PaymentMethodsAsync.java

public class PaymentMethodsActivity extends Activity {

  private String mMerchantPublicKey;
  private String mPaymentTypeSupported;
    
    @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_payment_methods);
      
      mMerchantPublicKey = this.getIntent().getStringExtra("merchantPublicKey");
      
      MercadoPago mercadoPago = new MercadoPago.Builder()
              .setContext(this)
              .setPublicKey(mMerchantPublicKey)
              .build();
      getPaymentMethodsAsync(mercadoPago);
  }
  
  private void getPaymentMethodsAsync(MercadoPago mercadoPago) {

    mercadoPago.getPaymentMethods(new Callback <List<PaymentMethod>>() {
        @Override
        public void success(List<PaymentMethod> paymentMethods, Response response) {
          // Ya tenés la lista de medios de pago!
          // Ahora armá tu UI para cada uno de ellos!
        }
  
        @Override
        public void failure(RetrofitError error) {
          // UPS! Algo salió mal.
        }
    });
  }
}