I have a Json Array as string without name and I want to parse it how can i do it in android ?
My array :
{"emp_info":[
{"id":"1","groupe":"1","professeur":"1"},
{"id":"2","groupe":"2","professeur":"1"}
]}
This is how you can parse it
Assuming your json string is data
JSONObject jsonObj = new JSONObject(data);
JSONArray empInfo = jsonObj.getJSONArray("emp_info");
for(int i = 0; i < empInfo.length(); i++){
JSONObject obj = empInfo.getJSONObject(i);
String id = obj.getString("id");
String groupe = obj.getString("groupe");
String professeur = obj.getString("professeur");
}
The example json you gave has a name, but if it doesn't this is how I do it. Using Gson to parse JSON, I use TypeToken to tell the gson builder it's an array.
List<MyObject> jsonObject = new Gson().fromJson(json, new TypeToken<List<MyObject>>().getType());
With the following code you'll have an object representation of your json array.
Related
I use javax to create JsonObject and JsonArray from my List<String> and I have a list of Json objects that i want to put in a JsonObject through a JsonArray
JsonArrayBuilder jsonArray = Json.createArrayBuilder();
for (String Obj : listOfJsonDfObjects)
jsonArray.add(summaryObj); //{"a":"b"},{"c":"d"}
// this line introduces extra escaping quotes like this {"\"a\"":"\"b\""},{"\"c\"":"\"d\""}
javax.json.JsonObject data = Json.createObjectBuilder()
.add("data", jsonArray.build()).build();
How to avoid these extra quotes escaping characters?
Thanks
You say you have a list of JSON objects, but you really have a list of JSON-formatted strings. To add them to a JsonArray, you need to parse each one into the JSON object model:
public class JsonTest {
public static void main(String[] args) {
List<String> listOfJsonDfObjects = List.of(
"{\"a\":\"b\"}",
"{\"c\":\"d\"}"
);
JsonArrayBuilder jsonArray = Json.createArrayBuilder();
for (String summaryObj : listOfJsonDfObjects) {
JsonReader parser = Json.createReader(new StringReader(summaryObj));
jsonArray.add(parser.readObject());
}
JsonObject data = Json.createObjectBuilder()
.add("data", jsonArray.build()).build();
System.out.println(data); // {"data":[{"a":"b"},{"c":"d"}]}
}
}
Using Gson
Gson gson = new Gson();
String json = gson.toJson(listOfJsonDfObjects);
//check json
System.out.println(json);
json = json.replaceAll("\\\\", "");
json = json.replaceAll("\"\\{", "{");
json = json.replaceAll("\\}\"", "}");
//valid json now
System.out.println(json);
A more secure way (to avoid altering original data)
//concatenate objects in list with comma
String json = String.join(",", listOfJsonDfObjects);
//convert to pseudo array
json = "[" + json + "]";
//convert pseudo json array to pseudo json object
json = "{\"data\":" + json + "}";
//cast to json object
JsonObject jsonObject = new Gson().fromJson(json, JsonObject.class);
System.out.println(jsonObject);
I have this json in java:
jsonObj = {"ps":["2.16.840.1.113883.6.1","LOINC","2.34"]}
jsonObj is response from an API, so I have it as jsonObject and I don't read it from any file.
Is there an easy way to extract all the values as individuals like jsonObj [1]?
You may Use Gson parsing library as below :
Gson gson = new Gson();
// 1. JSON to Java object, read it from a file.
Staff staff = gson.fromJson(new FileReader("D:\\file.json"), Staff.class);
// 2. JSON to Java object, read it from a Json String.
String jsonInString = "{'name' : 'mkyong'}";
Staff staff = gson.fromJson(jsonInString, Staff.class);
// JSON to JsonElement, convert to String later.
JsonElement json = gson.fromJson(new FileReader("D:\\file.json"), JsonElement.class);
String result = gson.toJson(json);
Gson gson = new Gson();
String jsonInString = "{\"userId\":\"1\",\"userName\":\"Yasir\"}";
User user= gson.fromJson(jsonInString, User.class);
or simply use:
example
JSONObject object = new JSONObject(your_json_response_string);
String IMEICheckResponse = object.getString("getIMEIResult");
for Array use :
//getting whole json string
JSONObject jsonObj = new JSONObject(jsonStr);
//extracting data array from json string
JSONArray ja_data = jsonObj.getJSONArray("data");
int length = jsonObj .length();
You should use a library to deserialize your JSON in a Java Object.
Libraries like GSON, Genson or Jackson.
