The following is available only in the Ultimate edition of IntelliJ IDEA

UML modeling support provided by IntelliJ IDEA involves two aspects:

UML model in IntelliJ IDEA is represented by a Class diagram in standard notation.

IntelliJ IDEA enables using UML class diagrams to analyze  Java, JavaScript, ActionScript/Flex, PHP, and Maven applications,  and the structure of the databases and tables. Besides that, you can explore changes committed to VCS.

In IntelliJ IDEA, Class diagram features:

See Also

Concepts:

Reference:

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