Research On Design Patterns And It's Application In The Design Of Chart Class Library

Studies,research and application of design patterns are a hot spot.The idea of object-oriented is the main technology of software design;design patterns summarizes the most important design experiences in many a good object-oriented software and records them by standard form,and provides solutions to similar problems.Design patterns is the base of object-oriented reusable software,and it can make it easier and more convenient for people to reuse successful designs and system structures. Specifically speaking,design patterns is the way to solve problems in specific environment by using object-oriented technology,and it is the outcome of collective wisdom of entire software industry.In this dissertation,the research mainly includes collaboration between design patterns,decomposition of design patterns,flexible application of design patterns,and design patterns'support for changes.On the basis of research in the design patterns,this paper introduces a small self-developed Java Chart Class Library ,named MiniChart, which provides the construction and operation of various chart-objects,and support the show of following charts:Timeseries-Chart, Line-Chart, Point-Chart, Histogram, Pie-Chart, and Gantt-Chart. MiniChart is the useful extension of the basic Java Class Library of graphics API, and provides convenience to visualized analysis and display of a large number of data.In the design of MiniChart,design patterns serves as a guide,which makes MiniChart more compact,flexible,easily cutting, expansible and reusable.Firstly,the ideas and research of design pattern is introduced,including concept,principles,classification,and relationship between the design pattern and object-oriented idea,and the relationship between the design pattern and framework, and more attention is paid to the application research of design pattern; Secondly,the functional requirements ,MiniChart's object compages model and the design of framework of MiniChart are described;Finally,the application of design pattern in MiniChart is elaborated,and the application of following patterns in MiniChart is stressed:Observer Pattern, Mediator Pattern, Composite Pattern,Simple Factory Pattern, Command Pattern,Factory Method Pattern and Builder Pattern.