Develop Reference

How to efficiently merge two JSON Strings based on a common key

I have two JSON strings which are essentially arrays of JSONObject. The two JSON strings have below structure and keys:
JSON-1:
[
{
"title": "ABC",
"edition": 7,
"year": 2011
},
{
"title": "DEF",
"edition": 2,
"year": 2012
},
{
"title": "XYZ",
"edition": 3,
"year": 2013
}
]
And, JSON-2:
[
{
"title": "ABC",
"price": "20"
},
{
"title": "DEF",
"price": "20"
},
{
"title": "XYZ",
"price": "20"
}
]
Both these JSONs have a common key "title" based on which I want to merge these two JSONs, either merging JSON-2 values into JSON-1 or creating a JSON object with the merged result.
The merged result should look like below:
[
{
"title": "ABC",
"edition": 7,
"year": 2011,
"price": "20"
},
{
"title": "DEF",
"edition": 2,
"year": 2012
"price": "20"
},
{
"title": "XYZ",
"edition": 3,
"year": 2013
"price": "20"
}
]
How can I achieve this by minimum looping and minimum object creation? I also can not use entity/model classes. The idea is to do it without creating any model classes.
Note: I cannot use Gson because I don't have the approval to use the same.
I tried to use List<JSONObject> listObj = objectMapper.readValue(jsonOneString, new TypeReference<List<JSONObject>>(){});,
but I am getting an unknown property exception.
I tried JsonNode node = objectMapper.readTree(jsonOneString);, but I cannot proceed much further with this approach.
I know what I am doing here is highly inefficient, so looking for ways which will use no entity class, minimum new object creation and minimum loops. Kindly advise.
UPDATE: I updated the below code with a slight modification:
if (json1elem.get("title")!=null
&& json2elem.get("title")!=null
&& json1elem.get("title").equals(json2elem.get("title"))) {
//
}

JsonNode json1 = objectMapper.readTree(jsonOneString);
JsonNode json2 = objectMapper.readTree(jsonTwoString);
for (JsonNode json1elem : json1) {
for (JsonNode json2elem : json2) {
if (json1elem.get("title").equals(json2elem.get("title"))) {
((ObjectNode) json1elem).setAll((ObjectNode) json2elem);
break;
}
}
}
System.out.println(json1.toPrettyString());

Transform complex Json array using Jolt

When Calling an external API I am receiving a complex json structure, the same I need to transform into a simple json as per our need. I found jolt has the capability to transform a json but not able to come up with the jolt spec.
My input Json array --
{
"attribute": [
"teamalloc",
"prodAlloc"
],
"item": {
"id": "abcde",
"name": "Champak Kumar",
"allocDetails": {
"updatedAt": "2020-08-10T14:26:48-07:00",
"token": 1134,
"items": [
{
"allocation": 0.2,
"team": {
"id": 90,
"name": "Some Team Name 1",
"createdAt": "2010-01-19T10:52:52-07:00"
}
},
{
"allocation": 0.9,
"team": {
"id": 80,
"name": "Some Team Name 2",
"createdAt": "2010-01-19T10:52:52-07:00",
"product": {
"id": 20,
"name": "Some Product Name 1",
"otherDetails": {
"key": "Id",
"value": "GEC"
}
}
}
},
{
"allocation": 0.1,
"team": {
"id": 10,
"name": "Some Team Name 3",
"createdAt": "2010-01-19T10:52:52-07:00",
"product": {
"id": 22,
"name": "Some Product Name 2",
"otherDetails": {
"key": "Id1",
"value": "GEC1"
}
}
}
}
]
}
}
}
My output Json structure should look like --
{
"name": "Champak Kumar",
"allocDetails": [
{
"allocation": 0.2,
"team": {
"id": 90,
"name": "Some Team Name 1"
}
},
{
"allocation": 0.9,
"team": {
"id": 80,
"name": "Some Team Name 2",
"product": {
"id": 20,
"name": "Some Product Name 1"
}
}
},
{
"allocation": 0.1,
"team": {
"id": 10,
"name": "Some Team Name 3",
"product": {
"id": 22,
"name": "Some Product Name 2"
}
}
}
]
}
I tried multiple jolt spec but couldn't come up with the desired output. What should be the ideal jolt spec for this?

