If I read the JSONArray constructors correctly, you can build them from any Collection (arrayList is a subclass of Collection) like so:
ArrayList<String> list = new ArrayList<String>();
list.add("foo");
list.add("baar");
JSONArray jsArray = new JSONArray(list);
References:
- jsonarray constructor: http://developer.android.com/reference/org/json/JSONArray.html#JSONArray%28java.util.Collection%29
- collection: http://developer.android.com/reference/java/util/Collection.html
TutorialsPoint
tutorialspoint.com › article › how-to-convert-java-array-or-arraylist-to-jsonarray-using-gson-in-java
How to convert Java array or ArrayList to JsonArray using Gson in Java?
July 8, 2020 - import com.google.gson.*; import java.util.*; public class JavaArrayToJsonArrayTest { public static void main(String args[]) { String[][] strArray = {{"elem1-1", "elem1-2"}, {"elem2-1", "elem2-2"}}; ArrayList<ArrayList<String>> arrayList = new ArrayList<>(); for(int i = 0; i < strArray.length; i++) { ArrayList<String> nextElement = new ArrayList<>(); for(int j = 0; j < strArray[i].length; j++) { nextElement.add(strArray[i][j] + "-B"); } arrayList.add(nextElement); } JsonObject jsonObj = new JsonObject(); // array to JsonArray JsonArray jsonArray1 = new Gson().toJsonTree(strArray).getAsJsonArray(); // ArrayList to JsonArray JsonArray jsonArray2 = new Gson().toJsonTree(arrayList).getAsJsonArray(); jsonObj.add("jsonArray1", jsonArray1); jsonObj.add("jsonArray2", jsonArray2); System.out.println(jsonObj.toString()); } }
Baeldung
baeldung.com › home › java › java list › converting a java list to a json array
Converting a Java List to a Json Array | Baeldung
June 18, 2025 - In addition to external libraries like Gson and Jackson, Java also provides a built-in library called org.json for JSON processing. To convert a Java List to a JSON array using org.json, we can use the JSONArray class to accomplish this task.
17:31
Parse JSON to Java Object,ArrayList & Array Using Jackson Library ...
14:17
40. Convert JSON Array API Response to Java List to extract values ...
04:48
Java json 01 create an arraylist to serialize with Jackson library ...
08:28
Rest Service To Handle Json List Input As ArrayList - YouTube
15:24
How to Convert Java Objects to JSON - YouTube
Top answer 1 of 9
138
If I read the JSONArray constructors correctly, you can build them from any Collection (arrayList is a subclass of Collection) like so:
ArrayList<String> list = new ArrayList<String>();
list.add("foo");
list.add("baar");
JSONArray jsArray = new JSONArray(list);
References:
- jsonarray constructor: http://developer.android.com/reference/org/json/JSONArray.html#JSONArray%28java.util.Collection%29
- collection: http://developer.android.com/reference/java/util/Collection.html
2 of 9
77
Use Gson library to convert ArrayList to JsonArray.
Gson gson = new GsonBuilder().create();
JsonArray myCustomArray = gson.toJsonTree(myCustomList).getAsJsonArray();
GeeksforGeeks
geeksforgeeks.org › java › how-to-convert-an-arraylist-of-objects-to-a-json-array-in-java
How to Convert an ArrayList of Objects to a JSON Array in Java? - GeeksforGeeks
July 23, 2025 - In the above code, a Java class called Course models the properties of a course like its id, name, fees, and duration. It has getter and setter methods to access and modify the private fields. Here we are adding the logic of converting an ArrayList of objects to a JSON array of Java in the main class.
TutorialsPoint
tutorialspoint.com › how-can-we-convert-a-list-to-the-json-array-in-java
How to convert a List to JSON array using the Jackson library in Java?
