Second XMLEncoder Silently Dies On Shared Stream?

My adventures with XMLEncoder continue...

I've got a simple main routine that instantiates two structurally identical classes, and attempts to write them both out to System.out with an XMLEncoder:

package xmlencoding;
import java.beans.XMLEncoder;
public class Twice {
public String name;
public static void main(String[] args)

[code]....

I expected Line 16 and Line 24 to both write some XML-formatted output, looking very similar to each other. But here's my output:

<?xml version="1.0" encoding="UTF-8"?>
<java version="1.8.0_05" class="java.beans.XMLDecoder">
<object class="xmlencoding.Twice$C1" id="Twice$C10">
<void class="xmlencoding.Twice$C1" method="getField">
<string>him</string>

[Code] ....

Now, if I change Line 24 so that the second call to writeObject is to a different stream("23. XMLEncoder e2 = new XMLEncoder(System.err);"), I do get both outputs:

<?xml version="1.0" encoding="UTF-8"?>
<java version="1.8.0_05" class="java.beans.XMLDecoder">
<object class="xmlencoding.Twice$C1" id="Twice$C10">
<void class="xmlencoding.Twice$C1" method="getField">
<string>him</string>

[code]....

So, I am inferring that this means two XMLEncoder objects can't both hold references to the same OutputStream, even if the first object is closed before the second is created. In actual practice, I guess I can live with that, since I wouldn't write the XML-encoded version of two objects to the same stream (I'd get the header twice in the same file, and I believe that's a no-no). But I am surprised that this doesn't generate some kind of exception, either when the second XMLEncoder is constructed, or when its writeObject method is called. But, it just silently dies.