Develop Reference

Json Object: linked list?

I have a Json string:
String json = "{\"I\":0,\"lst\":[{\"i1\":100500,\"s1\":\"abrakadabra\",
\"aList\":[{\"text\":\"secret will of my Dad\"}]}]}";
JSONObject o = new JSONObject(json);
My question: how, using Json Obj methods, to browse through each node element recursively?

Vitali, I don't have enough reputation points to reply to your comment, so posting it as an answer. In that post I linked, I meant the code snippet with loopThroughJson() method. I haven't tried it myself but that looks right. For completeness, this is the link again -
Recursively parsing JSON via JSONObject to fetch value against specific keys

Loop through the object, get child as reference of Object class using the get() method, if that object is instance of JSONObject or JSONArray, go deeper.

Iterating through JsonObject in Java/Android. NOT JsonArray

Here's my JSON data sample:
{
"node_1.1":{
"someCrap":{
"someCrap":"SomeValue"
}
},
"node_1.2":{
"Node_1.2.1":{
"Node_1.2.1.1":{
"param1":value,
"param2":value,
"param3":"value",
"paramThatIneed":{
"ThisIsWhatIActuallyNeed":"url",
"width":96,
"height":72
}
},
"Node_1.2.1.2":{
Same as above, just that paramThatINeed might be missing, gotta place imagePlaceHolder Here
},
//and so on... there are a total of 50 of these..
}
}
}
Now I could get the node_1.1 and Node 1.2 and the sub-node of it node_1.2.1
However, there are 50 sub-nodes inside of node_1.2.1, and they will have random names returned from the server. Its in string format but they're actually ints. Its a page ID.
Now I wanna iterate through the node_1.2.1 and get those sub-nodes and access their sub-nodes and take in the URL of the paramThatINeed. If the paramThatINeed is not present, I need to put some null/dummy value.
This is the code that I tried to work it as far as I've reached:
JSONObject jsonObj = new JSONObject(jsonStr); //jsonStr is the entire JSON string
JsonObject node_1.2= jsonObj.getJsonObject("node_1.1");
JsonObject node_1.2.1 = node_1.2.getJsonObject("node_1.2.1");
What do I do after this? Because I can only getJsonObject by passing a string param to it, I tried using the for loop but it doesn't take any int param.
Also, as I said before, the nodes after that have random names and not fixed. So I'm totally confused.
Please help me out if you know how to solve this problem. Please remember there's no JsonArray in this. I'm probably thinking of editing the JSON string itself and replacing some parts of the '{' with '[' and converting it to an array :( ... I think that's a sad approach.

Use this to iterate over an object.
Android (JSONObject) How can I loop through a flat JSON object to get each key and each value
but be careful, from json object you won't get the result in original order, like in json array. The result will be in alphabetical order (I hope I was clear). And you can use optJsonobject(), instead of getJsonObject(). It will returns null, instead of throw exception. You can use opt every where instead of get.

Accessing an object from JSON in Android

I have a question that I am a little bit confused about. I am quite new to JSON and getting JSON values in the android API. I am trying to access an array within the response I get. the JSON code I am getting is something like this:
Response:
{
"event": {
"participants": []
},
"status": "success"
}
How would I access the participants array and store their values. This is what I am trying at the moment... but I dont appear to be getting what I want.
try{
//get the JSON values from the URL.
JSONObject json = jParser.getJSONFromUrl("http://somesite.com/api/find?"+"somevar="+someJavaStringVar);
json_event = json.getJSONObject("event");
JSONArray json_array_participants = json_event.getJSONArray("participants");
} catch(JSONException e) {
}
The thing I am mostly confused about is... what is the arrays type equivalent to. Any advice or reasoning as to the correct way to get ahold of that variables value would be great... thanks guys.. :).

Think JSON is really just a key-value pairing. The JSONArray type is just an array full of objects (like Object[]) - it has no idea what the objects it contains are or what they're to be used for. Its up to you to assign meaning to the JSON stream based on what you know of the source. From what I see of your code, most of it looks fine, though I don't know what your jParser.getJSONFromURL() is doing. Typically, you would build the JSON from the response string like so:
String jsonString = getJSONFromUrl("http://somesite.com/api/find?"+"somevar="+someJavaStringVar);
JSONObject json = new JSONObject(jsonString)
JSONObject json_event = json.getJSONObject("event");
JSONArray json_array_participants = json_event.getJSONArray("participants");
You can iterate through the array like any other array to get subobjects or whatever:
for(int i=0; i < json_array_participants.getLength(); i++) {
JSONObject participant = json_array_participants.getJSONObject(i);
// Do stuff
}
As a side note - I WOULDN'T use GSON until you understand the underlying protocol, at least a little - because you never know when you might want to parse your JSON from a different language for some reason.

I would strongly recommend to use gson instead as your preferred parser since it will do all the job of serializing and deserializing for you except creating the domain objects.
This tutorial should get you going:
http://www.javacodegeeks.com/2011/01/android-json-parsing-gson-tutorial.html

This will depend on what the server is supposed to return. It could be an array of anything and if this is a public service, there should be a specification to go off of.
If you are in charge of the server portion as well, and you have a backing object, Google's GSON library is extremely easy to use. It will also keep type information straight.

json parsing in android of web data

I have to parse this json data. The data begins with [ and ends with ]
How can we parse such json data? json data usually starts with {..[..]..}

Just create a JSONArray from your input. There is even a constructor taking a String as parameter. So, basicly you need to do something like this:
String input = .. //read your input
JSONArray arr = new JSONArray(input);
//work with the array as usual..

take result data as a JSONArray and not a JSONObject.

It depends on how you parse the data. Built in json or google json(gson) etc.
But normally you dont have to care about that it starts with square bracket.
Show me what the json array/object look like and I can give you an example.

JSON Parser Android

JSONObject jObject = new JSONObject(myJsonContent);
JSONObject menuObject = jObject.getJSONObject(String.valueOf(jObject.keys().next()));
myJsonContent is response from server
and i dont know what is start tag ... and i dont want to know even...
and after that without knowing any tag of response i want to parse response..
this is requirment because in the future we will not be knowing if server guys change data and tags as well so we need to create like this which will be work even if server guys changes all the tags in future
please help me any kind of help is very appriciable

You should check here,
http://developer.android.com/reference/org/json/JSONObject.html
get keys from json object i.e. iterator and loop thorough it and use jsonObject.names() to get the array of names. This should guide you to the right solution.

Sorry for the plug, but you could try do what I did - use this parsing object generator