# ACA001SFBean ```java package eo.web.webview.ACA001SF; public class ACA001SFBean { private String value; public String getValue() { return value; } } ``` **Source:** `full-fixture-codebase/src/java/eo/web/webview/ACA001SF/ACA001SFBean.java` ## Purpose `ACA001SFBean` is a minimal JavaBean that acts as a data carrier within the Futurity web framework's screen-definition model. It provides a single `String`-typed property (`value`) accessible through the standard JavaBeans getter convention (`getValue()`). In the context of the application, it serves as a **service-form bean** — a lightweight data object that the Futurity view layer uses to exchange values between screen definitions (XML configs), logic classes, and JSP presentation pages. ## Design This class follows the **JavaBeans data object** pattern (often called a POJO — Plain Old Java Object). It has no superclass, implements no interfaces, and contains only a single private field with a public getter. There is no setter defined, meaning the `value` field is write-once (or write-only from the same package) once initialized. Architecturally, `ACA001SFBean` sits at the intersection of three Futurity layers: 1. **Screen Definition** — An XML screen config references the bean via the `` element, binding the Futurity framework to use it as the form data carrier. 2. **Logic Layer** — The companion `ACA001SFLogic` class is declared as the business logic handler for the same screen. The logic class would interact with the bean to read or populate the `value` field. 3. **Presentation Layer** — JSP pages instantiate the bean via `` with a request scope, then access its properties for rendering. ``` ┌──────────────────────┐ ┌──────────────────────┐ │ Screen Definition │ ───────────────────── │ ACA001SFBean │ │ (WEBGAMEN_*.xml) │ │ (data carrier) │ └──────────────────────┘ └──────────┬───────────┘ │ │ getValue() ▼ ┌──────────────────────┐ ┌─────────────────────────────┐ │ JSP Presentation │ ──▶ │ web/struts-style form │ │ (*.jsp) │ │ data extraction │ └──────────────────────┘ └─────────────────────────────┘ ``` ### Relationship Diagram ```mermaid flowchart TD screen["Screen: FULL_ACA001 (SCREEN id)"] -->|declares| xxml["WEBGAMEN_FULL_ACA001.xml (Screen Definition)"] xxml -->|binds SERVICEFORM to| bean["ACA001SFBean (eo.web.webview.ACA001SF)"] xxml -->|declares BL class| logic["ACA001SFLogic"] jsp["FULL_ACA001010PJP.jsp (View Page)"] -->|jsp:useBean scope=request| bean bean -->|getValue returns| data["String value (plain field)"] ``` ## Key Methods ### `getValue() → String` - **Signature:** `public String getValue()` - **Line:** 4 - **Return:** The current value of the private `String value` field, or `null` if never set. - **Side effects:** None — this is a pure accessor with no computation, validation, or state mutation. This is the sole public method of the class. By JavaBeans naming convention, `getValue()` exposes the private `value` field as a readable property. In the JSP context, this means the property can be accessed via Expression Language (`${myBean.value}`) or JSP bean property syntax (``). Notably, **there is no corresponding `setValue(String)` method**, which means: - From JSPs, the field can be read but not directly written via `` (unless a setter exists elsewhere or the value is set from the logic layer). - The `value` field can only be set from within the same package (package-private access to the default field) or by a subclass. - In practice, this suggests the bean is populated by the Futurity framework's screen-definition binding mechanism at runtime, rather than by direct method calls. ## Relationships ### Inbound Dependencies (Who uses this class) | Dependent | Type | How it references ACA001SFBean | |-----------|------|-------------------------------| | `WEBGAMEN_FULL_ACA001.xml` | XML screen definition | `` — registers it as the form data carrier for the FULL_ACA001 screen | | `FULL_ACA001010PJP.jsp` | JSP view page | `` — instantiates it with request scope for the page | | `WEBGAMEN_ACA001010PJP.xml` | XML screen definition | References the bean (exact binding context) | | `x33S_ACA001.xml` | XML Japanese element definition | References the bean (likely for Japanese-language screen form mapping) | | `faces-config.xml` | JSF configuration | References the bean (may declare it as a managed bean for the JSF lifecycle) | ### Outbound Dependencies No outbound references were found. `ACA001SFBean` depends only on `java.lang.String` (implicitly, via its field type), which is part of the Java runtime. This makes it a **leaf data object** — a pure value holder with no dependencies of its own. ### Class Diagram ```mermaid classDiagram class ACA001SFBean { -String value +getValue() String } note for ACA001SFBean "No setter defined. No dependencies beyond java.lang.String." WEBGAMEN_FULL_ACA001.xml --> ACA001SFBean : binds as SERVICEFORM FULL_ACA001010PJP.jsp --> ACA001SFBean : usesBean request scope ``` ## Usage Example Within the Futurity framework, a typical request cycle involving `ACA001SFBean` flows as follows: 1. **Screen Definition (XML):** The administrator or developer defines a screen named `FULL_ACA001` in `WEBGAMEN_FULL_ACA001.xml`, binding `ACA001SFBean` as the service form. 2. **Logic Execution:** When the screen is invoked, the Futurity framework instantiates the declared logic class (`ACA001SFLogic`) and the service form bean. The logic class is responsible for populating the bean's `value` field. 3. **JSP Rendering:** The JSP page (`FULL_ACA001010PJP.jsp`) declares the bean: ```jsp ``` It then accesses the value, e.g.: ```jsp

``` or via Expression Language: ```jsp

${logic.value}

``` The bean's role is to carry data from the logic layer back to the presentation layer without imposing any business logic of its own. ## Notes for Developers - **No setter:** The absence of `setValue()` means the bean is effectively read-only from the outside. If you need to set the value, check whether the Futurity framework's `` binding mechanism sets it automatically, or add a setter method. - **Request-scoped:** In `FULL_ACA001010PJP.jsp`, the bean is instantiated with `scope="request"`. This is appropriate for a per-request data carrier and avoids session-level memory leaks. - **Thread safety:** As a request-scoped bean with a single mutable `String` field, it is not inherently thread-safe. However, since each request gets its own instance (via ``), concurrent requests do not share state. If the bean were ever used with `scope="session"` or `scope="application"`, concurrent access to `value` would need synchronization. - **Immutable by convention:** Although the field is not declared `final`, the lack of a setter means that once a value is assigned (typically by the Futurity framework during screen execution), it cannot be changed. Treat it as effectively immutable for callers. - **Minimal design:** This class is intentionally trivial. Its importance (6 inbound connections) comes not from its own complexity but from its role as a shared data nexus between the screen definition, logic layer, and JSP presentation — a common pattern in Java EE MVC architectures where plain beans shuttle data across the MVC triad. - **Futurity framework convention:** The `eo.web.webview` package naming and the use of `` / `` XML elements suggest this is part of the **Futurity** enterprise web framework (developed by Fujitsu), which uses XML-driven screen definitions to wire together JavaBeans, logic classes, and JSPs without explicit controller code.