I have a problem, because my application has connected to BLE device, and my device is sending message to application with part JSON.
For example:
<1;json part 1;checksum> ,<1:json part 2; checksum>
And etc.
I don't know how I can save and join this part. I thought, that I should to use Room library for this, but this is not good idea surely.
I think what you're trying to accomplish is constructing a JSONObject. A JSON object helps you store your data as a single object and assign keys to each object in order to access them. Also JSON is known as one of the common languages for a client and server to talk and transfer data more easily in a condensed way.
Here is an example of using JSON object in Java:
JSONObject jsonObject = new JSONObject();
jsonObject.put("1", "A sample string");
jsonObject.put("2", 1234);
jsonObject.put("AnEmptyObject", new JSONObject());
jsonObject.put("AnEmptyArray", new JSONArray());
Which results in the following JSON:
{
"1": "A sample string",
"2": 1234,
"AnEmptyObject": {},
"AnEmptyArray": []
}
Related
I am facing strange problem with Google Volley I hope some one help me out quickly. I want to send JSON array in parameter and server will give me response in JSON object. How can we achieve this?
e.g
I wanted to post this JSON array.
[
{
"name":"John",
"age":"30",
"cars":"6"
},
{
"name":"John",
"age":"30",
"car
}
]
and server will send response in JSON object format like this.
{
"status":"success",
"code":30,
}
Can someone explain to me how I can achieve this thing?. Moreover, my JSONarray consist of mobile contacts and size will be large.
You can use Map<Object, Object> where value be collection of json Element you want. You can make custom deserilizator with lib like "gson".
You should try: JSONArray arr = new JSONArray(JSON_STRING);
I have a JSON which is returned from a Web Service Developed in PHP but I need help to converting this JSON to JSONArray in Android
{"Name":"John","Contact":"3331234567"}{"Name":"Doe","Contact":"3017654321"}{"Name":"Smith","Contact":"3001234765"}
How can i convert this String returned from URL to JSONArray
Thank you Guys for giving me an idea to fix this problem. I have figured it out bu conceding a string e.g: "n" while writing response on my web service now i can split this on my Android App.
I'd suggest to return it from the web service as a standard JSON Array, which means:
[{"Name":"John","Contact":"3331234567"},{"Name":"Doe","Contact":"3017654321"},{"Name":"Smith","Contact":"3001234765"}]
In this case you can parse it with any common json parser easily (gson, org.json, any other).
Returning it as you do it now produces invalid JSON - just put it to any online JSON validator and it will complain about this.
1. I suggested you to create json file in standard mode
like this:
{
"USER":[ {
"Name":"John",
"Contact":"3331234567"
}
{
"Name":"Doe",
"Contact":"3017654321"
}
{
"Name":"Smith",
"Contact":"3001234765"
}]
}
if you have not any field more , you can remove "USER":
2. You should use json parser library like GSON
**3.**use "pojo" site for create json model in java like http://www.jsonschema2pojo.org/
I'm currently deveolping an Android application that has Django framework as it's server side.
When i'm posting a data of a new user to my database i am POSTing a multipart request that has a user part inside.
The user for some reason is represented as a list but when i take it out of the request.data['user'] it's a str instance (Yea i dont know why...)
When i fetch that str i started working on it with json package.
I looked up on the internet (to many places..) how to convert a string in json format to a dictionary.
What i found is that when you use the json.loads command it doesn't give a dict back but a str instance :)
This is the code on my server side when i enter the create function of the ModelViewSet that handles the creation of the user.
userJson = request.data['user']
userJson = json.dumps(userJson)
userJson = json.loads(userJson)
What i tried to do is to make a string of my own in JSON format and that called the json.loads() command which gave me the dict object..
There seems to be a problem with processing the str from the http request of django rest framework for some reason or there's something else i am not seeing.
I tried the following links -
Converting JSON String to Dictionary Not List
http://docs.python-guide.org/en/latest/scenarios/json/
Didn't worked also..
Now, i tried accessing the str i got from json.loads() like a dictionary in this way.
id = userJson['id']
Now lets say maybe i passed a wrong json format to the loads function, it should have thrown an exception..
The code above (getting the id) raised an exception of 'String indices must be integer' - it doesn't convert it to dict! LOL xD
Good note worth mentioning - I'm trying to convert the json to a dictionary so i could access it like this - dictObject['id']
Well i would really appreciate every help!
Thanks :)
For some reason , when i did this commands-
userJson = request.data['user']
userJson = json.loads(userJson)
userJson = json.loads(userJson)
What i got to have inside the userJson after the second json.loads(userJson) I got the actual dict object to the userJson member.
Appearently it is a bug.
21 January - another update, I truly was doing double Json encoding on the Android application so that was the reason for double json. loads()
I have an XML web service. I want to parse this XML and I want to store in an separate textviews. The following is an XML content, and I have finished getting it in a String variable.
{
"30_year_rate": 4.25,
"30_year_pi": 196.78,
"30_year_apr": 4.375,
"20_year_rate": 4.375,
"20_year_pi": 250.37,
"20_year_apr": 4.5,
"15_year_rate": 3.75,
"15_year_pi": 290.89,
"15_year_apr": 3.875,
"10_year_rate": 3.625,
"10_year_pi": 397.89,
"10_year_apr": 3.75,
"5_year_arm": 2.75,
"5_year_pi": 163.3,
"5_year_apr": 2.875,
"7_year_arm": 3,
"7_year_pi": 168.64,
"7_year_apr": 3.125,
"3_year_arm": 4,
"3_year_pi": 190.97,
"3_year_apr": 4.125,
"5_year_io_arm": "N/A",
"5_year_io_pi": "N/A",
"5_year_io_apr": "N/A",
"QuoteID": 1449,
"Licensed": "N"
}
How can I parse this data? I want to convert it to a JSON object and retrieve it, or any other reasonable approach.
If what you're getting back from the webservice is the string above, then you already have a JSON string. To create an object that can retrieve information from it, use something like JSONObject.
JSONObject object = new JSONObject(your_string_variable);
double thirtyYearRate = object.getDouble("30_year_rate");
String licensed = object.getString("Licensed");
etc.
You might (will) run into some issues where you try to pull a double from a JSON field that contains a string; i.e., the "N/A" fields above. You'll likely have to pull them out as strings and then try to parse doubles from them, and if the parsing throws an exception, you'll know it's a string.
Alternately, you could look into JSON binding with something like Jackson, which apparently runs on Android.
To parse JSON, you could use the built in JSONObject org.json Or Json-lib if you use an old version of android.
To parse XML, use XMLPullParser. A sample can be found here: Parsing XML Data
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.