The below is the sample code I'm trying to get the selected value from spinner on setOnClickListener method for the Button validateUser.
    public class MainActivity extends Activity implements  AdapterView.OnItemSelectedListener {
      private Button validateUser;
      private Spinner userTypeSpinner;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        userTypeSpinner=(Spinner)findViewById(R.id.userTypeSpinner);
        validateUser= (Button) findViewById(R.id.userValidate);
        validateUser.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(getApplicationContext(), "Button is Selected", Toast.LENGTH_SHORT);
            }
        });
        ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
                R.array.userTypeArray, android.R.layout.simple_spinner_item);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        userTypeSpinner.setAdapter(adapter);
        userTypeSpinner.setOnItemSelectedListener(this);
    }
    @Override
    public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
        String item = adapterView.getItemAtPosition(i).toString();
        Toast.makeText(adapterView.getContext(), "Selected: " + item, Toast.LENGTH_SHORT).show();
    }
    @Override
    public void onNothingSelected(AdapterView<?> adapterView) {
    }
}
				
                        
Toast needs to be shown. use
.show()at the end.Toast.makeText(getApplicationContext(), "Button is Selected", Toast.LENGTH_SHORT).show();