In the below function, the line marked yellow is giving com.thoughtworks.xstream.alias.CannotResolveClassException. the variable xml contains the correct bean in string format but conversion fails here.
public List<DocumentPermissionBean> getDocumentPermissionsFromCache(Document document) {

String docPermissionBeantring = (String) DocBuilderCacheFactory.getCache(
DocBuilderCacheType.PERMISSION_ID).get(document.getId());
if (docPermissionBeantring == null) {
return null;
}
List<Long> docPermissionBeanList = (List<Long>) xstream.fromXML(docPermissionBeantring);

for (Long docPermissionBean : docPermissionBeanList) {
String xml = (String) DocBuilderCacheFactory.getCache(
DocBuilderCacheType.PERMISSION_BEANS).get(docPermissionBean);

if (xml == null) {
return null;
}
cachedDocPermissionBean = (DocumentPermissionBean) xstream.fromXML(xml);

cachedDocPermissionBeans.add(cachedDocPermissionBean);
}
return cachedDocPermissionBeans;
}

The value of variable "xml" when I debug the code and the error stack (not complete) is documented below. The conversion is failing at the line marked blue.


Variable xml Value:

<com.abc.xyz.docbuilder.database.beans.DocumentPermissionBean>
<permissionId>3</permissionId>
<documentBean>
<documentId>1</documentId>
<documentName>ewr</documentName>
<documentAuthor>admin</documentAuthor>
<documentDescription>wer</documentDescription>
<lastModifier>admin</lastModifier>
<creationDate class="sql-timestamp">2011-07-20 11:57:29.056</creationDate>
<currentVersion>1</currentVersion>
<currentVersionDate class="sql-timestamp">2011-07-20 11:57:29.056</currentVersionDate>
<contentBeans class="net.sf.hibernate.collection.Set">
<set>
<com.abc.xyz.docbuilder.database.beans.DocumentContentBean>
<id>2</id>
<documentBean reference="../../../.."/>
<pageId>32785</pageId>
<pageOrder>1</pageOrder>
</com.abc.xyz.docbuilder.database.beans.DocumentContentBean>
<com.abc.xyz.docbuilder.database.beans.DocumentContentBean>
<id>1</id>
<documentBean reference="../../../.."/>
<pageId>32780</pageId>
<pageOrder>2</pageOrder>
</com.abc.xyz.docbuilder.database.beans.DocumentContentBean>
</set>
<initialized>true</initialized>
<collectionSnapshot class="net.sf.hibernate.impl.SessionImpl-CollectionEntry">
<dirty>false</dirty>
<initialized>true</initialized>
<loadedKey class="long">1</loadedKey>
<snapshot class="map">
<entry>
<com.abc.xyz.docbuilder.database.beans.DocumentContentBean reference="../../../../set/com.abc.xyz.docbuilder.database.beans.DocumentContentBean"/>
<com.abc.xyz.docbuilder.database.beans.DocumentContentBean reference="../../../../set/com.abc.xyz.docbuilder.database.beans.DocumentContentBean"/>
</entry>
<entry>
<com.abc.xyz.docbuilder.database.beans.DocumentContentBean reference="../../../../set/com.abc.xyz.docbuilder.database.beans.DocumentContentBean[2]"/>
<com.abc.xyz.docbuilder.database.beans.DocumentContentBean reference="../../../../set/com.abc.xyz.docbuilder.database.beans.DocumentContentBean[2]"/>
</entry>
</snapshot>
<role>com.abc.xyz.docbuilder.database.beans.DocumentBean.contentBeans</role>
</collectionSnapshot>
</contentBeans>
</documentBean>
<entityName>admin</entityName>
<entityType>USER</entityType>
<permissionName>UPDATE</permissionName>
<permissionValue>true</permissionValue>
</com.abc.xyz.docbuilder.database.beans.DocumentPermissionBean>


