how to know if a json object contains a json object - java

I am a novice in java and I am looking for a way to know if a json object contains another jsonObject by using json.org library (not json.org.simple).
For the moment I am using this :
JSONObject json= new JSONObject();
json.has("JsonFieldName");
but but I need to know if there is a way to not specify the Json field Name
If you have a better solution with Json.org, I will take.
Thanks

You can get an Iterator for all the keys in the object from keys, and loop through them seeing if any of the values for the keys is a JSONObject (as opposed to a JSONArray or primitive).
for (String key : json.keys()) {
if (json.get(key) instanceof JSONObject) {
// Yes, it contains at least one JSONObject, whose key is `key`
}
}

Related

Java, map a json

Here's what I wanna do
I have a json, like:
{
"demoNumber":123,
"demoText":"asdasdasd"
}
and I wanna make a simple String array from it, which should be
["demoNumber","demoText"]
In the app we're making the user can add any type of data, so we can't do data models for everything, that's not an option
I have added json to my Gradle:
dependencies {
implementation 'org.json:json:20180130'
}
But it still can't find the method.
Assuming you have the JSON as a string, this example uses the JSON-java library:
JSONObject jo = new JSONObject(myJsonStr);
Set<String> keys = jo.toMap().keySet();
// You should be able to extract an array from the set of keys
See also https://www.baeldung.com/java-org-json

How to parse a jsonObject or Array in Java

I have an API request from my CRM that can either return a jsonObject if there is only one result, or a jsonArray if there are multiple results. Here are what they look like in JSON Viewer
JsonObject:
JsonArray:
Before you answer, this is not my design, it's my CRM's design, I don't have any control over it, and yes, I don't like how it is designed either. The only reason I am not storing the records in my own database and just parsing that, which would be MUCH easier, is because my account is having issues not running some workflows that would allow me to auto add the records. Is there any way to figure out if the result is an object or an array using java? This is for an android app by the way, I need it to display the records on the phone.
You should use OPT command instead of GET
JSONObject potentialObject=response.getJsonObject("resuslt")
.getJsonObject("Potentials");
// here use opt. if the object is null, it means its not the type you specified
JSONObject row=potentialObject.optJsonObject("row");
if(row==null){
// row is json array .
JSONArray rowArray=potentialObject.getJsonArray("row");
// do whatever you like with rowArray
} else {
// row is json object. do whatever you like with it
}
ONE
You can use instanceof keyword to check the instances as in
if(json instanceof JSONObject){
System.out.println("object");
}else
System.out.println("array");
TWO
BUT I think a better way to do this is choose to use only JSONArray so that the format of your results can be predicated and catered for. JSONArrays can contain JSONObjects. That is they can cover the scope of JSONObject.
For example when you get the response (either in a JSONObject or a JSONArray), you need to store that in an instance. What instance are you going to store it in? So to avoid issues use JSONArray to store the response and provide statements to handle that.
THREE
Also you can try method overloading in java or Generics
Simplest way is to use Moshi, so that you dont have to parse, even in the case of the Model changing later, you have to change your pojo and it will work.
Here is the snippet from readme
String json = ...;
Moshi moshi = new Moshi.Builder().build();
JsonAdapter<BlackjackHand> jsonAdapter = moshi.adapter(BlackjackHand.class);
BlackjackHand blackjackHand = jsonAdapter.fromJson(json);
System.out.println(blackjackHand);
https://github.com/square/moshi/blob/master/README.md

Converting JSONObject to JSON using GSON

I am having an Java Object which consist many type of variables including a JSONObject.
Whan i debug my object i got the following String for JSONObject:-
{"INCLUSIONS":{"OPTIONS":[{"display":"Complimentary stay for children under 5 without extra bed"}]}}
But when i used:-gson.toJson(JSONObj),I got following
{"myHashMap":{"INCLUSIONS":{"myHashMap":{"OPTIONS":{"myArrayList":[{"myHashMap":{"display":"Complimentary stay for children under 5 without extra bed"}}]}}}}}
Someone please can elaborate why it is converting JSONObject to Map & list ??
Or Any work Around ??
Thanks.
Just use myJsonObj.toString() instead of myJsonObj.toJSON()
Your problem happens because a JSONObject is stored as a HashMap to allow the programmer to reach values with methods based on keys. As example,
String jsonStr = "{'key': 'value'}";
JsonObject json = gson.fromJson(jsonStr, JsonObject.class);
String value = json.get("key").getAsString();
You can figure that json attributes are stored as a HashMap<JsonElement>

JSON Parsing problem

Hey,
Im trying to parse the following JSON data:
{"chat":
{"link":
[{"#rel":"next","#ref":"http"}],
"events":
{"link2":
[{"#rel":"next","#ref":"http"}]}
}}
The code that reads the data is (where 'a' is the JSON as String):
JSONObject jsonObject1 = new JSONObject(a);
JSONObject jsonObject = jsonObject1.getJSONObject("chat");
So the structure (at least the way I intended) is:
<chat>
<link>
<events>
<link2>
</events>
</chat<
But, after getJsonObject("chat"), jsonObject equals to:
{"chat":{"events":{"link2":[{"#ref":"http","#rel":"next"}]},"link":[{"#ref":"http","#rel":"next"}]}}
What am I missing? Why does the data flips and the structure changes?
The properties in a JSON object are not sorted. From the JSON site:
An object is an unordered set of name/value pairs...
(My emphasis) Therefore the position of link and event are irrelevant for the parser. Bottom line, link and event are at the same level therefore they can be shifted and wherever order matters use arrays in JSON ... [].

json official java api : JSONArray of JSONObjects

Salaam,
Using json.org API, we can easily convert a map to a JSON object :
Map<String, String> carta = new Map<String, String>();
carta.put( "id", "123");
carta.put( "Planet", "Earth");
carta.put( "Status", "getting dirty");
JSONObject json = new JSONObject();
for(Iterator<String> it=input.keySet().iterator(); it.hasNext();){
String key = it.next();
json.put(key, input.get(key));
}
System.out.println(json.toString());
// output: {id:"123", Planet:"Earth", Status: "getting dirty"}
Now we want to have an array of these object
The API doesn't provide this does it?
At least, adding JSONObjects to a JSONArray removes the brackets :
JSONArray joArr = new JSONArray();
joArr.put( cartaEarth );
joArr.put( cartaMars );
System.out.println( joArr.toString() );
//output: [{ id:123, Planet:Earth, Status: getting dirty }, {id: 456, Planet:Mars, Status: maybe aliens there }]
without brackets...while in the API they mention:
put(java.util.Map value)
Put a value in the JSONArray, where the value will be a JSONObject which is produced from a Map.
instead of doing it byhand, preferred to discuss it first, thanks in advance!
have you try GSon ? it is specialized in Java Object to JSon and Json to Java Object.
I would recommend looking at something else than org.json package. Pretty much all alternatives from org.json list provide more convenient and simpler ways to work with JSON.
Aside from Gson that some like, I would recommend Jackson; and flex-json and Svenson are other packages that seem decent.
If you insist on doing this using org.json, you need to explain your problem bit more -- API has all the methods you need, and they do allow you to add values of all types (JSON arrays, objects, strings, numbers, booleans and nulls). But your types need to match JSON types, so there are no conversions from arrays to objects, for example.

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