.codewiki/javax/faces.md) appears to be the JSF integration boundary. Its documented child, `javax.faces.webapp`, exposes `FacesServlet` as the named attachment point for the servlet container.

The integration model is descriptor-driven:

- `web.xml` references `FacesServlet`
- `web-full.xml` references `FacesServlet`
- the servlet container resolves and manages the servlet during application startup

Compared with `eo.web`, which is focused on screen composition, this module is focused on framework entry. It seems to provide the standard JSF hook that lets the rest of the web application participate in JSF-style request handling.

### How the modules relate

The child modules do not appear to call each other directly in the indexed evidence, but they fit into the same overall runtime story:

- `com.fujitsu` anchors the Futurity application namespace and container hooks
- `javax.faces` supplies the JSF servlet attachment point
- `eo.web` supplies a configuration-led screen/view pattern

In practice, these pieces likely cooperate at deployment time rather than through explicit package dependencies. The servlet container loads descriptors, descriptors point to integration classes, and those integration classes connect the app to request processing and rendering.

## Key Patterns and Architecture

### Configuration-first wiring

A dominant pattern across the child modules is configuration-first integration. Instead of constructing behavior through rich inter-module calls, the application appears to rely on XML deployment descriptors and framework configuration to assemble the runtime graph.

This shows up in multiple ways:

- servlet listeners and filters are registered through web descriptors
- JSF integration is attached through `FacesServlet`
- screen state and logic are bound to JSP views through XML

### Thin Java, strong container contracts

The documented Java types are small and specialized. That suggests the important contract is not local business logic, but the role each type plays in the container lifecycle:

- startup hooks
- request filters
- servlet entry points
- screen logic callbacks
- view beans

### Layered request flow

A plausible end-to-end flow emerges from the documentation:

1. The container starts the application and registers lifecycle hooks.
2. Requests enter through servlet- and filter-level entry points.
3. Framework configuration determines which screen or view flow is activated.
4. State is passed through a bean and rendered in a JSP or JSF-backed view.

### Mermaid diagram

```mermaid
flowchart TD
RootModule["Root"] --> ComFujitsu["com.fujitsu"]
RootModule["Root"] --> EoWeb["eo.web"]
RootModule["Root"] --> JavaxFaces["javax.faces"]
ComFujitsu --> Futurity["com.fujitsu.futurity"]
Futurity --> Listener["X33AppContextListener"]
Futurity --> Filter["X33JVRequestEncodingSjisFilter"]
EoWeb --> Webview["eo.web.webview"]
Webview --> ACA001SF["ACA001SF screen flow"]
ACA001SF --> Bean["ACA001SFBean"]
ACA001SF --> Logic["ACA001SFLogic"]
ACA001SF --> JSP["JSP view"]
JavaxFaces --> FacesServlet["FacesServlet"]
```

## Dependencies and Integration

### External integration points

The child pages indicate that integration happens primarily through deployment descriptors and web framework configuration:

- `web.xml` and `web-full.xml` are used to connect container-managed components
- JSP resources render the screen layer in `eo.web`
- `FacesServlet` serves as the JSF entry point in `javax.faces`

### Runtime relationship to the container

This area appears to depend heavily on the servlet container for lifecycle and request dispatch. The container is responsible for:

- instantiating the listener and servlet classes
- applying filter chains
- resolving XML-based configuration
- coordinating request routing to the correct screen or view

### Package-level evidence

The index reports no direct source files, classes, methods, or package dependencies at the `Root` level itself. That means the root module should be understood as a documentation and organizational umbrella rather than as an implementation package with its own code surface.

## Notes for Developers

- Treat `Root` as a system-level overview, not as a place where business behavior is implemented.
- Expect most changes in this area to be configuration-sensitive. Small naming changes can require updates in XML descriptors and view bindings.
- Keep lifecycle concerns separate from request handling and view rendering. The documentation suggests that separation is already part of the design.
- When debugging, start with descriptor wiring and container startup before assuming a Java code defect.
- `com.fujitsu`, `eo.web`, and `javax.faces` appear to represent different layers of the same web application stack, so changes in one layer may affect the others even when there is no direct Java dependency.
- This appears to be a thin but important integration layer, so the safest maintenance strategy is to preserve the existing container contracts unless there is a clear reason to rewire them.