OSGi bundle unit testing

gistfile1.java

package org.example.tests;

import junit.framework.TestCase;

import org.example.exchange.api.Exchange;
import org.example.exchange.api.ExchangeListener;
import org.example.model.orders.Order;
import org.example.model.orders.OrderHelper;
import org.example.model.orders.Side;
import org.mockito.Mockito;
import org.osgi.framework.BundleContext;
import org.osgi.framework.FrameworkUtil;
import org.osgi.framework.ServiceReference;
import org.osgi.framework.ServiceRegistration;

import static org.mockito.Mockito.*;

public class ExampleTest extends TestCase {

    private final BundleContext context = FrameworkUtil.getBundle(this.getClass()).getBundleContext();

    public void testExample() throws Exception {
      ServiceReference[] refs = context.getAllServiceReferences("org.example.exchange.api.Exchange", null);
    	assertEquals(1, refs.length);
    	
    	ExchangeListener mockListener = mock(ExchangeListener.class);
    	ServiceRegistration mockReg = context.registerService(ExchangeListener.class.getName(), mockListener, null);
    	
    	Exchange exchange = (Exchange) context.getService(refs[0]);
    	
    	Order order = OrderHelper.createOrder();
    	order.setSide(Side.OFFER);
    	order.setSymbol("MSFT");
    	exchange.submitOrder(order);
    	
    	context.ungetService(refs[0]);
    	mockReg.unregister();
    	
    	verify(mockListener).orderSubmitted(eq(exchange), anyString(), eq(order));
    }
}