Visualizing Java Servlet Inheritance Hierarchy with IntelliJ IDEA Diagrams

When you need to understand the inheritance chain of Java Servlet classes, IntelliJ IDEA's diagram tool provides a clear visual representation of both inheritance (solid blue arrows) and interface implementation (dashed green arrows).

Open the class file, right‑click in the editor tab, choose Diagrams → Show Diagram (or the popup version) to generate the diagram, which can also be accessed from the project tree.

To focus on relevant classes, select unwanted nodes in the diagram and press the Delete key; the cleaned‑up diagram will display only the important relationships.

For detailed class information, right‑click the diagram and select Show Categories (or use the toolbar) to expand fields, methods, constructors, and adjust visibility levels such as Change Visibility Level to filter by access modifiers.

You can enlarge the diagram by holding the Alt key, which activates a magnifier for better readability.

To add additional classes to the current diagram, right‑click the diagram background, choose Add Class to Diagram , and type the class name; the new class will appear with its own relationships (or none, if unrelated).

To view the actual source code of a method, double‑click the class in the diagram, then in the structure view select the method and choose Jump to Source . The Structure tool window can also list all methods for quick navigation.

Using these IDEA features makes exploring class hierarchies, understanding framework source code, and navigating between classes and methods much more efficient.