UML-based information system analysis and design
Liu Ming
Abstract: This article takes a library information system as an example to explore problems such as object-oriented analysis, design and implementation of unified modeling languages. First, the basic idea of object-oriented, summarizes the syntax semantics mechanism and its advantages of UML. UML has broad application prospects, this paper surrounds the development of the library information system, the application of UML-oriented modeling in information system analysis and design process has been described in more detail.
Keywords: UML object-oriented information system modeling
Analysis and design of information system based on UML
Liu Ming
Abstract: This paper discusses some questions about object_oriented analysis and design by UML, and an example about library information system is given in the paper First, Object_oriented fundamental concepts are talked Then phrasing and semantic of UML are also presented with its advantage It's... .
Keywords: UML, Object_orient, Information System, Modeling
I. Introduction
With the continuous development of computer science and technology, computer technology penetrates into various fields. Similarly, the development of the information system is no exception. Collect, store, transfer, analyze the input, stored, transmit, analyze the input, and output a useful information called an information system. Although the traditional life cycle method has brought huge progress to the software industry, some mitigated the software crisis, but it turns out that this methodology still has more significant shortcomings. Compared to other analytical and design methods, there is a great advantage for object-oriented methods, and it is increasingly valued. This paper will explain the idea of object-oriented methodology and its embodality in UML in conjunction with the analysis and design process of the book information system.
Second, the main point of view
The starting point and the basic principle of object-oriented methodology is to simulate the way of thinking of human habits, so that the method and procedure of development software as close as possible to the method and process of human understanding of the world to solve problems, so that the problematic space and implementation of the problem The solution is as soon as possible.
Anything can be seen as an object, and the complex objects are combined by simple objects in some way. Each object is a unity of static properties that will describe its characteristics or status and dynamic behavior to which it is defined above attribute is packaged together. Object is a separate entity that changes in its attribute value can only be done by defining operations (packaged behavior) on attributes. It provides services to other objects, or you can apply for other objects to serve request information only between the objects. When an object receives a service request of another object, it is determined whether or not to respond to its request and feedback to the applicant in a certain manner.
Abstract similar characteristics in the objective world and ignore their respective details, and portrait their total
Sex, defined as classes. The same property is the same attribute and its behavior, and the object-oriented methodology has achieved their differences through the details of the inheritance.
The development of the system is often experienced for a long period of time, from the user's demand to the system,
Design, implementation, and final maintenance. Object-oriented methodology also includes object-oriented analysis, design and implementation.
Third, UML modeling language
1, concept
UML is a standard graphical modeling language that is a standard representation of object-oriented analysis and design. UML only defines some pictures and their meaning, and its idea is not related to the method. People can use UML in various ways, regardless of how the method changes, their foundation is the UML map, which is also the end use of UML - the unified exchange standard for people in different areas. Regardless of the different methods or processes taken by analysis, design and developers, the design products they submit are described in UML, which is conducive to promoting mutual understanding.
UML combines the successful experience of object-oriented method practices, and packages them in the form of modeling languages, adapting to the development of large complex systems. UML is powerful, but people often confuse their concepts, it is:
Not a visual programming language, but a visualized modeling language;
Not the specification of the tool or knowledge base, but a modeling language specification;
. Not a process, not a method, but allow any process and method to use it;
2, design goals
Before UML was born, there was no unified standard for software product development, and people attempted to use different methods to analyze and design systems, resulting in a variety of analysis and design methods. The emergence of UML has brought a lot of convenience to the software development process.
. Easy to use, strong expressive ability, perform visual modeling;
. Unrelated to specific implementation, can be applied to any language platform and tool platform;
Norway with specific processes, can be applied to any software development process;
. Simple and scalable, expanded and exclusive mechanism, easy to expand, no need to modify the core concept;
. Support for high-level concepts emerged as object-oriented design (such as collaboration, framework, pattern, and components), emphasizing reuse of architecture, framework, mode, and components in software development;
. Integrate with the best software engineering practice;
Can be upgraded, with broad applicability and availability;
. It is conducive to the market growth of the object tool.
