CODEWITHSUNDEEP
androidandroid-listview
TheGeekNess
TheGeekNess

Reputation: 1647

Converting JSONarray to ArrayList

I am downloading a JSON string and converting it to JSONArray. Im putting it into a listview and need to be able to delete from that listview later, and since JSONArray has no .remove method (Thanks Obama), I am trying to convert it to an arraylist.

here is my JSON (the array.toString()):

[
    {
         "thumb_url":"tb1370913834.jpg",
         "event_id":"15","count":"44",
         "event_tagline":"this is a tagline",
         "event_name":"5th birthday",
         "event_end":"1370919600",
         "event_start":"1370876400"
    }
]

I need to get it into an array and be able to call the strings by their respective keys. Appreciate any help!

Upvotes: 143

Views: 471821

Answers (24)

hello java
hello java

Reputation: 1

`JSONArray data = root.getJSONArray("data");

    ObjectMapper mapper = new ObjectMapper();

List list = mapper.readValue(data.toString(), new TypeReference<>() { })`

Upvotes: 0

Hiren Patel
Hiren Patel

Reputation: 52810

I've done it using Gson (by Google).

Add the following line to your module's build.gradle:

dependencies {
  // ...
  // Note that `compile` will be deprecated. Use `implementation` instead.
  // See https://stackoverflow.com/a/44409111 for more info
  implementation 'com.google.code.gson:gson:2.8.2'
}

JSON string:

