Mockito using spy object running actual code hence giving error - jax-rs

Question

I have this bunch of code. First is a test class method testEndPoint(), I have also included the class to be tested EndPointClass.
When I run this testmethod, it tries to run the actual send http Call method instead of mocking or a dummy call, hence it gives a 500 not found error.
I know somewhere the code needs to be corrected not sure where.
Here's the code
public void testEndPoint(){
OutputObject output = new OutputObject();
EndPointClass epClass = new EndPointClass();
EndPointClass epClassSpy = Mockito.spy(epClass);
List<JacksonJsonProvider> providers = new ArrayList<JacksonJsonProvider>();
providers.add(mockCustomJacksonProvider);
WebClient client = WebClient.create("http://example.org/home",providers);
WebClientWrapper webClientWrapper = new WebClientWrapper(client);
WebClientWrapper spyWebClient = Mockito.spy(webClientWrapper);
Mockito.when(spyWebClient.invoke(Mockito.any(String.class),Mockito.any(Object.class),Mockito.eq(OutputObject.class))).thenReturn(output);
Mockito.when(epClassSpy.webCall(spyWebClient)).thenReturn(output);
OutputObject response = epClassSpy.sendRequest("ABC", "ABCToken");
}
public class EndPointClass{
public OutputObject sendRequest(String input, String authToken){
List<JacksonJsonProvider> providers = new ArrayList<JacksonJsonProvider>();
providers.add(downloadsJacksonProvider);
WebClient client = WebClient.create(olsDownloadUrl+path, providers);
if (null == timeOut) {
timeOut = 60000;
}
HTTPConduit http = (HTTPConduit) WebClient.getConfig(client).getConduit();
HTTPClientPolicy httpClientPolicy = new HTTPClientPolicy();
httpClientPolicy.setConnectionTimeout(0);
httpClientPolicy.setReceiveTimeout(timeOut);
http.setClient(httpClientPolicy);
client.type("application/json");
client.accept("application/json");
client.header("x-auth-Token", authToken);
client.query("input", input);
OutputObject output = null;
WebClientWrapper clientWrapper = new WebClientWrapper(client);
output = webCall(clientWrapper);
return output;
}
public OutputObject webCall(WebClientWrapper clientWrapper) {
return clientWrapper.invoke(HttpMethod.GET, null, OutputObject.class);
}
}

Answer 1

From the official documentation
Important gotcha on spying real objects!
Sometimes it's impossible or impractical to use when(Object) for stubbing spies. Therefore when using spies please consider doReturn|Answer|Throw() family of methods for stubbing. Example:
List list = new LinkedList();
List spy = spy(list);
//Impossible: real method is called so spy.get(0) throws ndexOutOfBoundsException (the list is yet empty)
when(spy.get(0)).thenReturn("foo");
//You have to use doReturn() for stubbing
doReturn("foo").when(spy).get(0);
So just change your Mockito.when(...) to Mockito.doReturn(...) that should do the trick.