Class Diagram

For more detailed information, please check the online help in Eclipse, it is much more exhaustive than the information here. You can get there from the Eclipse main menu by selecting Help > Help Contents. There will be a chapter for the ObjectAid Class Diagram once you have downloaded the plug-in.


The class diagrams of the ObjectAid UML Explorer are based on the OMG's UML 2.0 specification (see They can contain existing Java classes, interfaces, enumerations, annotations (collectively called classifiers henceforth in accordance with UML 2.0) as well as packages and package roots (i.e. JARs and source folders). Class diagrams only reflect the existing source code, which cannot be manipulated through the diagram. They are stored as XML files with the extension '.ucls'.

The ObjectAid UML Explorer allows software developers to document and explore Java source code and libraries within the Eclipse IDE. It supports an agile approach to software development with seamless integration into the Eclipse IDE and many ease-of-use features:

  • Create new class diagrams with a wizard.
  • Drag and drop Java types from the Package Explorer, the Type Hierarchy, the Search view or any other view that contains Java elements.
  • All relationships are reverse engineered automatically: Generalizations, realizations, associations, nesting and dependencies.
  • Associations are also determined from generic Collections and Maps or can be added manually for non-generic Collections/Maps. Two unidirectional associations can be merged into one bidirectional association.
  • Java fields can become associations when the referenced class is in the diagram, otherwise they are just attributes.
  • You can inspect javadoc and source code for any type in your diagram in the Javadoc and Declaration views.
  • Build your diagram incrementally by adding new types that have a relationship with a type already in the diagram. Select generalized, realized, associated and nested types from the context menu of a type or field to add them to the diagram. Or use to the familiar References context menu to find references to a class in the diagram.
  • When you update your source code, all open diagrams reflect the changes as soon as the source file is saved.
  • When you refactor your source code, all diagrams in the workspace are updated automatically (even if they are not open).
  • The Outline view shows all types in the diagram, along with their fields and methods. It also has a thumbnail of the diagram for easy navigation in large diagrams.
  • Save your diagram as a GIF, PNG or JPEG file so it can be incorporated into other documents.

A One-Minute Introduction

The ObjectAid UML Explorer has many more features than can be shown in a minute. All features are described in the online help that comes with the plug-in.

First you create an empty class diagram with the 'New' wizard. To get there, you can simply press Ctrl+N in the package or folder where you want to create your class diagram.

Then you drag some classes onto your diagram, typically from the Package Explorer. Any other view that contains Java types will work as well, e.g. the Type Hierarchy, Call Hierarchy and Search views.

Next you may want to add an associated class.

Since class PreferenceStore is too large, we adjusted its display options to hide fields and methods.
And now we look for references to Activator to see if we want any of them in the diagram.

The complete diagram might look like this: