Apache Camel Beans Unit Testing

Question

I am using Apache Camel with Spring boot in my application. Currently I am working on a Unit test.

Java Code

• DataRoute class

  from("direct:getData")
  .routeId("getData")
  .bean(DataService.class, "processData")
  .marshal().json(JsonLibrary.Jackson)
  .end();
  

• DataService class

  public Data processData() {
      return new Data("Hello World");
  }
  

• Data Class with getters, setters and Jackson toString method

  private String value;
  

Unit test

• BaseCamelContextUnitText

  public abstract class BaseCamelContextUnitTest extends CamelTestSupport
  {
       @Autowired
       private DataService dataService;
  
       @Produce
       private ProducerTemplate producerTemplate;
  
       public CamelContext getCamelContext() {
           return camelContext;
       } 
  
       @Override
       protected Context createJndiContext() throws Exception {
           JndiContext context = new JndiContext();
           context.bind("dataService", dataService);
           return context;
       }
  
       @Test
       public void shouldProcessData() throws Exception {
            RouteDefinition routeDef = getCamelContext().getRouteDefinition("getData");
            routeDef.adviceWith((ModelCamelContext) getCamelContext(), new RouteBuilder() {
  
               @Override
               public void configure() throws Exception {
                    from("direct:getData")
                      .pipeline("bean:dataService?method=processData");
               }
       });
  
       getCamelContext().start();
  
       String responseData = "{"
          + "\"value\":\"Unit test success\""
          + "}";
  
       Object response = producerTemplate.sendBody("direct:getData",   ExchangePattern.InOut, null);
  
       ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
  ((InputStreamCache) response).writeTo(byteArrayOutputStream);
  
       assertThat(new String(byteArrayOutputStream.toByteArray()), is(responseData));
       }
    }
  

How do I mock

   .bean(DataService.class, "processData")

in the unit test to return a mock Data Object with its default String variable as say "Unit test success" and then test to see if the route would give back the mocked Object instead of the Object with "Hello World" String variable?

Answer 1

This may seem's a late response, but I faced the same thing as described in your case, and I come across a simple way to "mock" the bean step, by using the DefaultRegistry to register the mocked bean into Camel registry, for example :

@Test
 public void shouldProcessData() throws Exception {
   ...
   ...
   DataService dataService = new DataService(...);
   stubBean("dataService", dataService); // put this before calling context.start();

   context.start();
   ...
   ...
}


/**
 * This method inject a stub bean into the registry
 * @param beanName the name of the bean being injected
 * @param instance the stub instance
 */
void stubBean(String beanName, Object instance) {
    DefaultRegistry registry = context.getRegistry(DefaultRegistry.class);
    registry.bind(beanName, instance);
}

Answer 2

You can autowired the DataService in your DataRoute like

@Component
public class DataRoute extends RouteBuilder {

    @Autowired
    private DataService dataService;

    @Override
    public void configure() throws Exception {
        from("direct:getData")
        .routeId("getData")
        .bean(dataService, "processData")
        .marshal().json(JsonLibrary.Jackson)
        .end();
    }

}

So you can mock the DataService as usual.

An alternative is using beanRef("beanName", "methodName") in the Route.