Is there a way to display the drop down spinner list on page loads in android?

I want to display the list of my array in the spinner when the page first loads and also when the user touches on the spinner.

I am doing this :

String[] simpleArray = {"java","android","Data Structures","HTML","CSS"};

        ArrayAdapter<String> usageListAdapter = new ArrayAdapter<String>(this, R.layout.spinner_small_text, simpleArray);
        usageListAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        btn_list_type.setAdapter(usageListAdapter);
        btn_list_type.setBackgroundColor(0x00000000);

        btn_list_type.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> arg0, View arg1, int pos, long id) {
                listTypePickerSelected(pos);
            }
            @Override
            public void onNothingSelected(AdapterView<?> arg0) {

            }
        });