Friday, March 8, 2013

Webcenter Menu: invalidate cache

We where getting an exception when executing some code that worked on PS3 on PS5. (We are reconstructing our menu based on user roles and we can masquerade as another user on click of a button)

The stack trace of the error included:



<SiteStructureResource><getChildren>
javax.naming.NamingException [Root exception is java.lang.NullPointerException]
at oracle.adfinternal.rc.jndi.CatalogContextWrapper.listBindings(CatalogContextWrapper.java:654)
at oracle.adfinternal.rc.jndi.CatalogContextWrapper.listBindings(CatalogContextWrapper.java:616)


Caused by: java.lang.NullPointerException
at oracle.adfinternal.rc.jndi.FolderContext.loadCache(FolderContext.java:338)
at oracle.adf.rc.spi.jndi.InMemoryContext.checkCacheLoaded(InMemoryContext.java:1401)
at oracle.adfinternal.rc.jndi.FolderContext.loadCache(FolderContext.java:383)

java.lang.reflect.InvocationTargetException
at sun.reflect.GeneratedMethodAccessor916.invoke(Unknown Source)





  public void refreshMenu() {

        SiteStructure model = SiteStructureContext.getInstance().getCurrentModel();
        model.invalidateCache();
        if (this.getLeftMenu() != null)
            AdfFacesContext.getCurrentInstance().addPartialTarget(this.getLeftMenu());
  }


This may not be the best solution but it is a good workaround for what I think is a bug in PS5.





public void refreshMenu() {
        SiteStructure model = SiteStructureContext.getInstance().getCurrentModel();
        model.invalidateCache();
    redirectCurrentPage();
}




public static void redirectCurrentPage() {

  FacesContext fctx = FacesContext.getCurrentInstance();
  ExternalContext ectx = fctx.getExternalContext();

  ControllerContext controllerCtx = null;
  controllerCtx = ControllerContext.getInstance();
  String activityURL =   controllerCtx.getGlobalViewActivityURL(fctx.getViewRoot().getViewId());

  try{
    ectx.redirect(activityURL);
  } catch (IOException e) {
    //Can't redirect
    e.printStackTrace();

  }
}



References:
https://blogs.oracle.com/jdevotnharvest/entry/how_to_efficiently_redirect_an

2 comments:

  1. Hi Donovan,

    Did you get the root cause of this exception? we are facing the same issue in our code.

    Thanks,
    Kailash

    ReplyDelete
    Replies
    1. Yes and no I stopped inside the web center code and left it because of the work around. From what I could see it is a timing issue the invalidated cache is accessed in the adf life cycle before being regenerated.

      Delete