Concurrent Modification Exception

rberg — Tue, 21 Feb 2006 16:14:47 GMT

Hello,I have been getting this error a lot lately, and it leads me to believe that I am not properly using transactions:09:48:57,825 ERROR [org.alfresco.web.ui.common.Utils] Unable to check out Content Node due to system error:nulljava.util.ConcurrentModificationException at java.util.HashMap$Hash

Re: Concurrent Modification Exception

rberg — Tue, 21 Feb 2006 19:44:13 GMT

Update:

I was able to avoid this error by implementing TransactionListener. The source is as follows:


public class AuditTrailAspect implements TransactionListener, ContentServicePolicies.OnContentReadPolicy, ContentServicePolicies.OnContentUpdatePolicy
{
   // Members
   private AuthenticationService authenticationService;
    private PolicyComponent policyComponent;
   private AuditTrailService auditTrailService;
    private static final String AUDIT_TRAIL_ITEMS = "AuditTrailAspect.auditTrailItems";

    public void init()
    {
        this.policyComponent.bindClassBehaviour(
                                 ContentServicePolicies.ON_CONTENT_READ,
                                 ContentModel.ASPECT_AUDITTRAIL,
                                 new JavaBehaviour(this, "onContentRead"));

        this.policyComponent.bindClassBehaviour(
                                 ContentServicePolicies.ON_CONTENT_UPDATE,
                                 ContentModel.ASPECT_AUDITTRAIL,
                                 new JavaBehaviour(this, "onContentUpdate"));
    }
   
   public void onContentRead(NodeRef nodeRef)
   {
      AlfrescoTransactionSupport.bindListener(this);

        String currentUser = this.authenticationService.getCurrentUserName();
      Date now = Calendar.getInstance().getTime();
      
      Map<QName, Serializable> auditItemProps = new HashMap<QName, Serializable>();
      auditItemProps.put(ContentModel.PROP_AUDITEVENT, AuditTrailEvents.AUDIT_EVENT_READ);
      auditItemProps.put(ContentModel.PROP_AUDITUSER, currentUser);
      auditItemProps.put(ContentModel.PROP_AUDITTIMESTAMP, now);

        Map<NodeRef, Map<QName, Serializable>> auditItems = getTransactionAuditItems();
        auditItems.put(nodeRef, auditItemProps);
   }

    public void onContentUpdate(NodeRef nodeRef)
    {
        AlfrescoTransactionSupport.bindListener(this);

        String currentUser = this.authenticationService.getCurrentUserName();
      Date now = Calendar.getInstance().getTime();

      Map<QName, Serializable> auditItemProps = new HashMap<QName, Serializable>();
      auditItemProps.put(ContentModel.PROP_AUDITEVENT, AuditTrailEvents.AUDIT_EVENT_UPDATE);
      auditItemProps.put(ContentModel.PROP_AUDITUSER, currentUser);
      auditItemProps.put(ContentModel.PROP_AUDITTIMESTAMP, now);

        Map<NodeRef, Map<QName, Serializable>> auditItems = getTransactionAuditItems();
        auditItems.put(nodeRef, auditItemProps);
    }
   
    /**
     * @param policyComponent  the policy component
     */
    public void setPolicyComponent(PolicyComponent policyComponent)
    {
        this.policyComponent = policyComponent;
    }
    
    /**
     * @param authenticationService  the authentication service
     */
    public void setAuthenticationService(AuthenticationService authenticationService)
    {
        this.authenticationService = authenticationService; 
    }
    
   public void setAuditTrailService(AuditTrailService auditTrailService)
   {
      this.auditTrailService = auditTrailService;
   }


    public void flush()
    {
        //NO OP
    }

    public void beforeCommit(boolean readOnly)
    {
        //NO OP
    }

    public void beforeCompletion()
    {
        //NO OP
    }

    public void afterCommit()
    {
        Map<NodeRef, Map<QName, Serializable>> auditItems = getTransactionAuditItems();

        for(NodeRef ref : auditItems.keySet())
        {
            Map<QName, Serializable> props = auditItems.get(ref);
            this.auditTrailService.createAuditTrailEntry(ref, props);
        }

        AlfrescoTransactionSupport.unbindResource(AUDIT_TRAIL_ITEMS);
    }

    public void afterRollback()
    {
        //NO OP
    }

    private Map<NodeRef, Map<QName, Serializable>> getTransactionAuditItems()
    {
        Map<NodeRef, Map<QName, Serializable>> auditItems = (Map<NodeRef, Map<QName, Serializable>>)AlfrescoTransactionSupport.getResource(AUDIT_TRAIL_ITEMS);

        if(auditItems == null)
        {
            auditItems = new HashMap<NodeRef, Map<QName, Serializable>>();
            AlfrescoTransactionSupport.bindResource(AUDIT_TRAIL_ITEMS, auditItems);
        }

        return auditItems;
    }
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

However, now the creation of the audit trail entry is not behaving nicely. It is actually quite strange, there is no error thrown, it just doesn't work.

auditTrailService.createAuditTrailEntry:


public NodeRef createAuditTrailEntry(NodeRef auditedItem, Map<QName, Serializable> auditTrailProps)
   {
      NodeRef auditTrailItem = null;
      
      try
      {

         // get the content id
         String contentId = (String)this.nodeService.getProperty(auditedItem, ContentModel.PROP_NODE_UUID);
         
         // add the content id to the properties
         auditTrailProps.put(ContentModel.PROP_AUDITEDNODEID, contentId);
         
         // create the audit trail item
         auditTrailItem = this.nodeService.createNode(
               getAuditTrailContainer(), ContentModel.ASSOC_CHILDREN,
               ContentModel.TYPE_AUDITTRAILITEM, ContentModel.TYPE_AUDITTRAILITEM,
               auditTrailProps).getChildRef();   
      
      }
      catch(Exception e)
      {
         System.out.println(e);
      }
      
      
      return auditTrailItem;
   }
‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

topic Concurrent Modification Exception in Alfresco Archive

Concurrent Modification Exception

Re: Concurrent Modification Exception