@Override
    protected void writeCollectionIdTo(Output output, int fieldNumber,
            Class<?> clazz) throws IOException
    {
        final CollectionSchema.MessageFactory factory = collectionMapping
                .get(clazz.getName());
        if (factory == null && clazz.getName().startsWith("java.util")
            && CollectionSchema.MessageFactories.accept(clazz.getSimpleName()))
        {
            // jdk collection
            // better not to register the jdk collection if using this strategy
            // as it saves space by not writing the full package
            output.writeString(fieldNumber, clazz.getSimpleName(), false);
        }
        else
        {
            output.writeString(fieldNumber, clazz.getName(), false);
        }
    }
Used by {@link RuntimeSchema#map(Class, Class)}.
protostuff-runtime/src/main/java/io/protostuff/runtime/DefaultIdStrategy.java