[Two], UML basics

UML Overview

UML is a general purpose visual modeling language , a programming language is different from that used to model the system through some standard text and graphic symbols . It is used to describe software, visualization, structured document software system . It is a summary of the experience of the previous modeling techniques and to absorb the standard method for modeling the most outstanding achievements .

UML structure

view

User view : the user's point represent the target system, which is the core of all views, the view needs to describe the system.
Structural view : represents the static behavior of the system, the system described static element, such as a bag, and the relationship between the classes and objects thereof.
Behavioral view : that the constituent elements of the dynamic behavior of the system description of the system, such as the interactive relationship between objects in the system is running.
Implementation view : said relationship between them and the description of the file system in a distributed system of logic elements.
Environmental view : showing the relationship between the system they describe hardware and the distribution system of physical elements.

Map

Use Case Diagram
Class diagram , an object diagram, FIG package, the combination structure of FIG.
A state diagram, an activity diagram, a sequence diagram, communication diagram, a timing chart, an overview of FIG interaction
Component diagram
Deployment diagrams

Model elements

Model elements include the relationships between things and things and things
Things are an important part of the UML, it represents anything that can be defined
The relationship between things put things together to form meaningful structural model
Each element has a model with the corresponding graphic elements
A model with a different element can be used in the UML diagram
But no matter what the figure, the same model elements remain the same meanings and symbols

Universal Mechanism

It provides a general mechanism for UML model elements to provide additional comments, and other semantic information , including expansion mechanism , allowing the user to extend the UML.

Class A and FIG.

Class (Class) encapsulates the behavior and data , are an important part of object-oriented.
Class having the same attributes, operations, general term for a set of object relationships .
In the system, each class has a certain responsibility, responsibility refers to the class as a task of class to complete what kind of function, to assume what kind of obligations. A class can have a variety of responsibilities, a well-designed class is only one general duties .
I.e., the class and the attribute data functions , i.e., the operation of the class and the behavior of functions .
FIG class present in the system using different classes describe the static structure , which is used to describe the relationship between them and the different classes .

UML class icon

In UML class diagram, class generally consists of three parts:

The first part is the name of the class : Each class must have a name, class name is a string

In accordance with the naming conventions of the Java language class name first letter of each word are capitalized .

The second part is the attribute class : class attribute refers to a member variable nature, i.e. class. A class can have any number of attributes, the attribute may be omitted.

In accordance with the naming conventions of the Java language, property name in all lowercase the first word, after each word capitalized (hump nomenclature)