I noticed this with rc2, and meant to submit this
bug, but didn't do it soon enough.

When attempting to expand a source package which
had annotations testing classes in it, I noticed
the folder was empty. It took a while to figure
out the offending class as FolderChildren just
chokes and dies when creating nodes. Anyhoo, heres
the source of the class file (like I said, it was
a test):


import java.lang.annotation.*;
import java.lang.reflect.*;
import java.util.*;

@Retention(RetentionPolicy.RUNTIME)
@interface Test {
    String value();
}

@Test("Hello") public class AnnotationTest {
    
    @Test("Method") public static void
main(@Test("argument") String[] args) {
        System.out.println(AnnotationTest.class);
        
        for (Annotation ann :
AnnotationTest.class.getAnnotations()) {
            System.out.println("Class :" + ann);
        }
    }
}


To (hopefully) duplicate this, stick this in a
project source directory and use the command line
to compile it. Now reresh the folder. If that
fails, close the project and reopen it and attempt
to open the folder again.

For both ide sanity and my own (I also make
modules) it'd be nice if FolderChildren was
friendlier with logging which of its children
caused a problem. In this case, I wrote a shell
script which removed each class one by one,
pausing long enough for me to hit the refresh
button on the folder.

Heres that stack trace:
java.lang.NullPointerException
        at
org.netbeans.modules.clazz.SourceElementImpl.initializeData(SourceElementImpl.java:108)
        at
org.netbeans.modules.clazz.SourceElementImpl.attachedToElement(SourceElementImpl.java:91)
        at
org.openide.src.Element.<init>(Element.java:54)
        at
org.openide.src.SourceElement.<init>(SourceElement.java:49)
        at
org.netbeans.modules.clazz.ClassDataObject.getSource(ClassDataObject.java:174)
        at
org.netbeans.modules.clazz.ClassDataNode.initialize(ClassDataNode.java:96)
        at
org.netbeans.modules.clazz.ClassDataNode.<init>(ClassDataNode.java:76)
        at
org.netbeans.modules.clazz.ClassDataNode.<init>(ClassDataNode.java:71)
        at
org.netbeans.modules.clazz.CompiledDataNode.<init>(CompiledDataNode.java:57)
        at
org.netbeans.modules.clazz.CompiledDataObject.createNodeDelegate(CompiledDataObject.java:107)
        at
org.openide.loaders.DataObject$1.run(DataObject.java:249)
        at
org.openide.util.Mutex.readAccess(Mutex.java:246)
        at
org.openide.loaders.DataObject.getNodeDelegate(DataObject.java:245)
        at
org.openide.loaders.DataObject.getClonedNodeDelegate(DataObject.java:270)
        at
org.openide.loaders.FolderChildren.createNodes(FolderChildren.java:143)
        at
org.openide.nodes.Children$Keys$KE.nodes(Children.java:2028)
        at
org.openide.nodes.ChildrenArray.nodesFor(ChildrenArray.java:112)
        at
org.openide.nodes.Children$Info.nodes(Children.java:1125)
        at
org.openide.nodes.Children.updateAdd(Children.java:933)
        at
org.openide.nodes.Children.setEntries(Children.java:720)
        at
org.openide.nodes.Children$5.run(Children.java:1919)
        at
org.openide.util.Mutex.postRequest(Mutex.java:987)
        at
org.openide.util.Mutex.postWriteRequest(Mutex.java:438)
        at
org.openide.nodes.Children$Keys.applyKeys(Children.java:1927)
        at
org.openide.nodes.Children$Keys.setKeys(Children.java:1886)
        at
org.openide.loaders.FolderChildren.access$500(FolderChildren.java:33)
        at
org.openide.loaders.FolderChildren$ChildrenRefreshRunnable.run(FolderChildren.java:251)
        at org.openide.util.Task.run(Task.java:136)
        at
org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:330)
[catch] at
org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:686)