ClassCastException when querying an entry set w/ Comparator

Question

Hi,
I have come across a problem trying to retrieve a sorted entry set from a distributed cache. I have a cache containing objects of a single class (OrderHistory) and am using the NamedCache.entrySet(filter, comparator) method. The results are fine when only a filter is used, and also when 'null' is passed as the comparator (correctly sorting OrderHistories in natural order). However, a ClassCastException occurs when I specify my own OrderSorter as a comparator. This occurs even when the OrderSorter class is stripped of all mention of the OrderHistory class and the compare method is reduced to:
     public int compare(Object o1, Object o2) {
          return 1;
OrderSorted implements both Comparator and ExternalizableLite. It appears that Tangosol is attempting to perform the cast internally. The stack trace is as follows:
Failed request execution for DistributedCache service on Member(Id=1, Timestamp=2007-05-14 15:19:34.9, Address=10.142.194.36:8088, MachineId=17956))
java.lang.ClassCastException: com.[...].OrderHistory
     at com.tangosol.util.comparator.EntryComparator.compare(EntryComparator.java:103)
     at com.tangosol.util.comparator.SafeComparator.compareEntries(SafeComparator.java:106)
     at com.tangosol.util.comparator.EntryComparator.compare(EntryComparator.java:114)
     at java.util.Arrays.mergeSort(Arrays.java:1284)
     at java.util.Arrays.sort(Arrays.java:1223)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.DistributedCache$Storage.extractBinaryEntries(DistributedCache.CDB:9)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.DistributedCache$Storage.query(DistributedCache.CDB:209)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.DistributedCache.onQueryRequest(DistributedCache.CDB:23)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.DistributedCache$QueryRequest.run(DistributedCache.CDB:1)
     at com.tangosol.coherence.component.net.message.requestMessage.DistributedCacheRequest.onReceived(DistributedCacheRequest.CDB:12)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.Service.onMessage(Service.CDB:9)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.Service.onNotify(Service.CDB:122)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.DistributedCache.onNotify(DistributedCache.CDB:3)
     at com.tangosol.coherence.component.util.Daemon.run(Daemon.CDB:35)
     at java.lang.Thread.run(Thread.java:595)
Any ideas?
Thanks in advance,
James

Answer 1

Err, seems that bug is not fixed yet, at least version 3.5/459 still has it. Too bad.
Here is my test case & stack trace:
log("building cache instance");
NamedCache cache = CacheFactory.getCache("mycache");
log("put some objects into the cache");
cache.put("#TEST#10#001","#1111");
cache.put("#TEST#10#012","#2222");
cache.put("#TEST#10#003","#3333");
cache.put("#TEST#20#1","#4444");
log("building filter object");
Filter filter = new LikeFilter(new KeyExtractor(), "#TEST#10%",'\\',true);
testComparator comparator = new testComparator();
for (Iterator it = cache.entrySet(filter,new EntryComparator(comparator, EntryComparator.CMP_KEY)).iterator(); it.hasNext();) {
Map.Entry curr_entry = (Map.Entry)it.next();
System.out.println("curr_key="+curr_entry.getKey().toString()+
"curr_value="+curr_entry.getValue().toString()
Exception in thread "main" java.lang.ClassCastException: java.lang.String
     at com.tangosol.util.comparator.EntryComparator.compare(EntryComparator.java:99)
     at com.tangosol.util.comparator.SafeComparator.compareSafe(SafeComparator.java:166)
     at com.tangosol.util.comparator.SafeComparator.compare(SafeComparator.java:84)
     at com.tangosol.util.comparator.EntryComparator.compare(EntryComparator.java:115)
     at java.util.Arrays.mergeSort(Arrays.java:1284)
     at java.util.Arrays.sort(Arrays.java:1223)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.DistributedCache$ViewMap.entrySet(DistributedCache.CDB:105)
     at com.tangosol.coherence.component.util.SafeNamedCache.entrySet(SafeNamedCache.CDB:1)
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