Arraylist of strings into one comma separated string

Question

Trying to convert a Arraylist of strings into one big comma separated string.

However when I use the

String joined = TextUtils.join(\", \", partici         


        

Answer 1

I'm trying to reproduce your error and am unable to. Here is my code:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_temp);

    List list = new ArrayList<>();
    list.add("Philip Johnson");
    list.add("Paul Smith");
    list.add("Raja P");
    list.add("Ezhu Malai");

    String s = TextUtils.join(", ", list);

    Log.d(LOGTAG, s);
}

My output is Philip Johnson, Paul Smith, Raja P, Ezhu Malai as expected.

Are you importing the correct TextUtils class?

android.text.TextUtils;

Given the new information, here is my approach:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_temp);

    callApi(type, new OnResponseListener>() {
        @Override public void onResponse(List list) {
            getSupportActionBar().setTitle(TextUtils.join(", ", list));
        }
    });
}

I don't know what networking library you're using, but you may have to define OnResponseListener as an interface. It's very easy:

public interface OnResponseListener {
    public void onResponse(T response);
}

You will then need to modify your callApi function to take an instance of OnResponseListener> and call it's onResponse method after completing the call.

I would recommend looking into the Volley library, and reading the Android documentation about simple network calls.