How to extract value from API [duplicate]

Question

How do I extract a certain value from the following api?

https://blockchain.info/ticker

{
  "USD" : {"15m" : 376.51, "last" : 376.51, "buy" : 376.79, "sell" : 377.61,  "symbol" : "$"},
  "ISK" : {"15m" : 48027.62, "last" : 48027.62, "buy" : 48063.33, "sell" : 48167.93,  "symbol" : "kr"},
  "HKD" : {"15m" : 2933.63, "last" : 2933.63, "buy" : 2935.81, "sell" : 2942.2,  "symbol" : "$"},
  "TWD" : {"15m" : 12551.49, "last" : 12551.49, "buy" : 12560.82, "sell" : 12588.16,  "symbol" : "NT$"},
  "CHF" : {"15m" : 373.09, "last" : 373.09, "buy" : 373.37, "sell" : 374.18,  "symbol" : "CHF"},
  "EUR" : {"15m" : 337.4, "last" : 337.4, "buy" : 337.65, "sell" : 338.38,  "symbol" : "€"},
  "DKK" : {"15m" : 2517.92, "last" : 2517.92, "buy" : 2519.79, "sell" : 2525.27,  "symbol" : "kr"},
  "CLP" : {"15m" : 265459.51, "last" : 265459.51, "buy" : 265656.92, "sell" : 266235.07,  "symbol" : "$"},
  "CAD" : {"15m" : 523.97, "last" : 523.97, "buy" : 524.36, "sell" : 525.5,  "symbol" : "$"},
  "CNY" : {"15m" : 2475.39, "last" : 2475.39, "buy" : 2477.24, "sell" : 2482.63,  "symbol" : "¥"},
  "THB" : {"15m" : 13398, "last" : 13398, "buy" : 13407.97, "sell" : 13437.15,  "symbol" : "฿"},
  "AUD" : {"15m" : 532.81, "last" : 532.81, "buy" : 533.21, "sell" : 534.37,  "symbol" : "$"},
  "SGD" : {"15m" : 530.11, "last" : 530.11, "buy" : 530.5, "sell" : 531.65,  "symbol" : "$"},
  "KRW" : {"15m" : 453073.94, "last" : 453073.94, "buy" : 453410.87, "sell" : 454397.62,  "symbol" : "₩"},
  "JPY" : {"15m" : 43995.46, "last" : 43995.46, "buy" : 44028.18, "sell" : 44123.99,  "symbol" : "¥"},
  "PLN" : {"15m" : 1487.56, "last" : 1487.56, "buy" : 1488.67, "sell" : 1491.91,  "symbol" : "zł"},
  "GBP" : {"15m" : 259.62, "last" : 259.62, "buy" : 259.82, "sell" : 260.38,  "symbol" : "£"},
  "SEK" : {"15m" : 3182.51, "last" : 3182.51, "buy" : 3184.88, "sell" : 3191.81,  "symbol" : "kr"},
  "NZD" : {"15m" : 568.05, "last" : 568.05, "buy" : 568.47, "sell" : 569.71,  "symbol" : "$"},
  "BRL" : {"15m" : 1469.66, "last" : 1469.66, "buy" : 1470.75, "sell" : 1473.95,  "symbol" : "R$"},
  "RUB" : {"15m" : 29126.34, "last" : 29126.34, "buy" : 29148, "sell" : 29211.43,  "symbol" : "RUB"}

}

I would like to specifically capture the CAD buy value.

Currently I have a button and an EditText on my activity which performs calculations based on the value in EditText which is entered in manually by the user. I would like to extract the value from the api above so the user does not have to manually enter in that value.

Answer 1

Create a JSON object from your responce string from the api

JSONObject jsonObject = new JSONObject(response);

then get the CAD object from it

JSONObject jsonObjectCad = jsonObject.getJSONObject("CAD");
String buy = jsonObjectCad.getString("buy");

Answer 2

What you have is called a json string. You can use Jackson API to reflect this values into beans:

https://github.com/FasterXML/jackson

ObjectMapper mapper = new ObjectMapper();
String jsonInString = ""; // Your string from above.

User user = mapper.readValue(jsonInString, YourClass.class);

There are many examples on this topic in the web.