private String jsonString = "[\n" +
            "        {\n" +
            "                \"id\": \"c200\",\n" +
            "                \"name\": \"Ravi Tamada\",\n" +
            "                \"email\": \"[email protected]\",\n" +
            "                \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
            "                \"gender\" : \"male\",\n" +
            "                \"phone\": {\n" +
            "                    \"mobile\": \"+91 0000000000\",\n" +
            "                    \"home\": \"00 000000\",\n" +
            "                    \"office\": \"00 000000\"\n" +
            "                }\n" +
            "        },\n" +
            "        {\n" +
            "                \"id\": \"c201\",\n" +
            "                \"name\": \"Johnny Depp\",\n" +
            "                \"email\": \"[email protected]\",\n" +
            "                \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
            "                \"gender\" : \"male\",\n" +
            "                \"phone\": {\n" +
            "                    \"mobile\": \"+91 0000000000\",\n" +
            "                    \"home\": \"00 000000\",\n" +
            "                    \"office\": \"00 000000\"\n" +
            "                }\n" +
            "        },\n" +
            "        {\n" +
            "                \"id\": \"c202\",\n" +
            "                \"name\": \"Leonardo Dicaprio\",\n" +
            "                \"email\": \"[email protected]\",\n" +
            "                \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
            "                \"gender\" : \"male\",\n" +
            "                \"phone\": {\n" +
            "                    \"mobile\": \"+91 0000000000\",\n" +
            "                    \"home\": \"00 000000\",\n" +
            "                    \"office\": \"00 000000\"\n" +
            "                }\n" +
            "        },\n" +
            "        {\n" +
            "                \"id\": \"c203\",\n" +
            "                \"name\": \"John Wayne\",\n" +
            "                \"email\": \"[email protected]\",\n" +
            "                \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
            "                \"gender\" : \"male\",\n" +
            "                \"phone\": {\n" +
            "                    \"mobile\": \"+91 0000000000\",\n" +
            "                    \"home\": \"00 000000\",\n" +
            "                    \"office\": \"00 000000\"\n" +
            "                }\n" +
            "        },\n" +
            "        {\n" +
            "                \"id\": \"c204\",\n" +
            "                \"name\": \"Angelina Jolie\",\n" +
            "                \"email\": \"[email protected]\",\n" +
            "                \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
            "                \"gender\" : \"female\",\n" +
            "                \"phone\": {\n" +
            "                    \"mobile\": \"+91 0000000000\",\n" +
            "                    \"home\": \"00 000000\",\n" +
            "                    \"office\": \"00 000000\"\n" +
            "                }\n" +
            "        },\n" +
            "        {\n" +
            "                \"id\": \"c205\",\n" +
            "                \"name\": \"Dido\",\n" +
            "                \"email\": \"[email protected]\",\n" +
            "                \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
            "                \"gender\" : \"female\",\n" +
            "                \"phone\": {\n" +
            "                    \"mobile\": \"+91 0000000000\",\n" +
            "                    \"home\": \"00 000000\",\n" +
            "                    \"office\": \"00 000000\"\n" +
            "                }\n" +
            "        },\n" +
            "        {\n" +
            "                \"id\": \"c206\",\n" +
            "                \"name\": \"Adele\",\n" +
            "                \"email\": \"[email protected]\",\n" +
            "                \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
            "                \"gender\" : \"female\",\n" +
            "                \"phone\": {\n" +
            "                    \"mobile\": \"+91 0000000000\",\n" +
            "                    \"home\": \"00 000000\",\n" +
            "                    \"office\": \"00 000000\"\n" +
            "                }\n" +
            "        },\n" +
            "        {\n" +
            "                \"id\": \"c207\",\n" +
            "                \"name\": \"Hugh Jackman\",\n" +
            "                \"email\": \"[email protected]\",\n" +
            "                \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
            "                \"gender\" : \"male\",\n" +
            "                \"phone\": {\n" +
            "                    \"mobile\": \"+91 0000000000\",\n" +
            "                    \"home\": \"00 000000\",\n" +
            "                    \"office\": \"00 000000\"\n" +
            "                }\n" +
            "        },\n" +
            "        {\n" +
            "                \"id\": \"c208\",\n" +
            "                \"name\": \"Will Smith\",\n" +
            "                \"email\": \"[email protected]\",\n" +
            "                \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
            "                \"gender\" : \"male\",\n" +
            "                \"phone\": {\n" +
            "                    \"mobile\": \"+91 0000000000\",\n" +
            "                    \"home\": \"00 000000\",\n" +
            "                    \"office\": \"00 000000\"\n" +
            "                }\n" +
            "        },\n" +
            "        {\n" +
            "                \"id\": \"c209\",\n" +
            "                \"name\": \"Clint Eastwood\",\n" +
            "                \"email\": \"[email protected]\",\n" +
            "                \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
            "                \"gender\" : \"male\",\n" +
            "                \"phone\": {\n" +
            "                    \"mobile\": \"+91 0000000000\",\n" +
            "                    \"home\": \"00 000000\",\n" +
            "                    \"office\": \"00 000000\"\n" +
            "                }\n" +
            "        },\n" +
            "        {\n" +
            "                \"id\": \"c2010\",\n" +
            "                \"name\": \"Barack Obama\",\n" +
            "                \"email\": \"[email protected]\",\n" +
            "                \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
            "                \"gender\" : \"male\",\n" +
            "                \"phone\": {\n" +
            "                    \"mobile\": \"+91 0000000000\",\n" +
            "                    \"home\": \"00 000000\",\n" +
            "                    \"office\": \"00 000000\"\n" +
            "                }\n" +
            "        },\n" +
            "        {\n" +
            "                \"id\": \"c2011\",\n" +
            "                \"name\": \"Kate Winslet\",\n" +
            "                \"email\": \"[email protected]\",\n" +
            "                \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
            "                \"gender\" : \"female\",\n" +
            "                \"phone\": {\n" +
            "                    \"mobile\": \"+91 0000000000\",\n" +
            "                    \"home\": \"00 000000\",\n" +
            "                    \"office\": \"00 000000\"\n" +
            "                }\n" +
            "        },\n" +
            "        {\n" +
            "                \"id\": \"c2012\",\n" +
            "                \"name\": \"Eminem\",\n" +
            "                \"email\": \"[email protected]\",\n" +
            "                \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
            "                \"gender\" : \"male\",\n" +
            "                \"phone\": {\n" +
            "                    \"mobile\": \"+91 0000000000\",\n" +
            "                    \"home\": \"00 000000\",\n" +
            "                    \"office\": \"00 000000\"\n" +
            "                }\n" +
            "        }\n" +
            "    ]";

ContactModel.java:

public class ContactModel {
     public String id;
     public String name;
     public String email;
}

Code for converting a JSON string to ArrayList<Model>:

Note: You have to import java.lang.reflect.Type;:

// Top of file
import java.lang.reflect.Type;

// ...

private void parseJSON() {
    Gson gson = new Gson();
    Type type = new TypeToken<List<ContactModel>>(){}.getType();
    List<ContactModel> contactList = gson.fromJson(jsonString, type);
    for (ContactModel contact : contactList){
        Log.i("Contact Details", contact.id + "-" + contact.name + "-" + contact.email);
    }
}

Hope this will help you.

Upvotes: 85

Dut A.
Dut A.

