Issue with Could not initialize class $linec4a1686037264c21b0e58b369fab8f2d59.$read$

[williamwjs]

Our job is written in Scala on DataBricks. It used to have the same problem, but was managed to work with putting all case classes in a separate cell. However, lately it started to fail again due to the same error:

Could not initialize class $linec4a1686037264c21b0e58b369fab8f2d59.$read$
Caused by: NoClassDefFoundError: Could not initialize class $linec4a1686037264c21b0e58b369fab8f2d59.$read$

May I ask if you could help suggest a solution to this?
Thank you!

[Kaniz]

Hi @williamwjs, Certainly! The error message you’re encountering, NoClassDefFoundError, indicates that a class could not be initialized.

Let’s explore some potential solutions:

Scala Version Compatibility:

• Ensure that the Scala version used in your Databricks environment matches the version of the library you’re using. If there’s a mismatch, it can lead to class initialization issues.
• For Databricks Runtime (DBR) versions earlier than 7.0, use Scala 2.11-compatible libraries. For DBR 7.0 and later, use Scala 2.12-compatible libraries.

Dependency Resolution:

• Confirm that the necessary libraries are available in your cluster’s runtime environment. You can explicitly add dependencies using the %AddJar magic command.

Serialization and Object Initialization:

• If you’re using an object (singleton) that fails to initialize, consider converting it to a class that extends Serializable. Instantiate the class where needed.
• For example, if you have an object named test with a method foo, create a class Test that extends Se....

Check for Logging Dependencies:

• Sometimes issues related to logging libraries can cause class initialization problems. Ensure that any logging dependencies are correctly configured.

Remember to check the Scala version, verify dependencies, and consider serialization when troubleshooting this issue.

If you provide more details about your specific setup, I can offer more targeted advice! 🚀

[Kaniz]

Thank you for posting your question in our community! We are happy to assist you.

To help us provide you with the most accurate information, could you please take a moment to review the responses and select the one that best answers your question?

This will also help other community members who may have similar questions in the future. Thank you for your participation and let us know if you need any further assistance! 
 

[williamwjs]

Hi @Kaniz  , these do not help for my case.

Since the class that is not found is the `case class` I created in code, so it is not an issue with the dependencies. And adding `extends Serializable` does not help either.

Could you help suggest again?
Thank you!

[Kaniz]

Hi @williamwjs, 

Classpath Configuration:

• In Eclipse, go to Run -> Run Configurations….
• Select the unit test’s run configuration and click on the Classpath tab.
• Check Use temporary JAR to specify….
• Under User Entries, move Maven Dependencies above your project or test class.
• Click the Run button to execute your JUnit test.

Maven Dependency Scope:

• Ensure that the Maven dependency for your custom case class is correctly configured. If you expect the JDK or a container to provide the dependency at runtime, set the dependency scope ....

Check for Deprecated Classes:

• Sometimes deprecated classes can cause issues. Make sure you’re not using any deprecated classes or methods in your code.

[williamwjs]

Hi @Kaniz , may I ask if there's any updates to this issue? Thank you!