Mastering IntelliJ IDEA Diagrams to Visualize Java Servlet Inheritance

When revisiting Java Servlet knowledge, the author found IntelliJ IDEA's diagram tool extremely helpful for visualizing class inheritance and interface implementation relationships.

1. Viewing Inheritance Diagrams

Right‑click a class tab and choose Diagrams → Show (embedded) or Show ... Popup (floating). The same option is available from the project tree.

The resulting diagram displays inheritance with solid blue arrows and interface implementation with dashed green arrows.

2. Optimizing the Diagram

2.1 Removing Unwanted Classes

Select unnecessary classes (e.g., Object, Serializable) and press Delete to clean the view.

2.2 Showing Class Details

Right‑click the diagram and select Show Categories to expand attributes, methods, constructors, etc., or use the toolbar. Visibility can be filtered (e.g., show only protected members) via Change Visibility Level .

2.3 Zooming

Press Alt to activate a magnifier for better readability.

2.4 Adding Other Classes

Use Add Class to Diagram , type the class name, and it will appear in the diagram. If no arrows connect, the class has no direct inheritance or interface relationship with the existing nodes.

2.5 Viewing Source Code

Double‑click a class in the diagram, then right‑click a method and choose Jump to Source to open the code. The Structure tool window lists all members for quick navigation.

3. Conclusion

Using IntelliJ IDEA’s diagram, show, filter, and navigate class relationships makes studying frameworks and source code much more comfortable.