When I using Netbeans 6 (final released) and using Apache Common Configuration library, I encounter this bug.
Here’s how I found the bug :

• Create a java application project
• Add the library, I create a library name ‘Apache_Common_Configuration’ and add commons-configuration-1.5.jar to that library
• Then I wrote the code

public static void main(String[] args) {
try {
INIConfiguration ini = new INIConfiguration("sample.ini");
} catch (ConfigurationException ex) {
ex.printStackTrace();
}
}


• But the editor showing error on ‘ConfigurationException ex’ saying that ConfigurationException is not subclass of Throwable Class (I’ve upload the screenshot)

• When I try to build it’s showing different error “class file for org.apache.commons.lang.exception.NestableException not found”
• It’s look like Apache Common Configuration is using Apache Common Lang library (I also look to the source-code ‘ConfigurationException extends NestableException’). Error when compile showing me more help than error in editor.
• So I create a library name ‘Apache_Common_Lang’ and add commons-lang-2.3.jar to that library
• After add the library the editor still showing the same error : “ConfigurationException is not subclass of Throwable Class”
• But when I run build, it run successful . No error at all. (Now I confused)
• It’s look like there’s a bug in the Editor. And that red line & error icon in project window really bugging me, although I know it’s the editor bug not my code error.
• So to make this ‘red-line’ disappeared, I combined commons-configuration-1.5.jar & commons-lang-2.3.jar into 1 jar file. And set a library to this jar (instead using 2 library or 2 jar file).
• After this combined the editor not showing the error again.

Anyone having this problem too?

You can vote for this bug on : http://www.netbeans.org/issues/show_bug.cgi?id=124241

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