Convert string to JSON array

Question

I have the following string of a JSON from a web service and am trying to convert this to a JSONarray

{
 "locations": [
 {
 "lat": "23.053",
 "long": "72.629",
 "location": "ABC",
 "address": "DEF",
 "city": "Ahmedabad",
 "state": "Gujrat",
 "phonenumber": "1234567"
 },
 {
 "lat": "23.053",
 "long": "72.629",
 "location": "ABC",
 "address": "DEF",
 "city": "Ahmedabad",
 "state": "Gujrat",
 "phonenumber": "1234567"
 },
 {
 "lat": "23.053",
 "long": "72.629",
 "location": "ABC",
 "address": "DEF",
 "city": "Ahmedabad",
 "state": "Gujrat",
 "phonenumber": "1234567"
 },
 {
 "lat": "23.053",
 "long": "72.629",
 "location": "ABC",
 "address": "DEF",
 "city": "Ahmedabad",
 "state": "Gujrat",
 "phonenumber": "1234567"
 },
 {
 "lat": "23.053",
 "long": "72.629",
 "location": "ABC",
 "address": "DEF",
 "city": "Ahmedabad",
 "state": "Gujrat",
 "phonenumber": "1234567"
 }
 ]
}

I validated this String online, it seems to be correct. Now I am using the following code in android development to utilise

JSONArray jsonArray = new JSONArray(readlocationFeed);

This throws exception a type mismatch Exception.

• IgorGanapolsky: What data type is readlocationFeed?
• Andrew No: @IgorGanapolsky, String

Answer 1

Here you get JSONObject so change this line:

JSONArray jsonArray = new JSONArray(readlocationFeed); 

with following:

JSONObject jsnobject = new JSONObject(readlocationFeed);

and after

JSONArray jsonArray = jsnobject.getJSONArray("locations");
for (int i = 0; i < jsonArray.length(); i++) {
 JSONObject explrObject = jsonArray.getJSONObject(i);
}

• ankitkpd: noticed that constructor for JSONObject looks outdated and does not support String as a parameter in version 1.1.1
• DragonFire: jsnobject could be jsonobject - spelling :)

Answer 2

Input String

[
 {
 "userName": "sandeep",
 "age": 30
 }, 
 {
 "userName": "vivan",
 "age": 5
 }
]

Simple Way to Convert String to JSON

public class Test
{
 public static void main(String[] args) throws JSONException
 {
 String data = "[{\"userName\": \"sandeep\",\"age\":30},{\"userName\": \"vivan\",\"age\":5}] ";
 JSONArray jsonArr = new JSONArray(data);
 for (int i = 0; i < jsonArr.length(); i++)
 {
 JSONObject jsonObj = jsonArr.getJSONObject(i);
 System.out.println(jsonObj);
 }
 }
}

Output

{"userName":"sandeep","age":30}
{"userName":"vivan","age":5}

Answer 3

Using json lib:-

String data="[{"A":"a","B":"b","C":"c","D":"d","E":"e","F":"f","G":"g"}]";
Object object=null;
JSONArray arrayObj=null;
JSONParser jsonParser=new JSONParser();
object=jsonParser.parse(data);
arrayObj=(JSONArray) object;
System.out.println("Json object :: "+arrayObj);

Using GSON lib:-

Gson gson = new Gson();
String data="[{\"A\":\"a\",\"B\":\"b\",\"C\":\"c\",\"D\":\"d\",\"E\":\"e\",\"F\":\"f\",\"G\":\"g\"}]";
JsonParser jsonParser = new JsonParser();
JsonArray jsonArray = (JsonArray) jsonParser.parse(data);

• PAA: This will not be worked for Google GSON? Could you help for thhis?
• Aravind Cheekkallur: @pashtika.. please explain with your problem..then i can try for that.
• Aravind Cheekkallur: @pashtika ..yes you can use the GSON jar and convert your string into json
• Dev-iL: There seems to be a mistake in the 2nd code snippet, since the gson object is created but not used.
• fritz-playmaker: Just ignore the first line. It works with out it Gson gson = new Gson();

Answer 4

you will need to convert given string to JSONObject instead of JSONArray because current String contain JsonObject as root element instead of JsonArray :

JSONObject jsonObject = new JSONObject(readlocationFeed);

Answer 5

String b = "[" + readlocationFeed + "]";
JSONArray jsonArray1 = new JSONArray(b);
jsonarray_length1 = jsonArray1.length();
for (int i = 0; i < jsonarray_length1; i++) {
}

or convert it in JSONOBJECT

JSONObject jsonobj = new JSONObject(readlocationFeed);
JSONArray jsonArray = jsonobj.getJSONArray("locations");

• DragonFire: string manipulation is a great way of thinking from another direction - regarding this problem

Answer 6

Try this piece of code:

try { 
 Log.e("log_tag", "Error in convert String" + result.toString());
 JSONObject json_data = new JSONObject(result);
 String status = json_data.getString("Status");
 {
 String data = json_data.getString("locations");
 JSONArray json_data1 = new JSONArray(data);
 for (int i = 0; i < json_data1.length(); i++) {
 json_data = json_data1.getJSONObject(i);
 String lat = json_data.getString("lat");
 String lng = json_data.getString("long");
 }
 }
}

