# Com / Fujitsu / Futurity / Web ## Overview The `com.fujitsu.futurity.web` package serves as the web-tier boundary for the Fujitsu Futurity application. It represents the Java EE servlet-level infrastructure that sits between the HTTP transport layer and the application's business logic. Rather than containing business handlers directly, this package acts as a namespace for servlet lifecycle hooks, request filters, and other container-level entry points that govern how HTTP requests enter the application and how the application initializes and shuts down within the servlet container. At present, the only documented child module is `x33`, which provides stub infrastructure for request encoding and application lifecycle management. The broader web package is expected to grow as additional features are wired up — it currently functions as an extension point for servlet-level concerns such as character encoding, authentication, logging, and startup initialization. ## Sub-module Guide ### `x33` — Lifecycle and Encoding Scaffolding The `x33` sub-package is the sole documented entry point under the web package today. It provides two servlet-level hooks declared in `web.xml` and `web-full.xml`: - **`listener.X33AppContextListener`** — A placeholder for application startup and shutdown logic. The class is currently empty but is registered as a `` in deployment descriptors, following the Java EE convention for `ServletContextListener`-style hooks. When implemented, this component would be responsible for bootstrapping application state such as configuration loading, Spring context initialization, or resource pool setup. - **`filter.X33JVRequestEncodingSjisFilter`** — A servlet filter intended to handle Shift JIS (SJIS / cp932) character encoding for Japanese-language HTTP requests. Its name includes `JV` (Japan) and `Sjis` to signal its localization intent. Currently, the filter delegates every request to the next chain element without modification, making it a pass-through. This means Japanese input parameters will rely on the container's default encoding, which can produce garbled output (mojibake) if the server is not configured appropriately. #### How `x33` Components Relate to Each Other Both sub-components share a common parent package and deployment-time registration but have no direct code-level relationship. They operate at different points in the request lifecycle: the listener fires once at container startup, while the filter intercepts every subsequent HTTP request. Together they form a minimal scaffolding pattern — the listener is meant to prepare the application environment, and the filter is meant to normalize incoming request data. Neither component imports from or communicates with the other. ## Key Patterns and Architecture ### Deployment Descriptor-Driven Registration Both `x33` components are wired exclusively through deployment descriptors (`web.xml` and `web-full.xml`) rather than programmatic annotations like `@WebListener` or `@WebFilter`. This dual-registration across both the servlet-only profile and the full Java EE profile ensures the hooks activate regardless of which container profile the application runs on (e.g., Tomcat vs. a full Jakarta EE server). ### Scaffold / Stub Pattern The `x33` module follows a "declare the hook, leave the body empty" pattern. Both the listener and the filter are no-ops at the code level, suggesting this module was either planned for future implementation or its functionality was deferred. This is a common practice when setting up a new module or reserving extension points ahead of a sprint or release. ### Request Processing Flow The web package's architecture follows a standard Java EE servlet pipeline: the container invokes the listener once at startup, then routes each HTTP request through any registered filters before reaching the target servlet. The `x33` filter is positioned at the entry of this pipeline, making it the right place for request-level concerns like encoding normalization, though it currently performs no transformation. ```mermaid flowchart TD subgraph DEP["Deployment Descriptors"] web["web.xml / web-full.xml"] end subgraph STAGE1["Startup Phase"] regL["Registers X33AppContextListener"] end subgraph STAGE2["Request Phase"] regF["Registers X33JVRequestEncodingSjisFilter"] end DEP --> regL DEP --> regF regL --> emptyL["Empty stub - no-op"] regF --> emptyF["Delegates to chain - no-op"] ``` ```mermaid sequenceDiagram autonumber participant C as "Servlet Container" participant L as "X33AppContextListener" participant RQ as "X33JVRequestEncodingSjisFilter" participant FC as "FilterChain" participant S as "Target Servlet" C->>L: contextInitialized(event) activate L note right of L: No-op: empty class body deactivate L loop "For each HTTP request" C->>RQ: request arrives activate RQ RQ->>FC: chain.doFilter(req, res) RQ->>RQ: returns immediately deactivate RQ FC->>S: pass through unchanged S-->>C: response end ``` ## Dependencies and Integration ### External Dependencies This module and its child `x33` package have no Java-level imports beyond the standard `javax.servlet` API. There are no framework dependencies (Spring, Guice, CDI, etc.) declared or detected. The module is entirely self-contained within the Java EE servlet specification. ### Inbound Relationships | Artifact | Role | |---|---| | `web.xml` | Declares `X33AppContextListener` as a `` and `X33JVRequestEncodingSjisFilter` as a `` with associated `` entries. | | `web-full.xml` | Duplicate declarations for full-profile deployment environments. | | `com.fujitsu.futurity` (parent package) | The web package is a child of the top-level `com.fujitsu.futurity` namespace, which likely contains the business logic and service layer this web tier communicates with. | ### Outbound Relationships No classes from the `com.fujitsu.futurity.web` package are imported or referenced by other packages in the codebase. The module is a leaf in the dependency graph — it depends on nothing beyond the servlet API and is depended upon by nothing explicitly. This isolation means changes here have no downstream ripple effects across the application. ### Package Structure ``` com.fujitsu.futurity.web └─── x33 ├─── listener/ │ └─── X33AppContextListener.java — empty lifecycle stub └─── filter/ └─── X33JVRequestEncodingSjisFilter.java — no-op request filter ``` ## Notes for Developers - **Everything is currently a stub.** The listener class has no class body, and the filter's `doFilter`, `init`, and `destroy` methods are no-ops. Nothing at runtime depends on these components performing work. - **Japanese encoding is a known gap.** If the Futurity application serves Japanese-language users, the unhandled Shift JIS encoding is a real risk. To address this, `X33JVRequestEncodingSjisFilter.doFilter` should call `((HttpServletRequest) req).setCharacterEncoding("cp932")` before delegating to the chain. For robustness, wrap the request in a custom `HttpServletRequestWrapper` so that `getParameter` calls throughout the application respect the encoding. - **Listener implementation requires a design decision.** Before adding behavior to `X33AppContextListener`, determine whether it should implement `javax.servlet.ServletContextListener` (generic container lifecycle, receiving `contextInitialized`/`contextDestroyed`) or integrate with Spring (e.g., extend `ContextLoaderListener`). This choice dictates the API to implement and the `web.xml` configuration required. - **Thread-safety.** The filter is stateless, so thread-safety is not a concern today. Any future state added to either component should be handled with care, especially if the listener begins storing application-scoped resources. - **Low-risk area to modify.** Since no other package references classes from this module, changes here have no downstream impact. This module can be safely extended, refactored, or removed. - **Possible deprecation.** Given that both components are empty stubs with no cross-module references, it is worth verifying with the team whether the X33 module is still in scope. If not, the `x33` package and its `web.xml` entries can be cleaned up to reduce deployment confusion.