3, UML architecture
UML is composed of a map and meta model. The figure is the syntax of the UML, and the metamodel is given the meaning of the map, which is the semantics of UML. UML is used to describe models, which use models to describe structural or static features, as well as behavior or dynamic features. It models different views (view) from different perspectives, forming different views (view), including:
Use the case view, emphasizes the system function you see from the user's perspective, this
View is also called user model view:
. Logical View, showing static or structural composition and characteristics of the system, also known as structure model
Structural Model View or Static View;
. Concurrent View, reflects the dynamic or behavioral characteristics of the system, also known as behavioral models
BEHAVIORAL MODEL View, Process View Collaborative View (Collaborative),
Dynamic view;
Component View, reflects the structure and behavioral characteristics of the system, also known as implementation
Implementation View and Development View; Download and Download Counterclags (DEVELOPMENT VIEW);
Deployment View, reflects the structure and behavioral characteristics of the system to realize the environment, also known as the ring
Implementation Model View or Physical View;
Each UML view is composed of one or more pictures (diagram), one picture is the system architecture
A side representation, it is consistent with other pictures, all of which constitute a complete view of the system together. UML
For nine different maps, it can be divided into two categories, one is a static map, including example, class diagram, object map,
Component diagram, configuration diagram: Another type is a dynamic diagram, including a sequence diagram, a collaborative diagram, a state diagram, and a movable diagram. You can also
According to their applications in different architectural views:
Use an example (use case diagram) describes the functionality of the system;
Class Diagram, describing the static structure of the system;
Object Diagram, describes the static structure of the system at a certain moment;
Sequence Diagram, description of the interaction between system elements in chronological order;
COLLABORATION DIAGRAM, description of the interaction between system elements in order of time and space
And the relationship between them;
State Diagram, describes the status condition and response of the system elements;
Activity Diagram, describes the activity of system elements;
Component Diagram, describes an organization that implements an element of a system:
Deployment Diagram, describes the configuration of environmental elements, and reflects the element of the system
Bread to the configuration.
4, UML application field
UML is used to model system modeling, which can be applied very widely, which can describe many types of systems, commonly used information systems, technology systems, embedded real-time systems, distributed systems, and more. It can also be used in different stages of system development, from demand specifications to tests that have completed system.
UML's application runs through five phases developed in system development, they are:
. demand analysis. UML's use case view can represent customer needs. By modeling with example, you can be external to the outside
Color and the modeling of the system they need. Roles and use cases are the relationship between them, communication modeling
of. Each usage specifies the customer's needs: he or her needs system;
. analysis. The analysis phase mainly considers the problem to be solved, and can be described using the logical view and dynamic view of UML:
Class diagram description system static structure, collaboration diagram, state diagram, sequence diagram, activity diagram, and state diagram system
Dynamic characteristics. In the analysis phase, only for the problem of the problem area - does not define software system solutions
Details of the case (such as the class, database, etc.);
. design. In the design phase, the results of the analysis phase expand into a technical solution. Join new classes to provide
Technical infrastructure - user interface, database operation, etc. The problem of the analysis phase is embedded in this
Technical infrastructure. The result of the design phase is a detailed specification of the construction phase;
. structure. In the stage of construction (or program design phase), convert the class of the design phase into some object-oriented program
Design language code.
. test. Testing to system is usually divided into unit testing, integrated testing, system testing and receiving tests.
same level. Unit testing is a test of several classes or groups, usually by programmers; integrated test sets
Enter components and classes to confirm whether they are properly collaboration; system testing as a "black box",
Verify that the system has all the features required by the user; accept the test by the customer, and the system test class
Similarly, verify that the system meets all the needs. Different Test Teams use different UML maps as the foundation of their work: unit test use class diagrams and class specification, integrated test typically use component diagrams and associations
Motto, and system test implementation use case diagram to confirm the behavior of the system comply with the definitions in these figures.
The following will be explained in an application to use the UML analysis and design system in an application.
Third, library information system UML instance
The library information system mainly handles books and magazines borrowings and preservation. Below is the needs of the information system
Ming, is done by the user and the developer.
Library tells the readers, readers and books, and magazines, must be registered in the system;
The library is responsible for purchasing books, and it is generally necessary to buy more for popular books. If the old book or magazine expires
Or very bad, you can remove it from the library.
The library administrator is an employee of the library, which is responsible for dealing with customers (borrowers), and their work should be supported by the system.
Borrowers can book the book or magazine that is currently not borrowed, and once the scheduled book is returned to the library or library
When the new purchase is arrived, it will notify the reservation immediately.
