"Software Engineering--theory, Method and practice"--a summary of the eighth chapter object-oriented design

The 8th chapter Object-oriented design

Analysis Model : Functional model, analytical object model, dynamic model.

First, the concept of design

Design Activity Design is also a modeling activity, it is based on the analysis model to achieve the implementation of the environment of the class modeling, State diagram modeling, collaborative modeling, component modeling, deployment modeling, persistent modeling and user interface prototype, to achieve from the requirements analysis to the software implementation of the leap.

The design activities are divided into two main stages, such as system design and detailed design.

Modularity of the system means that a complex large system is decomposed into a few relatively simple smaller parts called subsystems. A subsystem is a well-defined software component that provides multiple services to other subsystems.

Hierarchical decomposition of the system, sub-systems divided into different levels, each level of the use of low-grade services provided, and to provide high-level services. Another form of system decomposition is the decomposition of systems into peer subsystems, each of which is responsible for a different type of service subsystem that is independent of each other.

The coupling degree represents the degree of association between two subsystems. When one subsystem changes, the effect on the other subsystem is very small, it is called loosely coupled, and conversely, tightly coupled. The lower the coupling, the better.

The external subsystem accesses the syntax analysis tree in two ways: one is to use the attributes of the parse tree, and the other is to invoke it through an action.

Cohesion is the degree of correlation within the subsystem.

The goal of the system design is to divide the subsystems and make the subsystems low-coupling, so as to improve the understanding and maintainability of the software.

Second, the software system structure

Software architecture involves the overall organization of software systems, global control, data access and communication protocols between subsystems.

Warehouse Architecture , there are two different pieces of software: A subsystem that represents the current central data structure and a set of independent processing centers.

Hierarchical Architecture hierarchy is a concept that organizes software designs into chromatography or collections of classes or components to accomplish a specific purpose on a class or component at the same level.

MVC Architecture in MVC architecture, carefully divided into three different types: The model subsystem is responsible for the central data of the storage system, the view subsystem is responsible for presenting the data in the model to the user, and the controller subsystem is responsible for managing the interaction control with the user.

client / two forms of server architecture : Thin client model, fat client model.

In the pipeline and filter architecture , data flows between different subsystems, each of which processes the input set of data and outputs the processing structure to other subsystems. This is, the subsystem is called the filter, the subsystem sees the contact called the pipeline.

Third, the system design

During the system design phase, when the software architecture strategy is selected, the analysis classes in the analysis model need to be compared to the design elements of the design model. After you determine the design element, you need to describe the behavior of the subsystem, which is precisely the set of interface operations.

Common data storage Management has 3 ways: Data file, relational database, object-oriented database.

Deploy the subsystem.

System Design Review.

Detailed Design : Method modeling ( method naming, method visibility, Method Modeling of Borrowerinfo Class), attribute modeling, State modeling, relational modeling.

v. Application design mode : Abstract Factory mode,Adaptor mode,Bridge mode, facade mode.

VI. User interface Design

User design principles: User-controlled, consistency, personalization, latitude, feedback, aesthetics and usability.

"Software Engineering--theory, Method and practice"--a summary of the eighth chapter object-oriented design