Develop Reference

I don't know how to classify JSON data in Android

I'm a newbie in Android. I'm making a crypto currency tracker. I'm using a Korean exchange API. But, when I read JSON data as String, it's a little different from what I found in literature.
In the red bracket, there are some data but are classified as the String like "BTC, ETH". And I learned in a book like this
String timestamp;
String payment_currency; // payment currency(USD, KRW...)
ArrayList<BidAskBithumb> bids = new ArrayList<BidAskBithumb>(); // Bids
ArrayList<BidAskBithumb> asks = new ArrayList<BidAskBithumb>(); // Asks
Every property is saved in String and Arrays. But in that JSON data, there is currency's name like BTC or ETH after payment_currency String. I don't know I have to make every class file like BTC.java or ETH.java. How can I solve this?
This is the JSON response I'm getting.
I read all the currency's data:
The original API documentation link.

I don't know I have to make every class file like BTC.java or ETH.java. How can I solve this?
No, you dont have to create new class files for them, you need to create model class according to your json file. & handle its behaviour.
You can try this to create your model.

output text line by line

I write app for Android such gets data from server in JSON format. Now I get this value in string, but in my application it must look like:
Route:
1)first point
2)secon point
3).....
n) n point
I read that in Android in textView I can do it if string will be with html tags but I think it is not the best variant. After Android I must do it in iPhone now I don't know how to do that there. Send Routes as Array is not good variant too. Can you say what is the best way to decide this problem?

Have a look here you will have to find the good pattern .
Hence you have separated strings just use a list View with an ArrayAdapter.
I am not so good with regex but i think it should like : [1-9][0-9]) [[a-f][0-9]]+

I couldn't comment b/c of rep, sorry. Could you provide an example of returned JSON string. I think JSON format can be parsed with ease.
If this the case you can parse it in a loop (or another way. I'm not that good at it)
String[] parseIt (String JSON){
String[] list=JSON.split("\\d\\)");
String[] rlist=new String[list.length-1];
for(int i=0;i<list.length-1;i++){
rlist[i]=list[i+1].trim();
}
return rlist;
}
This might do trick. But you should edit result. I didn't test yet
Edit: I edited code. It simply return the address now with leading whitespace. You can get rid off them using. String trim() method like;
list[1].trim();
Do it in loop and don't care about first element (index 0).
Edit 2: Now it should work

Comparison - XML with JiBX or JSON with Jackson?

I need to import data from a file to my application. The obvious choices are XML and JSON. I have heard that JSON is lightweight and when parsed with Jackson, it gives good performance. But I have also heard that JiBX for XML is fast and uses XMLpull to give good performance. I would like to know which option to go for and why?. Can I get a speed comparison of XML with JiBX and JSON with Jackson? Also, I want to know if Google Gson is better than Jackson for JSON parsing.

Json is the light weight.If you want to use large documents use, JSon with Jackson.
Excellent explanation been given in this article(especially read Note:). Xml you have
different types like DOM,PULL and SAX.But as per my knowledge, JSON is the best. For Large
documents,prefer Jackson. http://www.javabeat.net/2011/05/androids-json-parser/
For Jackson and gson. Have a glance of this link.
Jackson Vs. Gson
So when comparing with xml and json,i always suggest you to use json, since it's a light weight data for android. So it will be fast in loading and display the data. And gson,
it depends based on your project. Please see the above link comparsion.you will cleanly understand.

In addition, Jackson can also do XML if that's what you need, with https://github.com/FasterXML/jackson-dataformat-xml
I also agree in that Jackson+JSON will be faster than any of XML-based solutions (as per https://github.com/eishay/jvm-serializers). JibX is not bad and probably is fast enough for most uses (as do many, many other options). But if speed is your thing, Jackson will be faster of choices you mention.

I agree that in pure performance, JSON is going to be faster than JiBX.
You choice of tools should depend on the data you are transferring.
Use JiBX if you have a concrete data definition. JiBX is especially good at creating and retrieving complex data objects. JiBX will make sure your data is correct and automatically convert your data to and from Java objects.
Use JSON if you want more flexibility. JSON doesn't check to see if your data is correct.
For example, when you create an object in JiBX:
Person person = new Person();
person.name = "Don";
person.age = 52;
When you retrieve the information in JiBX:
System.out.println("Name: " + person.name);
System.out.println("Age: " + person.age);
In JSON, your code would look like this:
JSONObject person = new JSONObject();
person.put("name", "Don");
person.put("age", new Integer(52));
To retrieve the transmitted information:
String name = person.get("name");
long age = person.get("age");
As you can see, the JiBX code is nicer to read, but the JSON is more flexible since you don't have a schema definition.
In either solution, your code is exactly the same in your Android client and your java service/server.
I hope this helps.
Don Corley - JiBX contributor

Converting multiple datas into a single string for uploading using json in android

I have to submit data from 30 pages into the server.These datas from 30 pages are to be made into a single string and that i have to upload that single string into the server using json.
Each page may contain many answers tht may be either in plain text(value we receive from edit text),from check boxes(yes or no) and so on.....please suggest me a way to add all these data into a single string and upload it using json.

Based on the comment I suspect that you believe that you need to treat these "pages" as strings that you concat. However, what I think you're overlooking is that JSON is pretty versatile in how you add objects to it.
So, let's say you have the thing that you want to ship to your server and you call it
JSONObject myEntireFile = new JSONObject();
you can now add stuff to it at any time like this...
JSONObject page1 = new JSONObject();
myEntireFile.put("page1", page1);
meanwhile you can put whatever you want IN page 1 (cause that's just another serialized container).
You can keep doing this until you're ready to send it, at which time you just call
myEntireFile.toString();
which will convert your object into one long, well formatted, JSON string, that you can then open store for later use.

android - simple way to extract a key-value pair from a json string?

Suppose I have a json string like this:
{ ... "key1":"value1"; ... }
with a key1-value1 pair somewhere deep down the json structure (which includes other things such as array, dictionary, etc...). I don't know exactly (and don't care) how the exact structure of the json is.
Is there a simple way to extract the "value1" ? (if there are 2 "key1" in the json string then I just need the first one).

As far as I know, you have no chance of doing it manually.
If you really don't know what's the structure of the JSON string you're expecting, you can try a graph search approach, such as DFS (http://en.wikipedia.org/wiki/Depth-first_search).
For every key, check if it is an array.
If so, go inside and repeat the procedure. If nothing was found in a given array, backtrack.
Interrupt your process once you have found your key.