ConcurrentModificationException

[mschipperheyn]

Hi,

I'm storing FacetHandlers in a local cache for reuse across requests. Also, I'm storing the BoboIndexReader in a cache that I temporarily refresh.

I'm sometimes seeing 

[code]

java.util.ConcurrentModificationException

        at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)

        at java.util.AbstractList$Itr.next(AbstractList.java:343)

[/code]

occur in the log when I'm looping over a list of facethandlers I retrieved from the cache. This doesn't happen often. I'm just wondering when this might occur and how to avoid this?

[code]

for (FacetHandler<?> fh : handlerList) {//BOOM

[...]

}

[/code]

Could this be a problem related to the refreshing of the BoboIndexReader?

My code for this is 

[code]

@Override

public void refreshBoboIndexReader(Class<?> clazz, boolean reopen) {

try {

if (reopen) {

setBoboIndexReader(clazz, getBoboReader(clazz));

}

} catch (IOException io) {

log.error("Error creating indexReader", io);

}

}

protected void setBoboIndexReader(Class<?> clazz, BoboIndexReader breader)

throws IOException {

MyDaoHibernate.writeLock.lock();

try {

if (boboReaders.containsKey(clazz))

boboReaders.get(clazz).close();

boboReaders.put(clazz, breader);

} finally {

MyDaoHibernate.writeLock.unlock();

}

}

protected BoboIndexReader getBoboReader(final Class<?> clazz)

throws IOException {

TransactionTemplate transTemplate = new TransactionTemplate(

transactionManager);

IndexReader i = transTemplate

.execute(new TransactionCallback<IndexReader>() {

@Override

public IndexReader doInTransaction(

TransactionStatus status) {

FullTextSession fts = Search

.getFullTextSession(getSessionFactory()

.getCurrentSession());

MutableSearchFactory factory = (MutableSearchFactory) fts.getSearchFactory();

DirectoryBasedIndexManager mgr = (DirectoryBasedIndexManager) factory.getAllIndexesManager().getIndexManager(clazz.getCanonicalName());

try{

return IndexReader.open(mgr.getDirectoryProvider().getDirectory(), true);

}catch(IOException io){

log.error("Error opening indexreader for Bobo", io);

}

return null;

}

});

return BoboIndexReader.getInstance(

i,

sfFactory.getUnfilteredList(), null);

}

[/code]

Kind regards,

Marc

[mschipperheyn]

Anyone? This is pretty serious for me and I'm seeing it more often
now.

[mschipperheyn]

HELP!

[mschipperheyn]

Ok, fixed. This didn't have anything to do with Bobo. I was adding a
facethandler to a cached list of facethandlers conditionally. This
generated the concurrentmod exception