Reputation: 1178

This can do (Java >= 8):

    // Functional (variable)
    Function<JSONArray, ArrayList<String>> convert = jsonArray -> (ArrayList<String>) jsonArray.stream()
        .map(item -> item.toString())
        .collect(Collectors.toList());

    // Call
    convert.apply(jsonArray);


    // Regular method (OOP)
    private Function<JSONArray, ArrayList<String>> convert() {
        return jsonArray -> (ArrayList<String>) jsonArray.stream()
            .map(item -> item.toString())
            .collect(Collectors.toList());
   }

   // Call
   convert().apply(jsonArray);

Upvotes: 0

Anant Simran Singh
Anant Simran Singh

Reputation: 637

In Java 8,

IntStream.range(0,jsonArray.length()).mapToObj(i->jsonArray.getString(i)).collect(Collectors.toList())

Upvotes: 8

avisper
avisper

Reputation: 908

with GSON and Kotlin you just need this:

    val arr = Gson().fromJson(jsonArrayInString, Array<T>::class.java)

Upvotes: 2

Ashwani Sharma
Ashwani Sharma

Reputation: 499

Single line code that I used to convert json array to ArrayList for the below listed json string stored in a variable named classData.

List<String> names = new Gson().fromJson(classData.getAsJsonObject("result").getAsJsonArray("names").toString(), new TypeToken<List<String>>(){}.getType());

{   
    "result": {
        "id": "104297",
        "class": "Chemistry",
        "total": 57,
        "names": [
            "Alex",
            "Dan",
            "Rex",
            "Tony",
            "Elizabeth"
        ],
        ...
    }
}

Upvotes: 1

HIMANSHU GOYAL
HIMANSHU GOYAL

Reputation: 481

If the Json object consists an array of strings, then there is a way where we need not even use the JSONArray.

if the Json is not in string format, we can convert the json into a string. Now if Json string is:

String value = "[\"value1\",\"value2\"]";

Then we can use to get the List of String:

List<String> result = new Gson().fromJson(value, List.class);

Upvotes: 2

aianitro
aianitro

Reputation: 886

public static List<String> convertJsonArrayToStringList(JsonArray ja){
    
    List<String> result = new ArrayList<String>();     
    for(JsonElement je: ja)
        result.add(je.getAsString());
    
    return result;
    
}

Upvotes: 0

Phoenix87
Phoenix87

Reputation: 1149

With Kotlin, you can avoid a loop by wrapping the JSONArray with a MutableList, e.g.

val artistMetadata = player.metadata.optJSONArray("artist")
val artists = MutableList<String>(artistMetadata.length()) { i -> artistMetadata.getString(i)}

Upvotes: 1

Vivek Dhayaal
Vivek Dhayaal

Reputation: 1

A simpler Java 8 alternative:

JSONArray data = new JSONArray(); //create data from this -> [{"thumb_url":"tb-1370913834.jpg","event_id":...}]

List<JSONObject> list = data.stream().map(o -> (JSONObject) o).collect(Collectors.toList());

Upvotes: 0

Min Hyoung Hong
Min Hyoung Hong

Reputation: 1202

Java 8 style

   JSONArray data = jsonObject.getJSONArray("some-node");

   List<JSONObject> list = StreamSupport.stream(data.spliterator(), false)
                .map(e -> (JSONObject)e)
                .collect(Collectors.toList());

Upvotes: 1

Prem Abhisek
Prem Abhisek

Reputation: 31

Just going by the original subject of the thread:

converting jsonarray to list (used jackson jsonarray and object mapper here):

ObjectMapper mapper = new ObjectMapper();
JSONArray array = new JSONArray();
array.put("IND");
array.put("CHN");
List<String> list = mapper.readValue(array.toString(), List.class);

Upvotes: 2

naveen sunkavalli
naveen sunkavalli

Reputation: 1

ArrayList<String> listdata = new ArrayList<String>();     
JSONArray jArray = (JSONArray)jsonObject; 
if (jArray != null) { 
 listdata.addAll(jArray);
}

@simplified

Upvotes: 0

Mehul Boghra
Mehul Boghra

Reputation: 232

if you want to extract data form JSON string array, here is my working code. change parameter as your data.

PoJo class

public class AllAppModel {
    private String appName;
    private String packageName;
    private int uid;
    private boolean isSelected;
    private boolean isSystemApp;
    private boolean isFav;
}

Extract your data using below line of code

try {
    JSONArray jsonArr = new JSONArray("Your json string array");
    List<AllAppModel> lstExtrextData = new ArrayList<>();
    for (int i = 0; i < jsonArr.length(); i++) {
        JSONObject jsonObj = jsonArr.getJSONObject(i);
        AllAppModel data = new AllAppModel();
        data.setAppName(jsonObj.getString("appName"));
        data.setPackageName(jsonObj.getString("packageName"));
        data.setUid(jsonObj.getInt("uid"));
        data.setSelected(jsonObj.getBoolean("isSelected"));
        data.setSystemApp(jsonObj.getBoolean("isSystemApp"));
        data.setFav(jsonObj.getBoolean("isFav"));
        lstExtrextData.add(data);
    }
} catch (JSONException e) {
    e.printStackTrace();
}

it will return you List of PoJo class object.