April 22, 2025 - import java.util.*; import com.fasterxml.jackson.databind.*; import com.fasterxml.jackson.databind.node.ArrayNode; public class ListToJSONArrayUsingArrayNode { public static void main(String[] args) { List < String > list = Arrays.asList("JAVA", "PYTHON", "SCALA", ".NET", "TESTING"); ObjectMapper objectMapper = new ObjectMapper(); ArrayNode arrayNode = objectMapper.createArrayNode(); for (String item: list) { arrayNode.add(item); // adding each item manually } try { String jsonArray = objectMapper.writeValueAsString(arrayNode); System.out.println(jsonArray); } catch (Exception e) { e.printStackTrace(); } } }
GitHub
gist.github.com › 21ec4a3a1fe9dc52e2cd195479428f98
JAVA array or ArrayList to JsonArray (Gson) · GitHub
JAVA array or ArrayList to JsonArray (Gson). GitHub Gist: instantly share code, notes, and snippets.
Crunchify
crunchify.com › json tutorials › in java how to convert arraylist to jsonobject?
In Java How to Convert ArrayList to JSONObject? • Crunchify
May 17, 2018 - package crunchify.com.tutorial; import java.util.ArrayList; import com.google.gson.Gson; import com.google.gson.GsonBuilder; /** * @author Crunchify.com * Program: Best way to convert Java ArrayList to JSONObject * Version: 1.0.0 * */ public class CrunchifyArrayListToJsonObject { public static void main(String a[]) { ArrayList<String> crunchify = new ArrayList<String>(); crunchify.add("Google"); crunchify.add("Facebook"); crunchify.add("Crunchify"); crunchify.add("Twitter"); crunchify.add("Snapchat"); crunchify.add("Microsoft"); log("Raw ArrayList ===> " + crunchify); // Use this builder to construct a Gson instance when you need to set configuration options other than the default.
BeginnersBook
beginnersbook.com › 2024 › 06 › convert-json-array-to-arraylist-in-java
Convert JSON Array to ArrayList in Java
June 13, 2024 - The object of JSONArray is created by passing jsonArrayString in the constructor of JSONArray class. The ArrayList that we have created is of JSONObject type, each element of this ArrayList represents the element of JSONArray.
Top answer 1 of 6
45
Below code should work for your case.
List<Customer> customerList = CustomerDB.selectAll();
Gson gson = new Gson();
JsonElement element = gson.toJsonTree(customerList, new TypeToken<List<Customer>>() {}.getType());
if (! element.isJsonArray() ) {
// fail appropriately
throw new SomeException();
}
JsonArray jsonArray = element.getAsJsonArray();
Heck, use List interface to collect values before converting it JSON Tree.
2 of 6
14
As an additional answer, it can also be made shorter.
List<Customer> customerList = CustomerDB.selectAll();
JsonArray result = (JsonArray) new Gson().toJsonTree(customerList,
new TypeToken<List<Customer>>() {
}.getType());
Top answer 1 of 8
117
If you want or need to work with a Java array then you can always use the java.util.Arrays utility classes' static asList() method to convert your array to a List.
Something along those lines should work.
String mStringArray[] = { "String1", "String2" };
JSONArray mJSONArray = new JSONArray(Arrays.asList(mStringArray));
Beware that code is written offhand so consider it pseudo-code.
2 of 8
40
ArrayList<String> list = new ArrayList<String>();
list.add("blah");
list.add("bleh");
JSONArray jsArray = new JSONArray(list);
This is only an example using a string arraylist
Top answer 1 of 16
204
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));
}
}
2 of 16
85
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\": \"ravi@gmail.com\",\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\": \"johnny_depp@gmail.com\",\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\": \"leonardo_dicaprio@gmail.com\",\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\": \"john_wayne@gmail.com\",\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\": \"angelina_jolie@gmail.com\",\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\": \"dido@gmail.com\",\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\": \"adele@gmail.com\",\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\": \"hugh_jackman@gmail.com\",\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\": \"will_smith@gmail.com\",\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\": \"clint_eastwood@gmail.com\",\n" +
" \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
" \"gender\" : \"male\",\n" +
" \"phone\": {\n" +
" \"mobile\": \"+91 0000000000\",Java Guides
javaguides.net › 2019 › 07 › convert-list-to-json-array-using-jackson.html
Convert List to JSON Array Using Jackson
July 21, 2019 - In this quick article, I will show how to convert a List to JSON array using Jackson. Check out complete Jackson tutorial at Java Jackson JSON Tutorial with Examples. We are using Jackson library to convert Java List to JSON array so let's add below Jackson dependency to your project's classpath ...
