@Override
	public TypedValue read(EvaluationContext context, Object target, String name) throws AccessException {
		Tuple tuple = (Tuple) target;
		boolean hasKey = false;
		Object value = null;
		if (tuple.hasFieldName(name)) {
			hasKey = true;
			value = tuple.getValue(name);
		}
		else {
			Integer index = maybeIndex(name, tuple);
			if (index != null) {
				hasKey = true;
				value = tuple.getValue(index);
			}
		}
		if (value == null && !hasKey) {
			throw new TupleAccessException(name);
		}
		return new TypedValue(value);
	}
Return an integer if the String property name can be parsed as an int, or null otherwise.
spring-xd-tuple/src/main/java/org/springframework/xd/tuple/spel/TuplePropertyAccessor.java