Change values from one spinner to another in Android

I have 2 spinners in my activity as category and sub-category.
When i choose some value from category spinner
I want to display its related values/data in sub-category spinner.
How can i perform this?

   public class SellActivity extends Activity {
 private Spinner spinner1, spinner2;
 private String selectedOption;
 List<String> addItemList = new ArrayList<String>();
 String[] elCat = new String[] {"Mobile", "Television", "Computers","Home Appliances","Games","Others"};
 String[] veCat = new String[] {"Cars", "Buses", "Motorcycles","Others"};
 String[] reCat = new String[] {"Apartment", "Plot", "Office","Paying Guest","Others"};
 String[] hCat = new String[] {"Books", "Furniture", "Musical Instrument","Watches","Others"};
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_sell);
    spinner1 = (Spinner) findViewById(R.id.categorySellSpinner);
    spinner2 = (Spinner) findViewById(R.id.subCategorySpinner);
    selectedOption=String.valueOf(spinner1.getSelectedItem());
    System.out.println(selectedOption);
    spinner1.setOnItemSelectedListener(new OnItemSelectedListener() {

        @Override
        public void onItemSelected(AdapterView<?> arg0, View arg1,
                int arg2, long arg3) {
            // TODO Auto-generated method stub
            if(selectedOption.equals("Electronics"))
            {
                Collections.addAll(addItemList, elCat);
                ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(SellActivity.this,android.R.layout.simple_spinner_item, addItemList);
                dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
                dataAdapter.notifyDataSetChanged();
                spinner2.setAdapter(dataAdapter);
            }
            else if(selectedOption.equals("Home - Lifestyle"))
            {
                Collections.addAll(addItemList, hCat);
                ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(SellActivity.this,android.R.layout.simple_spinner_item, addItemList);
                dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
                dataAdapter.notifyDataSetChanged();
                spinner2.setAdapter(dataAdapter);
            }
            else if(selectedOption.equals("Vehicles"))
            {
                Collections.addAll(addItemList, veCat);
                ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(SellActivity.this,android.R.layout.simple_spinner_item, addItemList);
                dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
                dataAdapter.notifyDataSetChanged();
                spinner2.setAdapter(dataAdapter);
            }
            else if(selectedOption.equals("Real Estate"))
            {
                Collections.addAll(addItemList, reCat);
                ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(SellActivity.this,android.R.layout.simple_spinner_item, addItemList);
                dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
                dataAdapter.notifyDataSetChanged();
                spinner2.setAdapter(dataAdapter);
            }
        }
        @Override
        public void onNothingSelected(AdapterView<?> arg0) {
        // TODO Auto-generated method stub

        }
    });

}

}

Here is the whole code.
Data is not changing….plus old data adds onto it

Answer

Just do like this in every if condition :-

Collections.addAll(addItemList, elCat);
ArrayAdapter<String> dataAdapter = new ArrayAdapter<String(this,android.R.layout.simple_spinner_item, addItemList);
dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
dataAdapter.notifyDataSetChanged();
spinner2.setAdapter(dataAdapter);
Source:  http://stackoverflow.com/questions/17922979/change-spinner-data-android