private Object toJsonCompatible(Object value) { if (value instanceof Node) { final Node node = (Node) value; final Map<String, Object> result = SubGraph.toMap((PropertyContainer) node); result.put("_id", node.getId()); final List<String> labelNames = SubGraph.getLabelNames(node); if (!labelNames.isEmpty()) result.put("_labels", labelNames); return result; } if (value instanceof Relationship) { final Relationship relationship = (Relationship) value; final Map<String, Object> result = SubGraph.toMap((PropertyContainer) relationship); result.put("_id", relationship.getId()); result.put("_start", relationship.getStartNode().getId()); result.put("_end", relationship.getEndNode().getId()); result.put("_type", relationship.getType().name()); return result; } if (value instanceof Map) { @SuppressWarnings("unchecked") Map<String, Object> map = (Map<String, Object>) value; final Map<String, Object> result = new LinkedHashMap<>(map.size()); for (Map.Entry<String, Object> entry : map.entrySet()) { result.put(entry.getKey(), toJsonCompatible(entry.getValue())); } return result; } if (value instanceof Iterable) { final List<Object> result = new ArrayList<>(); for (Object inner : (Iterable) value) { result.add(toJsonCompatible(inner)); } return result; } return value; }