Original name Beijing
Original issue No.200206
The original page number is 4 ~ 6.
Classification number G9
Library science, information science and information work.
Replication cycle number 20030 1
University Library Management System Based on UML
Application of UML in Digital Library
Jin yang yi zong ying
(Institute of Information Science and Technology, Shanghai Jiaotong University, Shanghai 200030, China)
Author Jin Yi/Yang Zongying
Author brief introduction Jin Yi, Yang Zongying, Institute of Information Science and Technology, Shanghai Jiaotong University, Shanghai 200030.
The research of digital library is in the ascendant. At present, it is in the transition stage from traditional library to digital library. In the process of transformation, it is necessary to apply and integrate the latest information technology to realize the most effective use and enjoyment of network information resources. Traditional system analysis and design methods can hardly guarantee the efficiency and quality of development. Applying UML to the construction of digital library can speed up the development process, improve the code quality, support the dynamic business needs, and easily integrate the existing traditional library information resources. This is a promising application direction of UML.
Practical research on abstract theme
The research of digital library is developing vigorously. Now the traditional library is transforming into a digital library, which requires the application and integration of the latest information technology to maximize the use and sharing of network information resources. Traditional system analysis and design methods can't guarantee efficiency and quality. Using UML to develop digital library can speed up the development process, improve the code quality, support the dynamic requirements, and easily integrate traditional resources. This is a promising application field of UML.
Keywords: UML/ digital library
UML/ digital library
Upper guide bearing
Classification number G250.76
1 Introduction
With the rapid development of information technology and the increasing popularity of Internet-based network applications, traditional libraries are developing towards automation, networking and electronization, which is a hot spot in the development and research of network information resources. The construction of digital library involves many problems such as digitalization of information resources, multimedia database, distributed network, information management architecture and so on. It needs to effectively integrate and apply the latest information technology. How to effectively grasp and organize the macro and apply it to the development and construction of digital library is the focus of digital library research. Uml (Unified Modeling Language) is a standardized language for drawing system blueprints, which can build a visual system model for complex systems. At present, it has been accepted by OMG (object management group) and supported by many famous computer manufacturers such as Microsoft, Hewlett-Packard, IBM and Oracle. , and has been widely used in the world. The development and construction of digital library is a complex software project, which needs to integrate different operating systems, databases and application software, and there are many users and administrators at different levels, so as to meet the needs of the library from bibliographic inquiry, borrowing of ordinary and electronic books and periodicals to providing online information services and resource enjoyment. Traditional system development and integrated analysis and design methods are difficult to ensure efficiency and quality. The characteristics of UML and the demand of digital library determine that UML should have a good application prospect in digital library.
1. 1 Basic Features and Modes of Digital Library
A digital library should have the following characteristics in organizing a series of platform-independent, object-oriented and distributed digital information resources and providing related services [2] [4]:
(1) Digital library has a huge number of digital resources, and its information measurement unit is no longer KB or MB, but GB, TB or even PB. Digital resources belong to various media (such as text, images, audio, video, virtual space, etc.). ) and has a variety of storage and compression formats.
(2) Digital resources are not isolated, but interrelated and dynamic. Digital library is the unity of digital resources, which can be found and accessed through specific protocols and access methods through certain associations.
(3) The digital library must provide users with a unified access mode, so that users can obtain the information they need transparently and conveniently, regardless of the specific location of the information. The retrieval of digital resources should be intelligent and interactive, and the retrieval of full text, multimedia information and multilingual information can achieve good recall and precision.
(4) The digital library is built on a heterogeneous platform and has a distributed and open information structure. High-speed and reliable network environment is the basis of its operation. It breaks through the limitation of time and space, and allows users to obtain the information they need anytime and anywhere. On this basis, the navigation and personalized services provided make the service content more diverse and the service methods more extensive, which is a breakthrough of the traditional library service function.
