How to convert ArrayList to JSON object

Question

public ArrayList<String> convertJsonToJsonObject(){
 ArrayList<String> mylist = new ArrayList<String> ();
 mylist.add("abc");
 mylist.add("cfd");
 mylist.add("ert");
 mylist.add("fg");
 mylist.add("ujk");
 mylist.add("wer");
 mylist.add("dvb");
 mylist.add("ert");
 System.out.println("JSONObject :: "+(JSONObject)JSONSerializer.toJson(mylist));
}

I am having error at .toJson() method, I am not sure what is the mistake I am making.

• nos: 1. What does the error say ? 2. Which Json library are you using ?

Answer 1

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.

• rageandqq: Be sure to include the GSON library in your project!
• newbie: i am trying to convert the array into json object.JSONArray jsArray = new JSONArray(mylist); System.out.println("print the array" + jsArray); for (int i = 0; i < mylist.size(); i++) { jsArray.put(mylist.get(i)); } JSONObject obj = new JSONObject(); System.out.println("print he object" + obj)

Answer 2

JSONArray jsArray = new JSONArray(mylist);

Or

Gson gson = new Gson();
String jsonArray = gson.toJson(mylist);

Get java-json.jar and Gson.jar here

• newbie: i got the output in array["acb ", "adg ", "tyy " ].Now i would like to convert the json array to json object.is there any way i can do it?
• SparkOn: Hi whatever you are getting it is the json object
• SparkOn: Did you understand the concept now may be you were confused because it was not key value pair Read this you will understand it

Answer 3

gson.toJson(object);

Gson Google Group

• newbie: It says,The method toJson(ArrayList<String>) is undefined for the type Object.@Peter Liljenberg
• dikkini: List<String> mylist = new ArrayList<> (); myList.add("hello"); System.out.println(new Gson().toJson(mylist));
• dikkini: Oh, i understand. I give you link to Google Code of this library, you have to download it and add to dependency of your project.

Answer 4

ArrayList<Domain> list = new ArrayList<Domain>();
list.add(new Domain());
list.add(new Domain());
list.add(new Domain());
String json = new Gson().toJson(list);

• Arun Joseph: Can U say how to retrive back the values in list?
• Shaaban Ebrahim: @ArunJoshla List<Domain> videos = gson.fromJson(json, new TypeToken<List<Domain>>(){}.getType()); , json is string value that initialized last line of answer

Answer 5

List<String> bibo = new ArrayList<String>();
bibo.add("obj1");
bibo.add("obj2");
bibo.add("obj3");
String json = new Gson().toJson(bibo);