UML Learning (2)
Tomorrow, we will start our practical training and build a library management system. I find it difficult to use the java interface, database data, and jdbc connection! Hi, it's still hard to master the knowledge. How much can be done? Ask the teacher if you're fine. Try to catch up with large troops! Now it's all taken away. If you are not good at learning, you will be dumped farther and farther away!
Today we are talking about a lot of things, including the plotting of several types of graphs, the sequence diagram, the activity diagram, the state diagram, and the Collaboration diagram.
(1) Basic concepts in the sequence diagram
Activation: a sequence diagram describes the activation and passivation of an object. activation indicates that the object is occupied to complete a task. passivation indicates that the object is idle and waiting for a message. in UML, when an object is activated, the lifeline of the object is extended to the moment. A rectangle is called a plan bar or a control period. the object is activated at the top of the activation bar. the object is inactive after it completes its work.
Object creation and destruction: In the sequence chart, the default position of the object is at the top of the graph. this indicates that the object already exists before the interaction starts. if the object is created during the interaction process, put the object in the middle. if you want to cancel an object, place the "X" symbol at its lifeline termination point.
(2) Basic concepts in the activity diagram
Action status: An atomic, non-disruptive action that changes to another action after the action is completed. in UML, the action State is represented by a rounded rectangle, and the Action indicated by the action state is written inside the rounded rectangle.
Branch and merge: branch is common in software systems. it is generally used to indicate the conditional behavior of the object class. use a Boolean expression to determine the direction of the action. conditional behavior is expressed by branch and merge. in the activity diagram, the branches are represented by a small hollow diamond. the branch includes one inbound conversion and two conditional outbound conversions. The output conversion conditions should be mutually exclusive and ensure that only one outbound conversion can be triggered. the merge operation includes two conditional input transformations and one output conversion.
Forks and Confluence: forks are used to describe concurrent threads. Each forks can have one input conversion and two or more output conversions. each conversion can be an independent control flow. confluence means that two or more concurrent control flows are synchronized. When all the control flows reach the confluence, the control can continue. each confluence can have two or more input transformations and one output conversion. use a rough straight line to represent a branch and sink in UML
Swimming track: the swimming track divides activities in the activity chart into several groups, and assigns each group to the business organization responsible for this group of activities. the swimming track distinguishes the objects in charge of activities and clearly indicates which activities are performed by which objects. each activity explicitly belongs to a swimming pool. in the activity diagram, the swimming pool is drawn by vertical solid lines, and the area separated by vertical lines is the swimming pool.
(3) Basic concepts in the state chart
State: the State name is represented by a rounded rectangle. The state name is usually represented by a string. the name of a State must be unique in the context where the state chart is located.
Conversion: uses a straight line with arrows to indicate that one end is connected to the source State and the other end is connected to the target State.
Initial status: Each status chart has an initial status. this status indicates the starting position of the status chart. the initial status can only be used as the conversion source, not as the conversion target, and only one status chart can be used. the initial State is represented by a solid circle.
Termination status: the final state of the model element. It is the end point of a state chart. There can be multiple termination statuses in a state chart.
It also introduces the most important steps of software development.
Software lifecycle Overview:
Software life cycle: the life cycle from software generation to decommission
Definition of problems, feasibility analysis, overall description, system design, coding, debugging and testing, acceptance and operation, maintenance upgrade to obsolete stage in the software life cycle
With the maturity of new object-oriented design methods and technologies, the Guiding Significance of software lifecycle design methods is gradually decreasing.
Detailed description of the software lifecycle:
1. Problem definition and planning (and Software Development Plan)
Mainly determine the software development goal and its feasibility.
2. Requirement Analysis (requirement analysis manual and initial user manual): Determine the Software Development Feasibility
Detailed analysis of each function. The demand analysis stage is a very important stage.
The success of the entire software development project lays a good foundation.
3. Software Design (Outline Design and detailed design): this stage mainly sets up the entire software system based on the requirements analysis results.
Such as system framework design and database design. Software design is generally divided into the overall design and detailed design.
4 program code (submit the source program and list): This stage is to convert the software design results into computer executable program code.
It is necessary to develop a uniform program code that complies with standard compiling specifications. To ensure the readability and maintainability of the program
High program running efficiency.
5. Software Testing (submit the software maintenance test report): After the software design is complete, the software must undergo rigorous testing to find
Problems in the design process and correct them. Unit testing (white box) and integration testing (black
And system testing. The testing methods mainly include white box testing and
Black box testing. Random. A detailed test plan should be established during the testing process and tests should be carried out in strict accordance with the test plan to reduce
Less Test
6. Run maintenance (submit software maintenance report): software maintenance is the longest stage in the software life cycle. In the software
After the development is completed and put into operation, the software cannot continue to meet user requirements due to various reasons. To continue the software
The service life must be maintained for the software. Software maintenance includes corrective maintenance and corrective maintenance.
