How to show dropdown of suggestions in autcompletetextview – Photoshop

I want to show all the suggestions to the user when the textfield is empty, I am getting my suggestions from json response, when user types the word it appears in dropdown but when the textfield is empty it doesn’t show anything i even tried showDropDown() but the Android Monitor says: Attempted to finish an input event but the input event receiver has already been disposed.

Here is my code:

public class MainActivity extends AppCompatActivity {
AutoCompleteTextView acTextView;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    acTextView = (AutoCompleteTextView) findViewById(R.id.autoComplete);
    acTextView.setAdapter(new SuggestionAdapter(this,acTextView.getText().toString()));
    acTextView.setThreshold(0);

    acTextView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            acTextView.showDropDown();
        }
    });
        }
    });
  }
}

i get my suggestion adapter from these classes first
JSON Parser which parse the keywords from URL.
A getter setter class.
Suggestions Adapter which sets the filtered items in adapter.
My JSON response:

 [{"lookupValueId":350,"lookupTypeId":33,"lookupValue":"Java"},{"lookupValueId":351,"lookupTypeId":33,"lookupValue":"C++"},{"lookupValueId":352,"lookupTypeId":33,"lookupValue":"Photoshop"},{"lookupValueId":353,"lookupTypeId":33,"lookupValue":"Java Script"}]

JSON Parser Class:

public class JsonParse {


public List<SuggestGetSet> getParseJsonWCF(String sName)
{
    List<SuggestGetSet> ListData = new ArrayList<SuggestGetSet>();
    try {
        String temp = sName.replace(" ", "%20");
        URL js = new URL("http://SomeUrl" + temp + "%22%7D%7D");
                    URLConnection jc = js.openConnection();
        BufferedReader reader = new BufferedReader(new InputStreamReader(jc.getInputStream()));
        String line = reader.readLine();
        JSONArray jsonResponse = new JSONArray(line);
        System.out.print("DATA: " + line);
        for(int i = 0; i < jsonResponse.length(); i++){
            JSONObject r = jsonResponse.getJSONObject(i);
            ListData.add(new SuggestGetSet(r.getInt("lookupValueId"),r.getString("lookupValue")));
        }
    } catch (Exception e1) {
        e1.printStackTrace();
    }
    return ListData;

   }
}

Getter setter class:

public class SuggestGetSet {
String name;
static Integer id;
public SuggestGetSet(int id, String name){
    this.setId(id);
    this.setName(name);
}
public static Integer getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
  }
}

And finally the Adapter class:

class SuggestionAdapter extends ArrayAdapter<String> {

private List<String> suggestions;

SuggestionAdapter(Activity context,String nameFilter) {
    super(context, android.R.layout.simple_dropdown_item_1line);
    suggestions = new ArrayList<>();
}


@Override
public int getCount() {
    return suggestions.size();
}

@Override
public String getItem(int index) {
    return suggestions.get(index);
}

@NonNull
@Override
public Filter getFilter() {
    return new Filter() {
        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            FilterResults filterResults = new FilterResults();
            JsonParse jp = new JsonParse();
            if (constraint != null) {
                // A class that queries a web API, parses the data and
                // returns an ArrayList<GoEuroGetSet>
                List<SuggestGetSet> new_suggestions = jp.getParseJsonWCF(constraint.toString());
                suggestions.clear();
                for (int i = 0; i < new_suggestions.size(); i++) {
                    suggestions.add(new_suggestions.get(i).getName());
                }

                // Now assign the values and count to the FilterResults
                // object
                filterResults.values = suggestions;
                filterResults.count = suggestions.size();
            }
            return filterResults;
        }

        @Override
        protected void publishResults(CharSequence constraint,
                                      FilterResults results) {
            if (results != null && results.count > 0) {
                notifyDataSetChanged();
            } else {
                notifyDataSetInvalidated();
            }
        }
    };
  }
}

I followed this referrence: http://manishkpr.webheavens.com/android-autocompletetextview-example-json/