This spec should using shift operation should work:
[
{
"operation": "shift",
"spec": {
"item": {
"name": "name",
"allocDetails": {
"items": {
"*": {
"allocation": "allocDetails[&1].allocation",
"team": {
"id": "allocDetails[&2].team.id",
"name": "allocDetails[&2].team.name",
"product": "allocDetails[&2].team.product"
}
}
}
}
}
}
}
]
Edit #1:
The explanation:
The shift operation spec defines where do we want to put the values from the input json in the result json.
Each key - value pair in the spec defines the source - target relation.
For example (let's start from the simplest one): value from the ["item"]["name"] will land under the ["name"] key in the output JSON.
The
"items": {
"*": {
...
}
}
part says: "For each element of the array under the 'items' key do ..."
The ampersand operator "&X" lets us reference the key that is X levels above the LHS (the key in question). For example:
Let's imagine we have the 57th element of the items array (counting from 0):
...
"name": "allocDetails[&2].team.name"
...
says: "Place the value found under the "name" key (that is in item["items"][56]["team"]["name"] in the 57th element of the array placed under the "allocDetails" key.
'*' matches the 57th element. '&2' lets us find out that the element of the array we are working on right now is the 57th element.
Have a look at the shift operation javadocs, especially at the "&" and "*" wildcards
Edit #2:
considering the otherDetails comment:
You could also approach it like this:
...
"team": {
"id": "allocDetails[&2].team.id",
"name": "allocDetails[&2].team.name",
"product": {
"otherDetails": null,
"*": "allocDetails[&3].team.product.&"
}
}
...
the above: puts all of the products' part keys (matched by the "*") to the key with the same name ("&") placed in the "allocDetails[&3].team.product" output json's key... with the exception of the "otherDetails" key.

Working jolt spec --
{
"operation": "shift",
"spec": {
"item": {
"name": "name",
"allocDetails": {
"items": {
"*": {
"allocation": "allocDetails[&1].allocation",
"team": {
"id": "allocDetails[&2].team.id",
"name": "allocDetails[&2].team.name",
"product": {
"id": "allocDetails[&3].team.product.id",
"name": "allocDetails[&3].team.product.name"
}
}
}
}
}
}
}
}
]```

how to create linked hash map object for this json

I am trying to call an API using Retrofit in android. For this API I need the input parameter JSON object in proper sequence.
Only if I have the json in required sequence I get successful response from the API, otherwise it gives an error. To handle this issue I got one solution that is to first create a LinkedHashMap of input parameter then create the JSON of that LinkedHashMap. This way I'm acheaving the response from api.
but right now im confused how to create linkedHash map for below json
{
"RequestXml": {
"Authenticate": {
"InterfaceCode": "1",
"InterfaceAuthKey": "AirticketOnlineWebSite",
"AgentCode": "MOS0000001",
"Password": "KGBW5P"
},
"BookTicketRequest": {
"TrackNo": "0$182967|4|1AO",
"MobileNo": "9099776464",
"AltMobileNo": "9898989898",
"Email": "abc#gmail.com",
"Address": "Test",
"ClientRequestID": "",
"Passengers": {
"Passenger": [
{
"PaxSeqNo": "1",
"Title": "Mr",
"FirstName": "Savan",
"LastName": "Test",
"PassengerType": "A",
"DateOfBirth": "01/12/1992",
"PassportNo": "RTTTTGGBGB56356",
"PassportExpDate": "01/12/2024",
"PassportIssuingCountry": "IND",
"NationalityCountry": "IND"
}
]
},
"Segments": {
"Segment": [
{
"TrackNo":"0$182967|4|1AO",
"SegmentSeqNo": "1",
"AirlineCode": "UK",
"FlightNo": "888",
"FromAirportCode": "BOM",
"ToAirportCode": "DEL",
"DepDate": "30/09/2019",
"DepTime": "14:00",
"ArrDate": "30/09/2019",
"ArrTime": "16:00",
"FlightClass": "E",
"MainClass": "Y"
}
]
},
"AdditionalServices": {
},
"TotalAmount": "4735",
"MerchantCode": "PAY9zJhspxq7m",
"MerchantKey": "eSpbcYMkPoZYFPcE8FnZ",
"SaltKey": "WHJIIcNjVXaZj03TnDme",
"IsTicketing": "Yes"
}
}
}

How to convert the tree structured json to Java object using gson

[
{
"sentence": "I want to buy shoes .",
"tree": {
"ROOT": [
{
"index": 2,
"token": "want",
"label": "VERB",
"pos": "VBP",
"tree": {
"nsubj": [
{
"index": 1,
"token": "I",
"label": "PRON",
"pos": "PRP"
}
],
"xcomp": [
{
"index": 4,
"token": "buy",
"label": "VERB",
"pos": "VB",
"tree": {
"aux": [
{
"index": 3,
"token": "to",
"label": "PRT",
"pos": "TO"
}
],
"dobj": [
{
"index": 5,
"token": "shoes",
"label": "NOUN",
"pos": "NNS"
}
]
}
}
],
"punct": [
{
"index": 6,
"token": ".",
"label": ".",
"pos": "."
}
]
}
}
]
}
}
]
This is tree represented in Json. But the keys for nested nodes keep changing.
For example "ROOT, nsubj, xcomp" ... etc.
How do I convert above json code to Java Object using gson.
Above response is from syntaxnet Parsey_Mcparseface api I'm trying to use.
Thanks in advance.