The mode of digital library can be simply illustrated by figure 1 Users connect to the consulting system of digital library through network and communication system. Through this unified access interface, users can obtain various information resources transparently.
attached drawing
Figure 1 Digital Library Mode
1.2 Overview and characteristics of UML
UML is a standardized language for drawing system blueprints, which can visualize, explain and construct system models of various components of large-scale complex systems, and establish various required documents. UML establishes the system model through use case diagram, static structure diagram (object class diagram, object diagram, component diagram and configuration diagram) and dynamic behavior diagram (sequence diagram, collaboration diagram, state diagram and activity diagram), which can visualize the system from different abstract angles. UML has the following characteristics [1]:
(1) object-oriented. UML supports the main concepts of object-oriented technology, provides some basic model elements and methods, and can express various concepts of object-oriented concisely.
(2) Visualization and strong expressive ability. The model diagram of UML can clearly represent the logical model and implementation model of the system, and can be used to model various complex systems.
(3) independence and process. UML is a system modeling language, which is independent of the development process.
(4) Independent of programming language. The software system model established by UML can be realized by any object-oriented programming such as Java, VC++ and Smalltalk.
(5) Easy to master and use. UML has clear graphic structure, simple modeling and easy to master and use.
Using UML analysis and design system can speed up the development process, improve code quality and support dynamic business requirements. UML is suitable for all kinds of system development, which can promote software reuse, easily integrate existing systems and effectively deal with all kinds of risks in development.
Application of UML in Digital Library
UML is a modeling language and an integral part of system development. There are no definitions and symbols about the concept of development process. With the support of Rational, Booch, Jacobson and Rumbaugh, the founders of UML, integrated the advantages of various system development processes and put forward a new object-oriented development process called RationalUnified Process (RUP). The core workflow of RUP process includes: business modeling, requirements analysis, system analysis and design, implementation, testing and system configuration. The following analyzes and constructs the digital library model through UML, and describes it in combination with the Rational unified process. Graphics are drawn by Rational Rose tool software.
2. 1 business modeling and demand analysis of digital library
The purpose of business modeling and demand analysis is to evaluate the digital library, collect and analyze the requirements of the system, understand the problems to be solved by the system, and fully consider the practicability of the system. The results can be represented by a use case model (Figure 2), in which participants represent external units interacting with the system, including users, library staff and external information sources; Use case is a description of system requirements, expressing the functions and services provided by the system, including purchasing subsystem, cataloging subsystem and circulation subsystem. For digital library, the circulation subsystem should also consider the difference between ordinary books and periodicals circulation and electronic books and periodicals circulation. Electronic books and periodicals refer to electronic books whose contents are in digital format, distributed electronically, read and stored by computers, and can realize the functions of full-text retrieval, page annotation, abstract, font scaling and so on that ordinary books and periodicals do not have. Users can borrow and return books online anytime and anywhere, which is an important part of digital library service function and an extension of traditional library service function. The key is that the circulation subsystem must be able to protect and control the copyright of electronic books and periodicals and the number of users who can borrow them.
attached drawing
Figure 2 Use case model of digital library
The solid line between model elements in Figure 2 indicates that there is an association relationship between them, while the solid arrow lines with hollow arrows indicate that there is a generalization relationship. There are two situations, one is the relationship between generality and particularity, such as the relationship between "circulation subsystem" and "general book circulation" and "electronic book circulation"; The other is to use association, that is, one model element needs to use another model element, and the arrow line is marked with < < use > >. For example, the circulation subsystem needs to use the bibliographic data generated by the cataloging subsystem. Figure 2 is the use case model of the digital library system layer, which only contains the most basic use case model and is a high-level abstraction of the system. In the development process, with the deeper understanding of the system, the use case model can be refined from top to bottom and evolved into a more detailed use case model.
2.2 Digital Library System Analysis and Design
System analysis and design is to study the implementation environment and system structure to be adopted, and the result is an object model, that is, a design model, which contains the realization of use cases and can show how objects communicate and operate with each other to realize the use case flow. The static structure of the system can be described by object class diagram, object diagram, component diagram and configuration diagram. The dynamic behavior of the system can be described by sequence diagram, coordination diagram, state diagram and activity diagram. These charts and supporting documents together constitute a complete design model.
