What is the best way to retrieve JSON data from database for Android AutoCompleteTextView?

Question

I want to develop a dynamic AutoCompleteTextView for Android that populate with JSON data retrieved from MySQL database. Basically it is not a hard task but where I am facing problem? I am inspired by the jQuery Autocomplete option where dynamically fetch data after input letters. But android AutoCompleteTextView is pre-populated with all JSON data.
I am trying to query from millions of data which is really hard to store. Is there any way to search database for the input dynamically?

Eg:

Such as if user input "a" then it will retrieve the best result for "a" . Then if user type "ab" it will be refreshed and populated with new results from database.

Thanks

Answer 1

I'll give you just a general overview only for your task Which looks like this,

public List<String> suggest; //List of suggestions

 autoComplete.addTextChangedListener(new TextWatcher(){

        public void afterTextChanged(Editable editable) {
            // TODO Auto-generated method stub

        }

        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            // TODO Auto-generated method stub

        }

        public void onTextChanged(CharSequence s, int start, int before, int count) {
            String newText = s.toString();
            new getJson().execute(newText);
        }

    });

getJson AsyncTask -> For retrieving new values from server

 class getJson extends AsyncTask<String,String,String>{

    @Override
    protected String doInBackground(String... key) {
        String newText = key[0];
        newText = newText.trim();
        newText = newText.replace(" ", "+");
        try{
            //Codes to retrieve the data for suggestions
            suggest = new ArrayList<String>();
            JSONArray jArray = new JSONArray(data);
            for(loop the array){
            String SuggestKey = //retrieve values by iterating;
            suggest.add(SuggestKey);
            }

        }catch(Exception e){
            Log.w("Error", e.getMessage());
        }

       //Populate suggestions

        runOnUiThread(new Runnable(){
            public void run(){
                 aAdapter = new ArrayAdapter<String>(getApplicationContext(),R.layout.item,suggest);
                 autoComplete.setAdapter(aAdapter);
                 aAdapter.notifyDataSetChanged();
            }
        });

        return null;
    }

See here for the detail info.