public class MyProjActivity extends Activity {
    
    TextView tv;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
            setContentView(R.layout.main);

            Spinner spinner = (Spinner) findViewById(R.id.spinner1);
            ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
                    this, R.array.planets_array, android.R.layout.simple_spinner_item);
            adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
            spinner.setAdapter(adapter);
            tv = (TextView) findViewById(R.id.textView1);
            spinner.setOnItemSelectedListener(new ML());
    }
}

public class ML extends MyProjActivity implements OnItemSelectedListener {

    @Override
    public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
            long arg3) {
        // TODO Auto-generated method stub
        Toast.makeText(arg0.getContext(), "The planet is " +
                  arg0.getItemAtPosition(arg2).toString(), Toast.LENGTH_LONG).show();
        tv.setText(arg0.getItemAtPosition(arg2).toString());

    }

    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
        // TODO Auto-generated method stub

    }
}