Analysis and design of (1) static structure
Digital library has a large number of digital information resources, which are multimedia, multi-format and interrelated. Its data volume is large, the information length is uncertain, and unstructured information and structured information coexist. Traditional database and information management system are difficult to manage and operate these digital information resources in data model, system structure and user interface, which determines that digital library must adopt object-oriented method to establish data model and management model, establish object-oriented database and realize object-oriented information management system. Using UML to analyze and design the object-oriented digital library system can grasp the characteristics of digital library information resources from the first step of development and lay a good foundation for the next concrete realization. When building a model for the digital library system, it is necessary to deal with a large number of model elements, such as object classes, interfaces, components, nodes, graphs and so on. It can organize semantically similar model elements together. This is a package of UML, which organizes and manages the system model of digital library from a higher level.
In the detailed design stage, all classes and objects in the package diagram can be further refined from the perspective of implementation, and specific object class diagrams and object diagrams can be drawn. Fig. 3 is a package diagram of the digital library system. The dashed arrow lines illustrate the dependencies between packages. For example, the "loop" package depends on the "database" package, and the classes and data in the "database" package should be used. The solid arrow line with hollow arrow indicates the generalization relationship between packages, here is the general and special relationship, such as the generalization relationship among cataloging packages, library cataloging packages and joint cataloging packages.
attached drawing
Figure 3 Digital Library System Package Diagram
(2) Analysis and design of dynamic structure
All kinds of services provided by digital library are based on distributed and open information structure, and are completed by high-speed and reliable network environment. Each service can be regarded as an event stream, which is completed by the interaction and cooperation of several related objects. The cooperative relationship and process behavior in this system can be observed and understood by drawing sequence diagrams and collaborative diagrams.
The state sequence experienced by an object during its existence is very important for grasping the behavior and state transition of the object. We can know the history of an object, the events that lead to the transition from one state to another, and the actions caused by the state transition through the state diagram.
In addition, in order to describe workflow and concurrent processing behavior, activity diagram can also be used to express the control flow from one activity to another.
Sequence diagram and collaboration diagram are suitable for describing the cooperative behavior of multiple objects, while state diagram is suitable for describing the behavior of an object across multiple use cases. The difference between state diagram and activity diagram is that state diagram describes the external behavior of object class in response to events, while activity diagram describes the behavior of object class in response to internal processing.
attached drawing
Fig. 4 Sequence diagram of electronic books and periodicals circulation service in digital library
Fig. 4 is a sequence diagram example of electronic book circulation service, which is used to explain the basic electronic book circulation service of digital library. The user logs into the user interface of the circulation subsystem, and after being verified by the user, submits a service request to the e-book circulation module of the circulation subsystem. E-books need copyright and number verification to ensure that only one user is allowed to borrow or read each e-book at the same time. For example, if you buy five e-books, five users can borrow or read the book at the same time. You must be able to control users to copy and print e-books at will to protect the legitimate rights and interests of e-book publishers. Then you can complete the circulation services such as borrowing, returning, ordering and renewing, and finally quit.
Through the sequence diagram, we can clearly see the message exchange between users in chronological order, and the user interface of the circulation subsystem and e-book circulation module, which is very helpful to grasp the control flow, sequential behavior and interactive behavior of the system. The event flow and control flow of digital library established in distributed and network environment are very complex, which need to be decomposed step by step from top to bottom, and analyzed and explained by several diagrams that can reflect the dynamic structure.
2.3 Digital Library Implementation, Testing and System Configuration
After system analysis and design, we can realize the system in a specific environment according to the design model, generate system source code, executable programs and corresponding software documents, and establish an executable system. Then the system needs to be tested and debugged to ensure that the system meets the predetermined requirements and obtains an error-free system implementation. The test results will prove that the complete system can be really used. Finally, the task of system configuration is to configure and debug the system in the real running environment and solve any problems that may exist before the system is officially used.
3 abstract
The development of digital library is in the ascendant. At present, it is in the transition stage from traditional library to digital library. In the process of transformation, it is necessary to apply and integrate the latest information technology to realize the most effective use and enjoyment of network information resources. Traditional system analysis and design methods are difficult to ensure efficiency and quality. Applying UML to the construction of digital library can speed up the development process, improve the code quality, support the dynamic business needs, and easily integrate the existing traditional library information resources. This is a promising application direction of UML.
refer to
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[4] Chen Ying. Research on the application of UML multi-view modeling mechanism. Journal of beijing institute of technology.2001,(2)
Yu shengfeng. Research on key technologies of digital library. Journal of China Science and Technology Information Society, 1999, (12)