Strictly in stages
The development and design of the system is a big project, so the whole system development and design process should be divided into several stages, and the corresponding stages should be divided into several different steps, and each stage and step should have clear work tasks and objectives. This orderly organizational arrangement has clear regulations and distinct levels, which facilitates the formulation and control of plans, lays a solid foundation for follow-up work and improves work efficiency and quality.
Take a systematic view to deal with it.
In the system analysis stage, based on the comprehensive investigation and analysis of the original system, the best logical model of the system is constructed, so that users can have a preliminary understanding and understanding of the outline of the future complete system, so as to communicate and discuss with users in time and continuously improve the perfection of the system. On this basis, the physical realization and design of the system are carried out, and the specific functions of the logic model are effectively completed. Logical design and physical realization complement each other and are inseparable, which makes the system design safer and more reasonable.
The design of the whole system mainly adopts rapid prototyping method.
Rapid prototyping is an important method of information system design. According to the needs of users, users and developers jointly determine the basic needs and main functions of the system, and establish an experimental and simple information system model in a short time. Through users' opinions and suggestions, the model is constantly modified and improved until users are satisfied, thus forming a relatively stable and ideal management information system. The main advantages of this method.
1. The context is clear, and all the problems revolve around a model, which makes the two closely related.
2. It helps to discover the needs of users, and through the contact with prototypes and users, it can inspire developers to explore problems, so as to constantly revise and improve and finally get an ideal system.
3. The system development efficiency is high. This method is short in development cycle, flexible in use and easy to modify, and is suitable for managing systems with unstable systems.
4. The scalability of the system is good, because this method is constantly developed and perfected in the prototype application, so it has strong scalability.
When designing code, follow the following principles.
Uniqueness: In this system, each code is uniquely determined by each object in the system.
Standardization: mainly embodied in the standardization of naming program file names and data files, following the principle of simplicity, conciseness and convenience. Be clear at a glance, do not repeat. In order to facilitate system maintenance personnel, a unified standard is used.
Rationality: The coding design in the system adapts to the classification of the coded object, so that the coding can mark the classified data of the coded object.
Simplicity: code separation after code is adopted in the design process, so that the database operation code is separated from the front-end calling code, and the page modification is easy.
Adaptability: in the process of code design, the code embodies the characteristics of the coded object, which is easy to identify and remember, easy for system maintenance personnel to understand and master, and easy for maintenance work.
Overall functional structure of the system
The network communication system includes the following main functions.
User registration; User login;
Find friends; View friends' information;
Add friends;
Delete friends;
Send a message;
Send files.
The database table is mainly used to store user's registration information and user's friend information, and two database tables can be used to store user information and user's friend information. Including the user's number, nickname, password, online or not, ip address, information, avatar number, gender, email and native place. Among them, user nickname and password are required fields; Online or not is automatically set by the system; The remaining information is optional.
The whole project takes JAVA as the platform, uses Eclipse development tools, uses SQL Server 2000 to manage database data, and develops a centralized network communication system based on Socket. The system is designed in client/server (C/S) mode, which is a three-tier C/S structure, including database server, application server and application client. The system adopts C/S structure, which can reasonably assign tasks to client and server, thus reducing the communication overhead of the system.
Customer level.
The client layer is the user interface part of the application, which is responsible for the dialogue function between the user and the application, and is used to check the input data of the user and display the output data of the application. In order to operate intuitively, the client layer needs to use a graphical user interface. If the chat user changes, the system only needs to rewrite the display control and data checking program, without affecting the other two layers.
Service layer. (functional layer)
The service layer is equivalent to the application ontology, that is, programming specific business processing logic. In application design, it is necessary to avoid multiple data exchanges between presentation layer and function layer, which requires one-time business processing as much as possible to optimize the overall design.
Data layer
The data layer is a database management system, which uses Microsoft's SQL Ssever2000 database server to manage data. SQL Ssever2000 can quickly update and retrieve a large amount of data, so it is transferred from the functional layer to the digital layer.
According to the requirements of the layer, SQL language is generally used.
This is part of my graduation thesis. What I do is a chat system for your reference. It doesn't matter whether you give it or not ~! It is impossible to bring all the codes to you. It's 20 megabytes