Gson has a method Gson#fromJson. For example, this is a code to read a simple String object.
Gson gson = new Gson();
String str = gson.fromJson("\"hello\"", String.class);
System.out.println("String: " + str);
You need to prepare Java Object to read your proposed JSON. But, you don't need to write code by yourself. There is a website providing automatical JSON object generator.
jsonschema2pojo
enter following items:
Target language: Java
Source type: JSON
Annotation type: Gson
and enter your class name, for example "ParsedSentence"
then, write code. You will get object.
Gson gson = new Gson();
ParsedSentence parsed = gson.fromJson(longLongJsonString, ParsedSentence.class);

Failure to parse this json field

I can get other fields correctly, but can parse the "title" or "title_full" values. I always receives an empty string. I am using the org.json library. This is the json. What's the trick?
try {
title = jsonDoc.getString("title_full");
} catch (JSONException e) {
log.info("no full title: " + docString);
}
{
"organizations": [],
"uuid": "d0adc516c9012113774557365f9847da99b228e7",
"thread": {
"site_full": "www.fark.com",
"main_image": "http://img.fark.net/images/cache/orig/5/51/fark_514Jh7VFpynQw4MyN2xcK1jwCxk.png?t=RQrnhq8EGZiUuElMitgLOQ&f=1488776400",
"site_section": "http://www.fark.com/discussion/",
"section_title": "FARK.com: Discussion links",
"url": "http://www.fark.com/comments/9500577/I-want-to-support-work-that-NY-Times-Washington-Post-are-doing-I-can-only-afford-one-subscription-Who-do-you-recommend-I-throw-my-support-to?cpp=1",
"country": "US",
"domain_rank": 3382,
"title": "(9500577) I want to support the work that the NY Times and Washington Post are doing. I can only afford one subscription. Who do you recommend I throw my support to?",
"performance_score": 0,
"site": "fark.com",
"participants_count": 31,
"title_full": "FARK.com: (9500577) I want to support the work that the NY Times and Washington Post are doing. I can only afford one subscription. Who do you recommend I throw my support to?",
"spam_score": 0.0,
"site_type": "discussions",
"published": "2017-03-03T12:00:00.000+02:00",
"replies_count": 2,
"uuid": "67213179a24931106e75cd588386bd30fb3bbdc8"
},
"author": "EbolaNYC",
"url": "http://www.fark.com/comments/9500577/I-want-to-support-work-that-NY-Times-Washington-Post-are-doing-I-can-only-afford-one-subscription-Who-do-you-recommend-I-throw-my-support-to?cpp=1#c107765048",
"ord_in_thread": 1,
"title": "",
"locations": [],
"entities": {
"persons": [],
"locations": [],
"organizations": []
},
"highlightText": "",
"language": "english",
"persons": [],
"text": "dionysusaur : Either the NY Post or the WA Times.\nOnly asshats read the NY Post.",
"external_links": [],
"published": "2017-03-03T15:58:00.000+02:00",
"crawled": "2017-03-03T17:05:26.049+02:00",
"highlightTitle": "",
"social": {
"gplus": {"shares": 0},
"pinterest": {"shares": 0},
"vk": {"shares": 0},
"linkedin": {"shares": 0},
"facebook": {"likes": 0, "shares": 0, "comments": 0},
"stumbledupon": {"shares": 0}
}
}

Your JSON seems like follows:
{
{
"main": {
"key": "value",
},
},
}
So, First fetch the main json and then the key.
Code should be like as follows:
String something = jsonDoc.get("main").get("key").toString();
There are two title values in your JSON, Do check which title you need before fetching.

After I formatted the json code, the problem becomes obvious:
title_full is only available inside the thread node, and a non-empty title is also only inside the thread node. So you'll first have to access the thread node and then access title and title_full inside that node.
Using the org.json library, you can access the fields like this:
String fullTitle = jsonDoc.getJSONObject("thread").getString("title_full");

If you take a look at the json you will see that the "title" and "title_full" fields are in the thread field.
So try reading that field and then parsing the filed into a new jsonObject and you should be able to get them.