[WICKET-1065] NullPointer in FileCleaner causes infinite loop

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.3.0-beta4
• Fix Version/s: 1.3.0-rc1
• Component/s: wicket
• Environment: OpenSuse 10.3, Java 1.6.0 update 3, Apache Tomcat 5.5.25, Eclipse 3.3.0
• Assignee: Juegen Donnerstag
• Reporter: Geir Ove Grønmo
• Created: 12/Oct/07 10:08
• Updated: 14/Oct/07 08:03
• Resolved: 14/Oct/07 08:03

Description

While hot deploying a Wicket application from Eclipse to a Tomcat instance the "File Reaper" thread seems to go into an infinite loop making the CPU running at 100%. From the thread dump it is clear that a NullPointerException is being thrown on line 61 in FileCleaner.java. Looking at the source code reveals that the ReferenceQueue q member in FileCleaner is null.

"File Reaper" daemon prio=10 tid=0x08265c00 nid=0x18cf runnable [0x9a2d9000..0x9a2d9f30]
java.lang.Thread.State: RUNNABLE
at java.lang.Throwable.fillInStackTrace(Native Method)

• locked <0x701b0000> (a java.lang.NullPointerException)
  at java.lang.Throwable.<init>(Throwable.java:181)
  at java.lang.Exception.<init>(Exception.java:29)
  at java.lang.RuntimeException.<init>(RuntimeException.java:32)
  at java.lang.NullPointerException.<init>(NullPointerException.java:36)
  at org.apache.wicket.util.file.FileCleaner$1.run(FileCleaner.java:61)