Using IntelliJ IDEA Diagrams to Visualize Java Servlet Inheritance and Interface Relationships

The author, a software architect, shares a practical guide on using IntelliJ IDEA's diagram tool to visualize the inheritance chain of Java Servlet classes, making the previously confusing hierarchy easy to understand.

1. Viewing the inheritance diagram

Right‑click the class tab, choose Diagrams → Show (or the popup version) to open a graphical representation of the class hierarchy.

Images illustrate that the same action can be performed from the project tree.

2. Understanding diagram symbols

Blue solid arrows indicate inheritance, while green dashed arrows represent interface implementation.

3. Optimizing the diagram

Unwanted classes such as Object or Serializable can be removed by selecting them and pressing the Delete key, resulting in a cleaner view focused on the Servlet hierarchy.

4. Inspecting class details

Use Show Categories (or the toolbar button) to expand properties, methods, constructors, etc. Visibility can be filtered via Change Visibility Level to show only protected and higher members.

5. Zooming and navigation

Holding the Alt key activates a magnifier for better readability. The Structure tool window lists all members, allowing quick jumps to source code with Jump to Source .

6. Adding additional classes

Select Add Class to Diagram , type the desired class name, and it will appear in the same diagram, helping to discover relationships with other types.

7. Jumping to source code

Double‑click a class in the diagram, then right‑click a method and choose Jump to Source to open the actual code. The Structure view can also be used to navigate between members.

8. Conclusion

By combining these IDEA features, developers can efficiently study class relationships and explore framework source code, greatly improving learning and debugging productivity.