FULL PRODUCT VERSION :
java version "1.6.0_16"
Java(TM) SE Runtime Environment (build 1.6.0_16-b01)
Java HotSpot(TM) Client VM (build 14.2-b01, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]


A DESCRIPTION OF THE PROBLEM :
Due to the problem shown in bug 5069130 or similar, calling JEditorPane.setPage(URL) can lead to a RuntimeException caused by a NullPointerException. JEditorPane should handle the problem internally and rethrow as an IOException.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run code.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Expect an IOException to be thrown, caught, and ignored.
ACTUAL -
A RuntimeException (not a subclass of RuntimeException) is thrown.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
    Exception in thread "AWT-EventQueue-0" java.lang.RuntimeException: java.lang.NullPointerException
     at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1014)
     at sun.net.www.protocol.http.HttpURLConnection.getHeaderField(HttpURLConnection.java:2211)
     at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:382)
     at javax.swing.JEditorPane.getStream(JEditorPane.java:778)
     at javax.swing.JEditorPane.getStream(JEditorPane.java:792)
     at javax.swing.JEditorPane.setPage(JEditorPane.java:419)
     at javax.swing.JEditorPane.setPage(JEditorPane.java:923)
     at JEditorPaneBug7$1.run(JEditorPaneBug7.java:11)
     at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
     at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
     at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
     at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
     at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
     at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
    Caused by: java.lang.NullPointerException
     at sun.net.www.ParseUtil.toURI(ParseUtil.java:261)
     at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:795)
     at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:726)
     at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1049)
     at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:373)
     ... 13 more


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import javax.swing.*;

public class JEditorPaneBug7 {
  public static void main(String args[]) {
    SwingUtilities.invokeLater(
      new Runnable() {
        public void run() {
          JEditorPane jep = new JEditorPane();
               
          try {
             // Same URL from bug 5069130.
             jep.setPage("http://www.scielo.br/gmb.htm");
          }
          catch(java.io.IOException e) {
          }
        }
      });
  }
}

---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Catch the exception, examine it to be sure it is this problem, ignore it if it is, otherwise rethrow.