Install the correct JDK version

Use the following command to check your JDK version installed:

$ javac -version

For this project, it is recommended to use a long-term support (LTS) JDK version, either:

• Java JDK 8,
• Java JDK 11,
• Java JDK 17,
• Java JDK 21 or
• Java JDK 25

NOTES:

• JDK 24, JDK 23, JDK 22, JDK 20, JDK 19, JDK 18, JDK 16, JDK 15, JDK 14, JDK 13, JDK 12, JDK 10 and JDK 9 are deprecated versions, and although they may work with this project, it is not recommended to use them
• JDK 26, which will be available in March 2026 (but will be deprecated in September 2026), is not yet supported by Gradle, and therefore, it's not recommended to use

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Where do I download the JDK?

Download the free version of

• Azul Zulu OpenJDK 8,
• Azul Zulu OpenJDK 11,
• Azul Zulu OpenJDK 17,
• Azul Zulu OpenJDK 21 or
• Azul Zulu OpenJDK 25

from the Azul Zulu Builds of OpenJDK.

Scroll down until you see:

NOTE: Azul is a company that distributes Zulu, which is a certified binary build of OpenJDK.

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What if I want to download the official JDK from Oracle?

You can download Oracle JDK 21 without having to create an Oracle account.

You can download Oracle JDK 25 without having to create an Oracle account.

You can also download Oracle JDK 8, Oracle JDK 11 or Oracle JDK 17, but this requires the creation of a free Oracle account.