Unable to Mock Glassfish Jersey Client response object

Question

I am having problems with creating a mock Response object to use with my unit tests. I am using org.glassfish.jersey.core.jersey-client version 2.3.1 to implement my RESTful client and mockito version 1.9.5 to help me with mock objects. Here is my test's code:

@Test
public void testGetAll() throws IOException {
    // Given
    String expectedResource = "expectedResource"

    final Response expectedRes =  Response.ok(expectedResource, MediaType.APPLICATION_JSON).build();
    String receivedResource;

    BDDMockito.given(this.client.getSimpleClient().getAllWithResponse()).willReturn(expectedRes);

    // When
    receivedResource = this.client.getAll();

    // Then
    Assert.assertNotNull("Request constructed correctly and response received.", receivedResource);
    Assert.assertEquals("Resource is equal to expected.", expectedResource, receivedResource);
}

The problem occurs when this.client.getAll(); is executed. Here is that method's code:

public String getAll() throws GenericAragornException, ProcessingException{
    Response response = this.simpleClient.getAllWithResponse();

    if (response.getStatus() != 200) {
        processErrorResponse(response);
    }

    String entity = response.readEntity(String.class);

    // No errors so return entity converted to resourceType.
    return entity;
}

Note that I am mocking the this.simpleClient.getAllWithResponse() method with the manually created Response. When it reaches the response.readEntity(resourceListType); instruction, Jersey throws the following exception: java.lang.IllegalStateException - Method not supported on an outbound message.. After lots of research and debugging, it turns that, for some reason, when I create a Response using the response builder such as Response.ok(expectedResource, MediaType.APPLICATION_JSON).build(); it creates it as an OutboundResponse instead of as an InboundResponse. The latter are the only ones permitted to use the Response.readEntity() method. If it is an OutboundResponse, the exception is thrown.

However, I could not find any way of converting the manually created response to an InboundResponse. So my tests are doomed :(. Do you guys/gals have any idea of what I can do here? I don't want to mock the Response object with Mockito because I think it could be a code smell since it violates the Law of Demeter. Sincerely I am out of ideas here. Things like this should be simple and straightforward.

Answer 1

I had this error because when you use the ResponseBuilder, it returns an OutboundJaxrsResponse message that can not be processed with readEntity().

I noticed that I had this error only when I was calling the Jax-RS component directly. For exemple, if I have DefaultController annotated with @Path("/default") and if I tried to directly call its method, I could not use readEntity() and had the same error as you.

defaultController.get();

Now, when I was using the grizzly2 test provider and using a client to target the Rest Url (in the previous case, it is /default), the message I received in response was a ScopedJaxrsResponse. And then I could use the readEntity() method.

target("/default").request.get();

In your case, you mocked the simpleClient in order to reply with a response built with ResponseBuilder that is not processed by jersey. It's comparable to calling directly my DefaultController method.

Without mocking the readEntity() method, I suggest you to find a way to get your response processed by Jersey and turned into a ScopedJaxrsResponse.

Hope that helps.