YouTube
youtube.com › watch
Java JSON Array Encode Using ArrayList - YouTube
#JavaJSONArray #HomeStay #StaySafe #ArrayList #JSONArrayListJava JSON ArrayList Encode0:05 JSON Install1:53 JSON Array Example Start time:Like, Share, And Su...
Published: April 7, 2020
Top answer 1 of 4
2
Shouldn't it be something like this?
JSONArray ar = new JSONArray();
for (int i = 0; i < objectList.size(); i++) {
JSONObject objects = new JSONObject();
objects.put("a", objectlist.get(i).getA();
objects.put("b", objectlist.get(i).getB();
ar.put(objects);
}
jOuter.put("s",ar);
2 of 4
2
Your s entry is actually a JsonArray, while your p is just a property. Here I am using Gson but you could easily apply it to whichever library you are using. So you can do the following:
JsonObject jObj = new JsonObject();
jObj.addProperty("p", 1);
JsonArray sArr = new JsonArray();
for (int i = 0; i < objectList.size(); i++)
{
JsonObject innerObj = new JsonObject();
innerObj.addProperty("a:"+objectList.get(i).getA());
innerObj.addProperty("b:"+objectList.get(i).getB());
sArr.add(innerObj);
}
jObj.addProperty("s", sArr);
The output is:
{
"p":1,
"s":[{"a":1,"b":2},{"a":3,"b":4}]
}
Coderanch
coderanch.com › t › 713115 › java › conversion-array-list-Json-object
conversion of array list to Json object string (Java in General forum at Coderanch)
July 19, 2019 - programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other Pie Elite all forums · this forum made possible by our volunteer staff, including ... ... Hi I have two lists Edge1List and Edge2List which I add to element on them. Edge1List:[o,p] and Edge2List: [p,null]. I convert Edge1List and Edge2List to JsonArray with the name of EdgeJsonArray1 and EdgeJsonArray2 respectively.
Geoffrey
geoffrey.run › computing › java-stream-api-arraylist-to-jsonarray
Java Stream API: ArrayList to JsonArray - Geoffrey's Blog
// set up example ArrayList<Pet> pets = new ArrayList<>(); pets.add(new Pet("Goldie", "Fish")); pets.add(new Pet("Daisy", "Cow")); pets.add(new Pet("Snowball", "Cat")); // the work pets.stream() .map((a) -> { return Json.createObjectBuilder() .add("id", a.getName()) .add("type", a.getGroup()) .build(); }) .collect( Json::createArrayBuilder, JsonArrayBuilder::add, JsonArrayBuilder::add ) .build(); The .map operation of the stream API takes a Function<T,R>. The function converts each item to a JsonObject.
IQCode
iqcode.com › code › javascript › arraylist-to-json-array
arraylist to json array Code Example
September 5, 2021 - ArrayList<String> list = new ArrayList<String>(); list.add("foo"); list.add("baar"); JSONArray jsArray = new...
Top answer 1 of 5
23
You can use the GSON library to accomplish this.
ArrayList<String> mylist = new ArrayList<String> ();
mylist.add("abc");
mylist.add("cfd");
mylist.add("ert");
mylist.add("fg");
mylist.add("ujk");
String json = new Gson().toJson(mylist);
You can refer to the GSON User Guide for more support.
2 of 5
9
JSONArray jsArray = new JSONArray(mylist);
Or
Gson gson = new Gson();
String jsonArray = gson.toJson(mylist);
Get java-json.jar and Gson.jar here
Top answer 1 of 5
3
Simple example :
List<Model> data = new ArrayList<>();
JSONArray jsonArray = jsonObject.getJSONArray("data");
for (int i = 0; i < jsonArray.length(); i++) {
data.add(new Model(/*fill your data*/));
}
2 of 5
1
Move this before the for loop
ArrayList<OrderUser> listOrderUser = new ArrayList<OrderUser>();
Then simply add an item using, listOrderUser.add(<your_model_item>);
and after the for loop, do a notifyDataSetChanged(); on the recyclerView Adapter