This was reported by Arjun at my blog:
http://hirt.se/blog/?p=854

<-- -->
Marcus, Just an FYI…
I got the JMC/Joverflow add-in onto eclipse. I could analyze smaller heap.hprof dumps (less than a 1gig) without any issues, but when i tried it on a 3gig dump it threw the below error, the same 3 gig file opened in eclipse MAT and Java Visual VM ( bumped the -Xmx to 4 gig -Xmx4g). Its just that I like the layout of JOverflow and I wish we could open larger heap files.

com.oracle.joverflow.heap.parser.DumpCorruptedException: exception caught: java.io.IOException: Stream Closed
at com.oracle.joverflow.heap.parser.DumpCorruptedException$Runtime.(DumpCorruptedException.java:29)
at com.oracle.joverflow.heap.model.JavaValueArray.readValue(JavaValueArray.java:107)
at com.oracle.joverflow.heap.model.HeapStringReader.readCharElements(HeapStringReader.java:87)
at com.oracle.joverflow.heap.model.HeapStringReader.readString(HeapStringReader.java:48)
at com.oracle.joverflow.stats.StringStatsCollector.add(StringStatsCollector.java:84)
at com.oracle.joverflow.stats.OverallStatsCalculator.calculate(OverallStatsCalculator.java:98)
at com.oracle.joverflow.stats.StandardStatsCalculator.calculate(StandardStatsCalculator.java:43)
at com.oracle.joverflow.ui.model.ModelLoader.run(ModelLoader.java:85)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
cheers
Arjun

<-- -->