Java: Merging two JSON objects without iterating

Question

I have two JSON objects like

{  
   "key1":"value1",
   "key2":"value2",
   "key3":"value3",
   "key4":"value4"
}

and

{
   "key2":"value1",
   "key4":"value2",
   "key6":"value3",
   "key8":"value4"
}

I want to merge these two JSON objects into single Json object without iterating through each key and the final result should be

{
   "key1":"value1",
   "key2":"value1",
   "key3":"value3",
   "key4":"value2",
   "key6":"value3",
   "key8":"value4"
}

what the final outcome you are expecting ?

Shiv Kumar Baghel
– Shiv Kumar Baghel

2018-10-17 04:00:46 +00:00
Commented Oct 17, 2018 at 4:00 — Shiv Kumar Baghel
– Shiv Kumar Baghel, Commented Oct 17, 2018 at 4:00
Question updated

Rahul Ramamoorthy
– Rahul Ramamoorthy

2018-10-17 04:04:40 +00:00
Commented Oct 17, 2018 at 4:04 — Rahul Ramamoorthy
– Rahul Ramamoorthy, Commented Oct 17, 2018 at 4:04

so-random-dude · Accepted Answer · 2018-10-17 04:14:47Z

2

Use any Json Mapper (e.g Jackson) convert json to Map.

ObjectMapper mapper = new ObjectMapper();
Map<String, Object> map = mapper.readValue(json, new TypeReference<Map<String, String>>(){})

once you get two maps like this you can merge them

Map<String, Object> mergedMap = new HashMap<>();
mergedMap.putAll(map1);
mergedMap.putAll(map2);
String json = mapper.writeValueAsString(mergedMap);

edited Oct 17, 2018 at 4:14

so-random-dude

16.8k11 gold badges78 silver badges121 bronze badges

answered Oct 17, 2018 at 4:04

Amit Phaltankar

3,4242 gold badges26 silver badges41 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Rahul Ramamoorthy Over a year ago

Thanks but is there a way to do it without converting to map

so-random-dude Over a year ago

There is no other way. This is the best you can do.

Oswaldo Junior · Accepted Answer · 2022-09-12 03:03:03Z

0

Consider using a library that does this job for you, like JSON Merge, available at Maven Central.

You will get the desired result with a single line of code:

JSONObject result = new JsonMerger<>(JSONObject.class).merge(json2, json1);

Note: the first JSON parameter passed to the merge method will always have more precedence/importance than the second one in case of key collisions.

This library works with Jackson, Gson, and other JSON providers as well.

answered Sep 12, 2022 at 3:03

Oswaldo Junior

1561 silver badge5 bronze badges

Collectives™ on Stack Overflow

Java: Merging two JSON objects without iterating

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related