Answer 7

if the response is like this

"GetDataResult": "[{\"UserID\":1,\"DeviceID\":\"d1254\",\"MobileNO\":\"056688\",\"Pak1\":true,\"pak2\":true,\"pak3\":false,\"pak4\":true,\"pak5\":true,\"pak6\":false,\"pak7\":false,\"pak8\":true,\"pak9\":false,\"pak10\":true,\"pak11\":false,\"pak12\":false}]"

you can parse like this

JSONObject jobj=new JSONObject(response);
 String c = jobj.getString("GetDataResult"); 
 JSONArray jArray = new JSONArray(c);
 deviceId=jArray.getJSONObject(0).getString("DeviceID");

here the JsonArray size is 1.Otherwise you should use for loop for getting values.

Answer 8

It's a very simple way to convert:

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonParser;
class Usuario {
private String username;
private String email;
private Integer credits;
private String twitter_username;
public String getUsername() {
 return username;
}
public void setUsername(String username) {
 this.username = username;
}
public String getEmail() {
 return email;
}
public void setEmail(String email) {
 this.email = email;
}
public Integer getCredits() {
 return credits;
}
public void setCredits(Integer credits) {
 this.credits = credits;
}
public String getTwitter_username() {
 return twitter_username;
}
public void setTwitter_username(String twitter_username) {
 this.twitter_username = twitter_username;
}
@Override
public String toString() {
 return "UserName: " + this.getUsername() + " Email: " + this.getEmail();
}

}

/*
 * put string into file jsonFileArr.json
 * [{"username":"Hello","email":"[email protected]","credits"
 * :"100","twitter_username":""},
 * {"username":"Goodbye","email":"[email protected]"
 * ,"credits":"0","twitter_username":""},
 * {"username":"mlsilva","email":"[email protected]"
 * ,"credits":"524","twitter_username":""},
 * {"username":"fsouza","email":"[email protected]"
 * ,"credits":"1052","twitter_username":""}]
 */
public class TestaGsonLista {
public static void main(String[] args) {
 Gson gson = new Gson();
 try {
 BufferedReader br = new BufferedReader(new FileReader(
 "C:\\Temp\\jsonFileArr.json"));
 JsonArray jsonArray = new JsonParser().parse(br).getAsJsonArray();
 for (int i = 0; i < jsonArray.size(); i++) {
 JsonElement str = jsonArray.get(i);
 Usuario obj = gson.fromJson(str, Usuario.class);
 System.out.println(obj);
 System.out.println(str);
 System.out.println("-------");
 }
 } catch (IOException e) {
 e.printStackTrace();
 }
}

}

• Richard Erickson: Please improve you answer by adding context as text and not a comment.

Answer 9

You can do the following:

JSONArray jsonArray = jsnobject.getJSONArray("locations");
 for (int i = 0; i < jsonArray.length(); i++) {
 JSONObject explrObject = jsonArray.getJSONObject(i);
}

Answer 10

If using org.json.simple library to handle JSON in your project then -

String response = "[{\"UserID\":1,\"DeviceID\":\"d1254\",\"MobileNO\":\"056688\",\"Pak1\":true,\"pak2\":true,\"pak3\":false,\"pak4\":true,\"pak5\":true,\"pak6\":false,\"pak7\":false,\"pak8\":true,\"pak9\":false,\"pak10\":true,\"pak11\":false,\"pak12\":false}]";
 try {
 JSONArray responseArray = (JSONArray) new JSONParser().parse(response);
 // Do further processing/parsing of responseArray 
 } catch (ParseException | ClassCastException e) {
 // Handle JSON parsing exception
 System.out.println("Error parsing response JSON: " + e.getMessage());
 }

Answer 11

If having following JSON from web service, Json Array as a response :

 [3]
 0: {
 id: 2
 name: "a561137"
 password: "test"
 firstName: "abhishek"
 lastName: "ringsia"
 organization: "bbb"
 }-
1: {
 id: 3
 name: "a561023"
 password: "hello"
 firstName: "hello"
 lastName: "hello"
 organization: "hello"
 }-
 2: {
 id: 4
 name: "a541234"
 password: "hello"
 firstName: "hello"
 lastName: "hello"
 organization: "hello"
 }

have To Accept it first as a Json Array ,then while reading its Object have to use Object Mapper.readValue ,because Json Object Still in String .

 List<User> list = new ArrayList<User>();
 JSONArray jsonArr = new JSONArray(response);
 for (int i = 0; i < jsonArr.length(); i++) {
 JSONObject jsonObj = jsonArr.getJSONObject(i);
 ObjectMapper mapper = new ObjectMapper();
 User usr = mapper.readValue(jsonObj.toString(), User.class); 
 list.add(usr);
 }

mapper.read is correct function ,if u use mapper.convert(param,param) . It will give u error .