Shulou(Shulou.com)06/02 Report--

How to use UML, many novices are not very clear about this, in order to help you solve this problem, the following editor will explain for you in detail, people with this need can come to learn, I hope you can gain something.

Friends who come into contact with UML for the first time may find its various lines, relationships, descriptions and so on obscure. A brief introduction to some of the pictures, with the most simple language combined with pictures so that you can understand them at a glance, if you find mistakes in the process of reading, please point them out in the comments section.

1. Class diagram, object diagram, interface

These three pictures are the simplest in uml. I think you can understand by looking at the following three pictures:

There are several relationships in the class that we must master:

Generalization relationship: represents the inheritance of class to class, the inheritance of interface to interface, and the implementation of class to interface.

Relationship: the relationship between classes. One class holds the properties and methods of another class. It can be one-way or two-way, but two-way is not recommended.

The association also includes an attribute: cardinality. The cardinal number shows that there can be several examples of the class in this section. For example, there must be only one Tang monk, but the apprentice can have many. We can use the following figure to show

Aggregation relationship: it belongs to a kind of association relationship, which represents the relationship between the whole and the individual. For example, a computer is made up of a screen, a keyboard, a mouse, etc.

Synthetic relationship: it is also a kind of correlation, but its relationship represents the strongest, for example, people are made up of brain, heart and limbs (when distinguishing polymerization and synthesis, you can imagine that the inseparable relationship is similar to that of the human body. Similar to the machine can be changed for polymerization)

Dependency: dependency is different from general relationship in that one class holds the property or method of another class, while the method parameter in the dependency class is another class.

two。 Component diagram

Component diagrams can be understood simply as physical components in a system. Such as packages, class files, configuration files, style files, and so on. For the learning component diagram, please see the following figure:

3. Deployment diagram

The deployment diagram can be simply understood as the configuration of the hardware and how the software is deployed in the network structure (for example, how many tomcat, how many mysql, how many redis, and which server they are deployed on in a program). Let's take a look at the following figure to learn:

4. Use case diagram

The main function of the use case diagram is to collect the requirements of the system, including internal and external influences (for example, the users of the system are divided into n roles, what each role can do) the following figure takes the functions that a user can use as an example

5. Time sequence diagram

The timing diagram is used to describe the flow order of messages between objects. Here is a simple registration process as an example:

In this picture, the vertical dotted line is called the lifeline, which represents the existence time of an object. Each arrow is a call. The white bar on the lifeline is called the activation bar. The activation bar represents the duration of the call.

6. State diagram

The state diagram describes the process of changing the state of an object from start to finish. The following is also an example of the registration process above:

Is it helpful for you to read the above content? If you want to know more about the relevant knowledge or read more related articles, please follow the industry information channel, thank you for your support.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.