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Interpreting Unified Modeling Language Diagrams

This manual uses the Unified Modeling Language (UML) to present use case diagrams as a way of explaining technology. A brief explanation of use case diagrams and UML notation follows.

See Also: Oracle9i Application Developer's Guide - Large Objects (LOBs)

Use Case Diagrams

Graphic Element	Description
Text description of the illustration qapumla.gif	In a use case diagram, each primary use case is instigated by an actor (stickman), which can be a human user, an application, or a subprogram. The actor is connected to the primary use case, which is depicted as an oval (bubble) enclosing the use case action. The totality of primary use cases is described in a use case model diagram.
Text description of the illustration uml002.gif	Primary use cases may require other operations to complete them. In this diagram fragment specify queue name is one of the suboperations, or secondary use cases, needed to complete ENQUEUE a message The downward lines from the primary use case lead to the other required operations (not shown).
Text description of the illustration uml003.gif	A secondary use case with a drop shadow expands into its own use case diagram, thus making it easier to: Understand the logic of the operation Continue a complex operation across multiple pages In this example specify message properties, specify options add payload are all expanded in separate use case diagrams. In the online versions of these diagrams, these are clickable areas that link to the related operation.
Text description of the illustration uml004.gif	This diagram fragment shows the expanded use case diagram. While the standard diagram has the actor as the initiator, here the use case itself is the point of departure for the suboperation. In this example, the expanded view of add payload represents a constituent operation of ENQUEUE a message
Text description of the illustration uml005.gif	The a, b, c convention shows that there are three ways to create a table containing LOBs.
Text description of the illustration uml006.gif	This fragment shows one of the uses of a note box, here presenting one of the three ways to create a table containing LOBs.

Graphic Element Text description of the illustration uml007.gif

Description This drawing shows other uses of note boxes: Note boxes can present an alternative name. In this case, the action SELECT propagation schedules in the user schema is represented by the view USER_QUEUE_SCHEDULES. Note boxes can qualify the use case action. In this case, the list attribute names action is qualified by the note that you must list at least one attribute if you do not list all the attributes of the propagation schedule.

Graphic Element	Description
Text description of the illustration uml008.gif	The dotted arrow in the use case diagram indicates dependency. In this example free a temporary LOB requires that you first create a temporary LOB Put another way: you should not execute the free operation on a LOB that is not temporary. The target of the arrow shows the operation that must be performed first.
Text description of the illustration uml009.gif	Use cases and their suboperations can be linked in complex relationships. In this example of a callback, you must first REGISTER for notification in order to later receive a notification

Graphic Element Text description of the illustration uml007.gif

Description In this case the branching paths of an OR condition are shown. In invoking the view, you can choose to list all the attributes or view one or more attributes. The grayed arrow indicates that you can stipulate which attributes you want to view.

Graphic Element Text description of the illustration uml011.gif

Description The black dashed line and arrow indicate that the targeted operation is required. The gray dashed line and arrow indicate that the targeted operation is optional. In this example, executing write append on a LOB requires that you first SELECT a LOB You may optionally choose to OPEN a LOB or get chunk size Note that if you do OPEN a LOB, you must CLOSE it.

State Diagrams

Graphic Element Text description of the illustration qapuml12.gif

Description The previous notes have discussed use case diagrams. Here we introduce the basic application of a state diagram, which we use to present the attributes of view. Attributes of a view have only two states--visible or invisible. We are not interested in showing the permutations of state, but in showing what you can make visible in invoking a view. Accordingly, we have extended the UML to join a partial state diagram onto a use case diagram to show the totality of attributes, and thereby all the substates of the view that you can see. We have demarcated the use case from the view state by coloring the background gray. In this example, the view allows you to query queue subscribers. You can stipulate one attribute, some combination of the four attributes, or all four attributes.

Graphic Element	Description
Text description of the illustration uml013.gif	Use case model diagrams summarize all the use cases in a particular domain, such as Internal temporary LOBs. Where diagrams are too complex to fit on one page, we have divided the diagram into two parts. No sequence is implied in this division.
Text description of the illustration uml014.gif	This marker indicates that the diagram is continued.

Links in Online Versions of this Document

The online (HTML and PDF) versions of these diagrams include active areas that have blue perimeters or look like buttons. You can use these links to traverse the following relationships:

• To move between Use Case Model Diagrams that encompass all the possible use cases for a given interface, and the Use Case Diagrams that detail the individual cases.

• To traverse different branches of a use case that can be implemented in more than one way. The branching Use Case Diagrams have titles such as "Three Ways to..." and buttons marked by "a", "b", "c".

• To access the sub-use cases that are entailed as part of a more primary use case while retaining context.

• To view details of the classes that underlie use cases accessible in Java.

• To view the class structure in which specific Java classes are located (see Appendix B, "Oracle JMS Interfaces, Classes and Exceptions").

The following examples illustrate these relationships.

Graphic Element	Description
Text description of the illustration uml015.gif	Use Case Model Diagrams, which summarize all the use cases in a particular domain, have active areas that link to the individual use cases.
Text description of the illustration uml010.gif	Buttons in the individual Use Case Diagrams lead back to the Use Case Model Diagram

Graphic Element Text description of the illustration qapuml17.gif

Description This Use Case Diagram combines a number of the elements: JMS Administrative Interface - this button leads back to the Use Case Model Diagram AQjmsFactory - this button leads to the class diagram, which contains the method by which the use case is implemented a. Create a Topic Connection Factory with JDBC URL is the "a" branch of the use case b. Create a Topic Connection Factory with JDBC Connection Parameters is the "b" branch of the use case

Graphic Element Text description of the illustration qapuml18.gif

Description This class diagram has links to the individual class diagrams that form its components. This reduced view of the classes shows: Whether classes, interfaces, and exceptions are entailed in the interrelationship by means of the <<>>, stereotype, such as <<interface>> The name of the package in which the class is found, such as oracle.jms The name of the class, such as AQjmsConnection

Graphic Element Text description of the illustration qapuml19.gif

Description The expanded view of the class diagram: Links to the class structure diagram using the Oracle JMS Classes button, which describes its interrelationships. Although many classes share this button, each class is linked to the part of the structure specific to it. Contains the names of the attributes (fields) if they exist and are exposed (there are none in this case) Contains the name of the methods that comprise the public interface to the class