Java 17

Get up to speed on Java 17 with our top tips.

2022-05-22

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IntelliJ IDEA always supports the most recent version of Java. If you want to see the new features that are most interesting to Java developers, and see how IntelliJ IDEA helps us to use these features, these tips are a great place to start.

IntelliJ IDEA's Inspections will show you how to the new Java 17 functionality such as Sealed Classes and Pattern Matching for switch.

Create a correct child Sealed Class

Sealed types are a new idea for Java developers, let IntelliJ IDEA guide you in how to create child classes

Sealed classes (first preview feature in Java 16) are a way to take control of the inheritance hierarchy of our classes. IntelliJ IDEA can let us know about problems in the classes that extend sealed classes, and suggest solutions.

Experiment with Sealed Types, use Alt+Enter (Windows/Linux) to see and accept suggestions.

Create a correct parent Sealed Class

Sealed types are a new idea for Java developers, let IntelliJ IDEA guide you in how to use them

Sealed classes (a preview feature in Java 16) are a way to take control of the inheritance hierarchy of our classes. If we have a sealed class like this one, IntelliJ IDEA will tell us we need to "permit" the child class so it can extend this parent. It will also automatically make changes if it can.

Experiment with Sealed Types, use Alt+Enter (Windows/Linux) to see and accept suggestions.

Pattern Matching for Switch

Available in preview from Java 17

Ensure your SDK and Language Level are at least Java 17 (Preview) in your Project Structure with ⌘; (macOS) / Ctrl+Alt+Shift+S (Windows/Linux).

IntelliJ IDEA highlights code that can be replaced with a switch expression using pattern variables. Press ⌥⏎ (macOS) / Alt+Enter (Windows/Linux) and choose "Replace if with switch".