Java: Merging two json objects together with primary key
My Java is a little rusty but I would use a map.
List<JSONObject> objectsA = ... ;List<JSONObject> objectsB = ... ;Map entries = new HashMap<String, JSONObject>();List<JSONObject> allObjects = new ArrayList<JSONObject>();allObjects.addAll(objectsA);allObjects.addAll(objectsB);for (JSONObject obj: allObjects) { String key = obj.getString("id"); JSONObject existing = entries.get(key); if (existing == null) { existing = new JSONObject(); entries.put(key, existing); } for (String subKey : obj.keys()) { existing.put(subKey, obj.get(subKey)); }}List<JSONObject> merged = entries.values();This is more efficient than two nested loops and there's still room for improvement.
EDIT: References to external documentation and related answers.