The PropertyDefinition object gives the updatability of a property. With OpenCMIS, you can retrieve "cmis:name" updatability like this :
TypeDefinition typeDef = session.getTypeDefinition("cmis:document");
Map<String,PropertyDefinition<?>> propertyDefs = typeDef.getPropertyDefinitions();
PropertyDefinition namePropertyDef = propertyDefs.get("cmis:name");
Updatability nameUpdatability = namePropertyDef.getUpdatability();
if (Updatability.READONLY.equals(nameUpdatability)
throw new Exception("This field can not be upated");
You can have a look on OpenCMIS javadoc for details about updatability values