Upvotes: 2

yoAlex5
yoAlex5

Reputation: 34451

Generic variant

public static <T> List<T> getList(JSONArray jsonArray) throws Exception {

    List<T> list = new ArrayList<>(jsonArray.length());

    for (int i = 0; i < jsonArray.length(); i++) {

        list.add((T)jsonArray.get(i));
    }

    return list;

}

//Usage

List<String> listKeyString = getList(dataJsonObject.getJSONArray("keyString"));

Upvotes: 0

kunal khedkar
kunal khedkar

Reputation: 947

Using Gson

    List<Student> students = new ArrayList<>();
    JSONArray jsonArray = new JSONArray(stringJsonContainArray);
    for (int i = 0; i < jsonArray.length(); i++) {
        Student student = new Gson().fromJson(jsonArray.get(i).toString(), Student.class);
        students.add(student);
    }
    return students;

Upvotes: 1

Bheem Singh
Bheem Singh

Reputation: 707

I have fast solution. Just create a file ArrayUtil.java

ObjectMapper mapper = new ObjectMapper(); 
List<Student> list = Arrays.asList(mapper.readValue(jsonString, Student[].class));

Usage:

ArrayList<Object> list = ArrayUtil.convert(jArray);

or

JSONArray jArr = ArrayUtil.convert(list);

Upvotes: 3

Vasilii Suricov
Vasilii Suricov

Reputation: 954

I have fast solution. Just create a file ArrayUtil.java

import java.util.ArrayList;
import java.util.Collection;
import org.json.JSONArray;
import org.json.JSONException;

public class ArrayUtil
{
    public static ArrayList<Object> convert(JSONArray jArr)
    {
        ArrayList<Object> list = new ArrayList<Object>();
        try {
            for (int i=0, l=jArr.length(); i<l; i++){
                 list.add(jArr.get(i));
            }
        } catch (JSONException e) {}

        return list;
    }

    public static JSONArray convert(Collection<Object> list)
    {
        return new JSONArray(list);
    }

}

Usage:

ArrayList<Object> list = ArrayUtil.convert(jArray);

or

JSONArray jArr = ArrayUtil.convert(list);

Upvotes: 8

Sagar Maiyad
Sagar Maiyad

Reputation: 12753

ArrayList<String> listdata = new ArrayList<String>();     
JSONArray jArray = (JSONArray)jsonObject; 
if (jArray != null) { 
   for (int i=0;i<jArray.length();i++){ 
    listdata.add(jArray.getString(i));
   } 
}

Upvotes: 204

ceph3us
ceph3us

Reputation: 7484

public static List<JSONObject> getJSONObjectListFromJSONArray(JSONArray array) 
        throws JSONException {
  ArrayList<JSONObject> jsonObjects = new ArrayList<>();
  for (int i = 0; 
           i < (array != null ? array.length() : 0);           
           jsonObjects.add(array.getJSONObject(i++))
       );
  return jsonObjects;
}

Upvotes: 0

Sorter
Sorter

Reputation: 10240

 JSONArray array = new JSONArray(json);
 List<JSONObject> list = new ArrayList();
 for (int i = 0; i < array.length();list.add(array.getJSONObject(i++)));

Upvotes: 4

R9J
R9J

Reputation: 6715

To make it handy, use POJO.

try like this..

List<YourPojoObject> yourPojos = new ArrayList<YourPojoObject>();

JSONObject jsonObject = new JSONObject(jsonString);
YourPojoObject yourPojo = new YourPojoObject();
yourPojo.setId(jsonObject.getString("idName"));
...
...

yourPojos.add(yourPojo);

Upvotes: 2

brianestey
brianestey

Reputation: 8302

Instead of converting the JSON string to an ArrayList or even a Map, you can just create a JSONObject itself. This object has the ability to get string values by key, as you want and also to remove objects.

To create a JSONObject from a properly formatted JSON string, you simply call the appropriate constructor.

JSONObject json = new JSONObject(jsonString);

Upvotes: 7

Sunil Kumar
Sunil Kumar

Reputation: 7082

try this way Simply loop through that, building your own array. This code assumes it's an array of strings, it shouldn't be hard to modify to suit your particular array structure.

JSONArray jsonArray = new JSONArray(jsonArrayString);
List<String> list = new ArrayList<String>();
for (int i=0; i<jsonArray.length(); i++) {
    list.add( jsonArray.getString(i) );

Upvotes: 7

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