Once you transform the json in a object, it will have a property called "ps" that will be an array (or a List)
So I have some code that is able to send this out:
{"id":1,
"method":"addWaypoint",
"jsonrpc":"2.0",
"params":[
{
"lon":2,
"name":"name",
"lat":1,
"ele":3
}
]
}
The server receives this JSON object as a string named "clientstring":
JSONObject obj = new JSONObject(clientstring); //Make string a JSONObject
String method = obj.getString("method"); //Pulls out the corresponding method
Now, I want to be able to get the "params" value of {"lon":2,"name":"name","lat":1,"ele":3} just like how I got the "method".
however both of these have given me exceptions:
String params = obj.getString("params");
and
JSONObject params = obj.getJSONObject("params");
I'm really at a loss how I can store and use {"lon":2,"name":"name","lat":1,"ele":3} without getting an exception, it's legal JSON yet it can't be stored as an JSONObject? I dont understand.
Any help is VERY appreciated, thanks!
params in your case is not a JSONObject, but it is a JSONArray.
So all you need to do is first fetch the JSONArray and then fetch the first element of that array as the JSONObject.
JSONObject obj = new JSONObject(clientstring);
JSONArray params = obj.getJsonArray("params");
JSONObject param1 = params.getJsonObject(0);
How try like that
JSONObject obj = new JSONObject(clientstring);
JSONArray paramsArr = obj.getJSONArray("params");
JSONObject param1 = paramsArr.getJSONObject(0);
//now get required values by key
System.out.println(param1.getInt("lon"));
System.out.println(param1.getString("name"));
System.out.println(param1.getInt("lat"));
System.out.println(param1.getInt("ele"));
Here "params" is not an object but an array. So you have to parse using:
JSONArray jsondata = obj.getJSONArray("params");
for (int j = 0; j < jsondata.length(); j++) {
JSONObject obj1 = jsondata.getJSONObject(j);
String longitude = obj1.getString("lon");
String name = obj1.getString("name");
String latitude = obj1.getString("lat");
String element = obj1.getString("ele");
}
I'm very new to parsing JSON. I have looked all over and cannot seem to grasp the idea to my particular problem. I'm having a hard time understanding how to get a JSON object from a JSON array. My example is below
[{"styleId":94,
"status":"verified",
"abv":"4.2",
"name":"Bud Light"}]
Here is my current code
JSONParser parser = new JSONParser();
Object obj = parser.parse(inputLine);
JSONObject jsonObject = (JSONObject) obj;
Long currPage = (Long)jsonObject.get("currentPage");
System.out.println(currPage);
JSONArray jArray = (JSONArray)jsonObject.get("data");
System.out.println(jArray);
inputLine is my orignal JSON. I have pulled a JSONArray out of the original JSONObject that has the "data" tag. Now this is where I'm stuck and given the JSONArray at the top. Not sure how to iterate through the Array to grab JUST the "name" tag.
Thanks for the help in advanced!
To iterate in a JSONArray you need to go through each element in a loop.
int resultSize = jArray.length();
JSONObject result;
for (int i = 0; i < resultSize; i++) {
result = resultsArray.getJSONObject(i);
String name = result.getString("name");
// do whatever you want to do now...
}
just use Gson . it works well out of the box with any object type you supply.
This is an example from the user's guide:
int[] ints2 = gson.fromJson("[1,2,3,4,5]", int[].class);
How can I create a JSONArray, since creating a JSONObject is quite simple:
JSONObject j = new JSONObject();
j.put("key",value);
Right now I can put another string in the JSONObject, or a string representation of a JSONObject.
But how can I create a JSONArray and insert it to the JSONObject?
But how can I create a JSONArray and insert it to the JSONObject?
You can create JSONArray same like you have tried to create JSONObject.
Creating time:
For example:
JSONArray myArray = new JSONArray();
JSONObject j = new JSONObject();
j.put("key",value);
j.put("array",myArray);
Retrieving time:
you can fetch the value of String or JSONObject or any by their key name. For example:
JSONArray myArray = objJson.getJSONArray("array");
You can do it like:
String[] data = {"stringone", "stringtwo"};
JSONArray json = new JSONArray(Arrays.toString(data));
Or, create a JSONArray object and use the put method(s) to add any Strings you want. To output the result, just use the toString() method.
Why dont you use Gson library its very easy to convert any object into json array, json object
Download Gson library then use like
Gson gson=new Gson();
String json=gson.toJson(object);
if Object is of List object it will create json array
Gson gson = new Gson();
reverse parsing for array --
listObject = gson.fromJson(json,
new TypeToken<List<ClassName>>() {
}.getType());
for single object
object = gson.fromJson(json, ClassName.class);