Why / How does IntelliJ trigger debug output in Netbeans?

Question

Yesterday I debugged a Java application with Netbeans. (i.e. the application worked with the attached debugger). At the same time, I was working with IntelliJ in a Rails application.

I noticed two unusual messages in the Netbeans debug output window:

Exception "java.lang.ClassNotFoundException: com.intellij.codeInsight.editorActions.FoldingTransferableData$FoldingData" while constructing DataFlavor for: application/x-java-jvm-local-objectref; class=com.intellij.codeInsight.editorActions.FoldingTransferableData$FoldingData 

and

 Exception "java.lang.ClassNotFoundException: com.intellij.codeInsight.editorActions.ReferenceTransferableData$ReferenceData" while constructing DataFlavor for: application/x-java-jvm-local-objectref; class=com.intellij.codeInsight.editorActions.ReferenceTransferableData$ReferenceData 

Just out of curiosity: What is going on here?

If that matters: I am using Netbeans 7.0.1 and IntelliJ 10.5.2 (Evaluation) with the Ruby plugin.

Answer 1

This is not an IDEA causing any output, but Netbeans. Netbeans is trying to parse the contents of the clipboard containing the serialized Java object that IDEA placed there. Since Netbeans is not aware of any IntelliJ IDEA classes, it prints this error.

Answer 2

This is a serialized object placed on the IntelliJ clipboard (Transferable for clipboard operations), which is unknown to Netbeans. Do not worry about anything.