java - Why/How is IntelliJ causing debug output in Netbeans?

Question

Yesterday I was debugging a Java application with Netbeans. (i.e. the application was running with the debugger attached) At the same time I was working with IntelliJ on a Rails application.

I noticed two strange 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 was happening here?

If it matters: I'm using Netbeans 7.0.1 and IntelliJ 10.5.2 (Evaluation) with the Ruby plugin.

Answer 1

This is not IDEA causing any output but Netbeans. Netbeans is trying to analyze the contents of the clipboard which contains a serialized Java object that has been put there by IDEA. Since Netbeans does not know about any IntelliJ IDEA classes, it prints this error.