EObject receiveInteraction(String name, Map<String, byte[]> attributes) {
    // name --Is the name of an EMF class, which is on the classpath along with 
   //      many others.
   // attributes -- Are name value pairs always primitive. Assume they are valid.
   // I need to get these method parameters turned into my return value.

  return eObject;
} 

String packageName = "myPackage";
String interactionName = "myInteraction";
EPackage ePackage = Registrar.getPackageRegistry().getEPackage(packageName);
EClassifier eClassifier = ePackage.getEClassifier(interactionName);
EClass eClass = (EClass) eClassifier;
EObject eObject = EcoreUtil.create(eClass);

String = attributeName = "myAttribute";
byte[] attributeValue = <a stream of bytes>;
EAttribute eAttribute = (EAttribute) eClass.getEStructuralFeature(attributeName);
EDataType eDataType = eAttribute.getEAttributeType();
Object obj = EcoreUtil.createFromString(eDataType, new String(attributeValue);
eObject.eSet(eAttribute, obj);