Common Errors Encountered in Scala and Solutions

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

1. Java Version Issue

   Unsupported major minor version

   https://stackoverflow.com/questions/22489398/unsupported-major-minor-version-52-0

java.lang.NoSuchMethodError: scala.Product.$init$¶

Fixing the Scala error: java.lang.NoSuchMethodError: scala.Product.$init$

It probably means This error is likely due to that you have a mismatch in the Scala versions you are using in your project. For example, I was using Scala 2.11 but mistakely specified Scala 2.12 for scala_xml for testing. It is suggested that you never hardcode Scala versions but instead define Scala versions (full version and compact version) in variables and use the version variables when specifying dependencies.

https://alvinalexander.com/misc/fixing-scala-error-java-lang.nosuchmethoderror-scala.product-init

Exception in thread “main” java.lang.NoClassDefFoundError: ...¶

This issue happens when you try to run the main function of a Scala object in IntelliJ IDEA. There are 2 possible causes. First, it might due to conflicting versions of Scala. If so, unify the version of Scala will resolve the issue. It is suggested that you never hardcode Scala versions but instead define Scala versions (full version and compact version) in variables and use the version variables when specifying dependencies. Second, it might due to the fact that Scala is specified as compileOnly dependency (Gradle). If so, specifying Scala as compile dependency resolves the issue.