I am trying to model in UML 2.0 a Java servlet application that has three classes

  • Servlet class; essentially a main class that acts as the controller
  • DatabaseLogic; contains methods for database operations
  • XMLBuilder; builds an XML from a query result string

The classes use a variety of packages from the Java library. I am unsure how to model this in UML

Do I have to create a package and show which libraries are used for each individual class or can I just have one large package in the diagram with all the libraries showing which classes have dependencies on which.

As per this diagram

enter image description here

This is my first time working with java properly (im a C++ guy)

Apart from being a bit messy , is this a correct UML representation of the system I described?

Does a Package in UML mean the same as a Package in Java?

  • 1
    Would you add arrows? ARI --makes-conn-with--> Database or Database --makes-conn-with--> ARI first would be correct for the controller I think.
    – User
    Dec 11, 2012 at 16:17

1 Answer 1


It looks like you've roughly got it right! A package in a UML class diagram does equate to a package in Java. The JVM/Java's APIs are so large that often its treated as one black box in these diagrams (or not shown at all).

Going forwards I'd worry less about the formal UML notation and more about 'does my colleague grok this'. Java class diagrams can get very complex beyond a certain size.

  • Thanks! I made some changes to make it easier to read for my colleague grok! :) Dec 12, 2012 at 12:14

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