OADescriptiveFlexBean oaDFF =(OADescriptiveFlexBean)dffCol.findIndexedChildRecursive("SiteUseDFF");
         
    {
 
    oaDFF.processFlex(pagecontext);

    OAWebBean dffbeans0 = (OAWebBean)oaDFF.findChildRecursive("SiteUseDFF0");

      if (dffbeans0 != null)
      {

      dffbeans0.setAttributeValue(OAWebBeanConstants.READ_ONLY_SET, true);
        dffbeans0.setAttributeValue(OAWebBeanConstants.READ_ONLY_ATTR, true);
      }


      OAWebBean dffbeans1 = (OAWebBean)oaDFF.findChildRecursive("SiteUseDFF1");

      if (dffbeans1 != null)
      {

        dffbeans1.setAttributeValue(OAWebBeanConstants.READ_ONLY_SET, true);
        dffbeans1.setAttributeValue(OAWebBeanConstants.READ_ONLY_ATTR, true);
      }
}


https://community.oracle.com/thread/2263077?tstart=0