I have response body with type _JsonMap
How I can convert it into standard Json? I cannot find way to extract map with my data from this object
Dart has a built-in library called dart:convert which lets you convert data types.
You can use jsonDecode(String source) function to convert JSON strings to dart map
jsonDecode function
dynamic jsonDecode(
String source,
{Object? reviver(
Object? key,
Object? value
)?}
)
Parses the string and returns the resulting Json object.
import 'dart:convert';
...
final Map map = jsonDecode(response.body);
If you are trying to parse a JSON that is not in string format
you can just use
final Map map = Map.from(response.body);
final Map map = Map.from(response.body);
answer from #Terblanche Daniel
worked for me
Anybody has any idea how to parse below type of JSON object where same object named objects are present in master object. Below is an example
abc{
"abc":"123"
}
How to parse the child abc value?
You can use Json.NET it is vary easy to use. Json.NET handles JSON arrays natively, and will parse them into any type, string,int etc.
Are you currently using a JSON framework? Maybe check out Json.NET: http://www.newtonsoft.com/json.
Then you could do something like:
int onetwothree = jObject.SelectToken("abc.abc");
You can use http://www.newtonsoft.com/json to parse any json string on c#:
Your example :
var jsonString= "{\"abc\":{ \"abc\":\"123\" }}";
var jObj = JObject.Parse(jsonString);
var abcValue = jObj.SelectToken("abc.abc").Value<string>();
I need to pass an array of string/Int (doesnt matter) as JSON parameter in a HTTP body for a POST request.
{
"par1" : value,
"par2" : "value2",
"par3" : ['123:456', '123:234' ...]*
}
*My problem is for filling my JSON object with param3 values. In the swift code I have them as an array of Strings.
There are many example of converting a JSON object back to an array of strings/Int, but I can't find it the other way around.
As mentioned in the comments, the way to go is to use NSJSONSerialization to generate object encoded in JSON data.
I have the following string:
"{\"headers\":[\"CNPJ\",\"PDF\",\"error\"],\"rows\":[[\"17192451000170\",\"FILE:application/pdf;170286;\",null],[\"234566767544\",\"FILE:application/pdf;456378;\",null],[\"233456767544\",\"FILE:application/pdf;456378;\",null]]}"
how do I parse it to a normal Json format?
meaning:
{"rows" :[
{"CNPJ":"17192451000170","PDF":"FILE:application/pdf;170286;","error":null},
{"CNPJ":"17192451000170","PDF":"FILE:application/pdf;170286;","error":null},
{"CNPJ":"17192451000170", "PDF":"FILE:application/pdf;170286;,"error":null"}
]}
or any other json format
This is already a valid JSON format.
If you just want to strip \ then you can simply:
(hbd#crayon2.yoonka.com)31> JsonOrg = <<"{\"headers\":[\"CNPJ\",\"PDF\",\"error\"],\"rows\":[[\"17192451000170\",\"FILE:application/pdf;170286;\",null],[\"234566767544\",\"FILE:application/pdf;456378;\",null],[\"233456767544\",\"FILE:application/pdf;456378;\",null]]}">>.
<<"{\"headers\":[\"CNPJ\",\"PDF\",\"error\"],\"rows\":[[\"17192451000170\",\"FILE:application/pdf;170286;\",null],[\"234566767544\",\"FI"...>>
(hbd#crayon2.yoonka.com)32> io:format("~s~n", [binary_to_list(JsonOrg)]).
{"headers":["CNPJ","PDF","error"],"rows":[["17192451000170","FILE:application/pdf;170286;",null],["234566767544","FILE:application/pdf;456378;",null],["233456767544","FILE:application/pdf;456378;",null]]}
ok
You can also parse back and forth between Json and Erlang. I tested that with the yajler decoder:
(hbd#crayon2.yoonka.com)43> {ok, Parsed} = yajler:decode(<<"{\"headers\":[\"CNPJ\",\"PDF\",\"error\"],\"rows\":[[\"17192451000170\",\"FILE:application/pdf;170286;\",null],[\"234566767544\",\"FILE:application/pdf;456378;\",null],[\"233456767544\",\"FILE:application/pdf;456378;\",null]]}">>).
{ok,[{<<"headers">>,[<<"CNPJ">>,<<"PDF">>,<<"error">>]},
{<<"rows">>,
[[<<"17192451000170">>,<<"FILE:application/pdf;170286;">>,
undefined],
[<<"234566767544">>,<<"FILE:application/pdf;456378;">>,
undefined],
[<<"233456767544">>,<<"FILE:application/pdf;456378;">>,
undefined]]}]}
(hbd#crayon2.yoonka.com)44> Json = binary:list_to_bin(yajler:encode(Parsed)).
<<"{\"headers\":[\"CNPJ\",\"PDF\",\"error\"],\"rows\":[[\"17192451000170\",\"FILE:application/pdf;170286;\",\"undefined\"],[\"2345667675"...>>
Yajler is an Erlang NIF so it is using a C library, in this case called yajl, to do the actual parsing, but I imagine a similar result you would get from other Erlang applications that can parse JSON.
What is the fastest way to convert this
{"a":"ab","b":"cd","c":"cd","d":"de","e":"ef","f":"fg"}
into mutable map in scala ? I read this input string from ~500MB file. That is the reason I'm concerned about speed.
If your JSON is as simple as in your example, i.e. a sequence of key/value pairs, where each value is a string. You can do in plain Scala :
myString.substring(1, myString.length - 1)
.split(",")
.map(_.split(":"))
.map { case Array(k, v) => (k.substring(1, k.length-1), v.substring(1, v.length-1))}
.toMap
That looks like a JSON file, as Andrey says. You should consider this answer. It gives some example Scala code. Also, this answer gives some different JSON libraries and their relative merits.
The fastest way to read tree data structures in XML or JSON is by applying streaming API: Jackson Streaming API To Read And Write JSON.
Streaming would split your input into tokens like 'beginning of an object' or 'beginning of an array' and you would need to build a parser for these token, which in some cases is not a trivial task.
Keeping it simple. If reading a json string from file and converting to scala map
import spray.json._
import DefaultJsonProtocol._
val jsonStr = Source.fromFile(jsonFilePath).mkString
val jsonDoc=jsonStr.parseJson
val map_doc=jsonDoc.convertTo[Map[String, JsValue]]
// Get a Map key value
val key_value=map_doc.get("key").get.convertTo[String]
// If nested json, re-map it.
val key_map=map_doc.get("nested_key").get.convertTo[Map[String, JsValue]]
println("Nested Value " + key_map.get("key").get)