Error Stack:
[INFO] [talledLocalContainer] ---- Debugging information ----
[INFO] [talledLocalContainer] message : net.sf.hibernate.impl.SessionImpl$CollectionEntry : net.sf.hibernate.impl.SessionImpl$CollectionEn
try
[INFO] [talledLocalContainer] line number : 28
[INFO] [talledLocalContainer] path : /com.abc.xyz.docbuilder.database.beans.DocumentPermissionBean/documentBean/contentBeans/colle
ctionSnapshot
[INFO] [talledLocalContainer] cause-message : net.sf.hibernate.impl.SessionImpl$CollectionEntry : net.sf.hibernate.impl.SessionImpl$CollectionEn
try
[INFO] [talledLocalContainer] class : com.abc.xyz.docbuilder.database.beans.DocumentPermissionBean
[INFO] [talledLocalContainer] cause-exception : com.thoughtworks.xstream.alias.CannotResolveClassException
[INFO] [talledLocalContainer] required-type : net.sf.hibernate.collection.Set
[INFO] [talledLocalContainer] -------------------------------
[INFO] [talledLocalContainer] atlassian.core.seraph.original.url: /plugins/docbuilder/permissioninfo.action
[INFO] [talledLocalContainer] javax.servlet.error.status_code: 500
[INFO] [talledLocalContainer] javax.servlet.error.servlet_name: action
[INFO] [talledLocalContainer] __sitemesh__using_stream: false
[INFO] [talledLocalContainer] com.atlassian.gzipfilter.GzipFilter_already_filtered: true
[INFO] [talledLocalContainer] loginfilter.already.filtered: true
[INFO] [talledLocalContainer] com.atlassian.confluence.web.ConfluenceJohnsonFilter_already_filtered: true
[INFO] [talledLocalContainer] Confluence-Request-Time: 1311260585587
[INFO] [talledLocalContainer] javax.servlet.error.message:
[INFO] [talledLocalContainer] com.atlassian.core.filters.HeaderSanitisingFilter_already_filtered: true
[INFO] [talledLocalContainer] webwork.valueStack: com.opensymphony.xwork.util.OgnlValueStack@1365dd2
[INFO] [talledLocalContainer] sessioninview.FILTERED: true
[INFO] [talledLocalContainer] __sitemesh__filterapplied: true
[INFO] [talledLocalContainer] javax.servlet.error.exception: com.thoughtworks.xstream.converters.ConversionException: net.sf.hibernate.impl.SessionImp
l$CollectionEntry : net.sf.hibernate.impl.SessionImpl$CollectionEntry
[INFO] [talledLocalContainer] ---- Debugging information ----
[INFO] [talledLocalContainer] message : net.sf.hibernate.impl.SessionImpl$CollectionEntry : net.sf.hibernate.impl.SessionImpl$CollectionEn
try
[INFO] [talledLocalContainer] line number : 28
[INFO] [talledLocalContainer] path : /com.abc.xyz.docbuilder.database.beans.DocumentPermissionBean/documentBean/contentBeans/colle
ctionSnapshot
[INFO] [talledLocalContainer] cause-message : net.sf.hibernate.impl.SessionImpl$CollectionEntry : net.sf.hibernate.impl.SessionImpl$CollectionEn
try
[INFO] [talledLocalContainer] class : com.abc.xyz.docbuilder.database.beans.DocumentPermissionBean
[INFO] [talledLocalContainer] cause-exception : com.thoughtworks.xstream.alias.CannotResolveClassException
[INFO] [talledLocalContainer] required-type : net.sf.hibernate.collection.Set
[INFO] [talledLocalContainer] -------------------------------
[INFO] [talledLocalContainer] javax.servlet.error.request_uri: /confluence/plugins/docbuilder/permissioninfo.action
[INFO] [talledLocalContainer] --------------------------
[INFO] [talledLocalContainer] Parameters
[INFO] [talledLocalContainer] --------------------------
[INFO] [talledLocalContainer] documentId : 1
[INFO] [talledLocalContainer] caused by: com.thoughtworks.xstream.converters.ConversionException: net.sf.hibernate.impl.SessionImpl$CollectionEntry :
net.sf.hibernate.impl.SessionImpl$CollectionEntry
[INFO] [talledLocalContainer] ---- Debugging information ----
[INFO] [talledLocalContainer] message : net.sf.hibernate.impl.SessionImpl$CollectionEntry : net.sf.hibernate.impl.SessionImpl$CollectionEntry
[INFO] [talledLocalContainer] line number : 28
[INFO] [talledLocalContainer] path : /com.abc.xyz.docbuilder.database.beans.DocumentPermissionBean/documentBean/contentBeans/colle
ctionSnapshot
[INFO] [talledLocalContainer] cause-message : net.sf.hibernate.impl.SessionImpl$CollectionEntry : net.sf.hibernate.impl.SessionImpl$CollectionEn
try
[INFO] [talledLocalContainer] class : com.abc.xyz.docbuilder.database.beans.DocumentPermissionBean
[INFO] [talledLocalContainer] cause-exception : com.thoughtworks.xstream.alias.CannotResolveClassException
[INFO] [talledLocalContainer] required-type : net.sf.hibernate.collection.Set
[INFO] [talledLocalContainer] -------------------------------
[INFO] [talledLocalContainer] at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:45)
[INFO] [talledLocalContainer] caused by: com.thoughtworks.xstream.alias.CannotResolveClassException: net.sf.hibernate.impl.SessionImpl$CollectionEntry
: net.sf.hibernate.impl.SessionImpl$CollectionEntry
[INFO] [talledLocalContainer] at com.thoughtworks.xstream.mapper.DefaultMapper.realClass(DefaultMapper.java:35)
[INFO] [talledLocalContainer]

Can anyone suggest what might be the reason for the error here?

Thanks!