Glossary

Dirty object: An object held by an application, whose state has changed since the it was first loaded from the database. (In other words, the application's view of the object's state is different than the original view taken from the database.)

Domain: The real-world environment modeled by a business application.

Domain object: Objects representing things in the business domain, such as people, products, bank accounts, production lines, vehicles, etc.

HTML: HyperText Markup Language. A markup language used to control the presentation of content in a Web page. HTML is an SGML (Standard Generalized Markup Language) DTD (Document Type Definition).

HTTP: HyperText Transfer Protocol. A protocol used to exchange information between a Web browser and a Web server.

JavaScript: An interpreted scripting language which can be embedded in HTML pages to provide various kinds of behavior. It has a Java-like syntax, hence the name.

JSP: Java Server Page. A specialized form of HTML page that supports tags to call out to JSP beans to generate dynamic page content. JSPs effectively separate HTML from the business logic needed to generate dynamic content.

JSP bean: A specialized Java bean invoked by a JSP page.

Metadata: Information describing how a particular field in a class is mapped into a table and row in a database.

Object graph: A set of connected objects. An object graph starts with a selected object and contains objects to which that object holds direct or indirect references.

OODB: Object-oriented database. A database that persists objects in their native form, avoiding the need for object-to-relational mapping.

RDBMS: Relational database management system. A database that stores its information in tables of rows and columns.

Semantic validation: Validation that an input value makes sense in the context of the application. For example, the presentation layer of a system may check that input to a field of type string (syntactic validation). The domain layer does semantic validation to confirm that the string is a valid account number or product code.

Serialization: Conversion of an object to a serial stream of data for distribution over a network.

Servlet: A Java program that implements the Java servlet interface. Servlets are run in servlet engines to produce pages with dynamic content. In contrast to JSPs, servlets are raw Java and generate their HTML output through manipulation and concatenation of strings.

Transitive closure: The complete set of all the objects to which an object holds references, either directly or indirectly. (In other words, a Person object may hold reference to several Child objects, each of which hold references to School objects, which hold Address objects, etc. The transitive closure of the Person object includes all of these.)

Use case: A task that is part of the business process, for example, renewing insurance policies in an insurance application.

Workstep: Work that is done within the context of a single database transaction. In the long transaction model, workstep and use case tend to coincide. In the short transaction model, the use case must be broken into two or more worksteps.