README_SCALA_CONFIG.md

Setup for working scala configuration

Prerequisites:

installed packages in following versions:

• JDK 21

  • https://www.oracle.com/java/technologies/downloads/

• SBT

  • https://www.scala-sbt.org/download.html

• Scala

  • https://www.scala-lang.org/download/

• IntelliJ IDEA

  • https://www.jetbrains.com/idea/download/

Scala can be directly downloaded and installed trough the IDEA by Creating Scala Project:

• Open up IntelliJ and click File => New => Project
• On the left panel, select Scala. On the right panel, select IDEA.
• Name the project e.g. ToDelete
• To the right of the Scala SDK field, click the Create button. Select the highest version number and click Download. This might take a few minutes but subsequent projects can use the same SDK. Once the SDK is created and you’re back to the “New Project” window click Finish or discard whole project.

Importing the project from git to IDEA

• Open IDEA

• Select File > New > Project from existing sources

• Locate folder "exercises-homework": under NPRG014\lecture-scala\exercises-homework

• Select Import project from external model

  • and select "sbt"
  • In next window keep defaults (Only selected item is Download Library sources)




Confirm that hello world under ./src/main/scala/e01 works. (select file in the tree and click Run HelloWorld (Ctrl+Shift+F10))

If that works, your IDEA is configured properly.

Dealing with common errors

Try the import again with different settings

In case this setup does not work try to trigger selectors during the import project in sections "Download" and use "sbt shell" as seen in the previous picture

dump project structure fails with null pointer exception

Edit file "./project/build.properties" to contain "sbt.version = 1.10.0" (or current latest version this is mainly for future reference since the file has already been changed to contain this version)

Many missing classes

To fix errors like: "Error could not find or load main class e01.HelloWorld" in Run/Debug configuration under Use classpath or module choose "NPRG014 Scala"