The library can be conveniently generated, updated, and deleted systems with bibliography, borrowers, borrowings and bookings.
information.
The system should have good scalability.
1, demand analysis
The first step in analysis is to define the use case, that is, describe the function of the library system; determine the functional requirements of the system.
The use of the library information system is shown below:
Borrowed
Return to the book
Reservation
Delete
Increase title
Update or delete headings
Increasing bibliography
Delete bibliography
Increasing borrowers
Update or delete borrowers
Analysis of the library information system can be described with an example of UML. Each use case is available in the way of text
In addition, the described content includes use cases and more detailed information interacting with the role. Use case "borrow book"
Described as follows:
(1) If the branch is not booked;
a. Title
b. Bibliography under the title of this title available
C. Borrower
d. Library lending the book's book
e. Add a new borrowed record
(2) If the borrowers have been booked:
a. Marker Borrowing
b. Tag title
C. Bibliographic items under the title available
d. Library lending the book's book
e. Add a new borrowed record
f. Delete Booking Records
2, field analysis
In order to conduct a domain analysis, you need to read specifications and use cases to understand the concepts of the system to process. For more
A good understanding of the system, communicating with users, field experts, trying to determine all the concepts and concepts of all must be processed
relationship. The domain classes in the library information system include: BRROWER Information, Title, book title (Magazine Title, Bibliography (Item), Reservation, Borrow Loan.
These domain classes and their relationships are shown in class diagrams. Basic properties and movements are also in the class diagram
. Some attributes and motions are added in other images (as shown in Figure-2).
Certain types of UML state diagrams show different status of the objects of the class and events that chase the status. State map
The class is: Bibliographic and title. The state diagram of the title class is shown in Figure -3.
To describe dynamic behavior of the domain class, any dynamic UML map can be used: sequence diagram, collaboration map, or active diagram.
In the sequence diagram, how the domain class collaborates to operate the use case in the system. When these sequence diagrams are established, they will be sent
Now new and add them to classes. The sequence diagram "Bibliography" (without subscription) is shown in Figure-4.
When modeling the sequence diagram, it is clear that the window or dialog box is required as an interface to the role. In the analysis stage,
In order to separate the domain class with window classes, assemble the window class into a GUI package (called "GUI package"), assemble the domain class into a business package. In addition, I also take a name to the application, called "General Library
Application. "More specific user interface design is often carried out in the design phase.
3, design
The design phase and the last UML model are extended and refined in the design phase, mainly considering all
Technical issues and restrictions. The purpose of the design is to produce an available solution and can be easier to
The case transforms into program code. The classes defined in the analysis phase are further refined, define new classes to process technology.
Problems, such as databases, user interfaces, communication, devices, and more.
The design is generally divided into two parts:
Architecture Design: In architecture design, need to define package (subsystems), inter-package room correlation and basic communication machine
system. - A natural requirement is to get a clear and simple architecture, that is, in the architecture, the correlation should be as small as possible.
The correlation between the two parties should be avoided as much as possible.
Detailed design; refine the contents of the package, that is, described in detail, so that the programmer is based on
They are easily encoded. The UML dynamic model is used to display how objects are active in the specified case.
The library information system is divided into four packages: user interface package, business object package, database package, application package.
User Interface Pack: Use the user interface class, users can browse the system
The data is input to new data. This package works with business packages to complete the task. User interface package calling business
Operation to retrieve and insert data.
Business Object Package: Business Object Pack Contains domain classes in the analysis model,
For example, etc.. Business objects package association with database packages Complete tasks, all business object classes must be taken from data
Inherited in the persistent class
Database Package: Database Packet Provides a class in the business object package, you can
There is a place where they are saved.
Application Package: Application package provides services to other types of packages in the system.
The internal design of these four classes is shown in Figure -5.
The implementation of the inside of the package is completed in the detailed design phase, which is no longer elaborated.
Fourth, conclude
Developing and managing high quality applications in this reasonable time to become increasing
The more difficult it is. The emergence of unified modeling language UML provides powerful tools for information system modeling and design. Use
UML visual modeling software tool, we can manage project requirements in accordance with RUP requirements, use base
In the framework of the component, verify the software quality, control version update, to achieve object-oriented of the entire software system
Analysis, design and iterative development. The in-depth popularization of this technology and the application will result in the development of my country's software industry.
Very active promotion.
