uml

问题 How can I generate UML diagrams (especially sequence diagrams) from existing Java code? 回答1: ObjectAid UML Explorer Is what I used. It is easily installed from the repository: Name: ObjectAid UML Explorer Location: http://www.objectaid.com/update/current And produces quite nice UML diagrams: Description from the website: The ObjectAid UML Explorer is different from other UML tools. It uses the UML notation to show a graphical representation of existing code that is as accurate and up-to-date

问题 What is the difference between include and extend in a use case diagram? 回答1: Extend is used when a use case adds steps to another first-class use case. For example, imagine "Withdraw Cash" is a use case of an Automated Teller Machine (ATM). "Assess Fee" would extend Withdraw Cash and describe the conditional "extension point" that is instantiated when the ATM user doesn't bank at the ATM's owning institution. Notice that the basic "Withdraw Cash" use case stands on its own, without the

问题 What is the difference between association, aggregation, and composition? Please explain in terms of implementation. 回答1: For two objects, Foo and Bar the relationships can be defined Association - I have a relationship with an object. Foo uses Bar public class Foo { void Baz(Bar bar) { } }; Composition - I own an object and I am responsible for its lifetime. When Foo dies, so does Bar public class Foo { private Bar bar = new Bar(); } Aggregation - I have an object which I've borrowed from