Android Arraylist to JSONObject

Question

Im trying to take the values from the ArrayList and put in to an JSONObject. I have written the below code but it does only put the last value from arraylist to jsonobject

I am trying to achieve this out put.

{"lstContacts":"array_value"},{"lstContacts":"array_value"},{"lstContacts":"array_value"}

This is my code

ArrayList<String> tokens;
JSONObject contactsObj;
..
...
test.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 try {
 for (int i = 0; i < tokens.size(); i++) {
 contactsObj.put("ContactToken", tokens.get(i));
 }
 } catch (JSONException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }
 String jsonStr = contactsObj.toString();
 Log.e("CONTACTS", jsonStr); // adds only last array to json object
 }
 });

• BackSlash: contactsObj needs to be a JSONArray
• Cruncher: The output that you posted is not a valid JSONObject.
• Cruncher: as you can see all the answers provided give you something slightly different. This is a direct result of the fact that we can't tell what you want from the question. You need to figure out exactly what kind of object you're looking for. And by the time you do that, you'll have probably solved the problem on your own anyway
• JakeWilson801: git clone github.com/google/gson.git

Answer 1

Try this:

JSONObject contactsObj = new JSONObject();
JSONArray contactsArray = new JSONArray();
try {
 for (int i = 0; i < tokens.size(); i++) {
 JSONObject contact = new JSONObject();
 contact.put("ContactToken", tokens.get(i));
 contactsArray.put(i, contact);
 }
 contactsObj.put("contacts", contactsArray);
} catch (JSONException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
}
String jsonStr = contactsObj.toString();
Log.e("CONTACTS", jsonStr); // adds only last array to json object

The result jsonStr will look like this:

{ 
 "contacts":[ 
 { 
 "ContactToken":"someToken"
 },
 { 
 "ContactToken":"someToken"
 },
 { 
 "ContactToken":"someToken"
 },
 { 
 "ContactToken":"someToken"
 }
 ]
}

• Cruncher: You should post what the resulting object would look like.

Answer 2

You are overriding the object because u are using an JsonObject for an ArrayList, the solution is to use an JsonArray contactObj in your case

JSONArray contactsObj;
 for (int i = 0; i < tokens.size(); i++) {
 contactsObj.put(i, tokens.get(i));
 }

Answer 3

JSONObject contactsObj = new JSONObject();
for (int i = 0; i < tokens.size(); i++) {
 contactsObj.put("lstContacts" + String.valueOf(i), tokens.get(i));
}
// done...

• Xjasz: A JSONArray is better but he wants a JSONObject

Answer 4

contactsObj.put("ContactTokens", new JSONArray(tokens));

Is probably closest to what you're looking for. You don't even need to loop for this.

This will give you the object

{
 "ContactTokens":["token1","token2","token3"...]
}