Question

I am in the process of rewriting a bottle neck in the code of the project I am on, and in doing so I am creating a top level item that contains a self populating Ehcache. I am attempting to write a test to make sure that the basic call chain is established, but when the test executes it hands when retrieving the item from the cache.

Here are the Setup and the test, for reference mocking is being done with Mockito:

@Before
public void SetUp()
{
    testCache = new Cache(getTestCacheConfiguration());
    recordingFactory = new EntryCreationRecordingCache();
    service = new Service<Request, Response>(testCache, recordingFactory); 
}

@Test
public void retrievesResultsFromSuppliedCache()
{
    ResultType resultType = mock(ResultType.class);
    Response expectedResponse = mock(Response.class);
    addToExpectedResults(resultType, expectedResponse);
    Request request = mock(Request.class);
    when(request.getResultType()).thenReturn(resultType);

    assertThat(service.getResponse(request), sameInstance(expectedResponse));
    assertTrue(recordingFactory.requestList.contains(request));
}

private void addToExpectedResults(ResultType resultType,
        Response response) {
    recordingFactory.responseMap.put(resultType, response);

}

private CacheConfiguration getTestCacheConfiguration() {
    CacheConfiguration cacheConfiguration = new CacheConfiguration("TEST_CACHE", 10);
    cacheConfiguration.setLoggingEnabled(false);
    return cacheConfiguration;
}

private class EntryCreationRecordingCache extends ResponseFactory{

    public final Map<ResultType, Response> responseMap = new ConcurrentHashMap<ResultType, Response>();
    public final List<Request> requestList = new ArrayList<Request>();

    @Override
    protected Map<ResultType, Response> generateResponse(Request request) {
        requestList.add(request);
        return responseMap;
    }
}

Here is the ServiceClass

public class Service<K extends Request, V extends Response> {

    private Ehcache cache;

    public Service(Ehcache cache, ResponseFactory factory) {
        this.cache = new SelfPopulatingCache(cache, factory);
    }

    @SuppressWarnings("unchecked")
    public V getResponse(K request)
    {
        ResultType resultType = request.getResultType();
        Element cacheEntry = cache.get(request);
        V response = null;
        if(cacheEntry != null){
            Map<ResultType, Response> resultTypeMap = (Map<ResultType, Response>) cacheEntry.getValue();
            try{
                response = (V) resultTypeMap.get(resultType);
            }catch(NullPointerException e){
                throw new RuntimeException("Result type not found for Result Type: " + resultType);
            }catch(ClassCastException e){
                throw new RuntimeException("Incorrect Response Type for Result Type: " + resultType);
            }
        }
        return response;
    }
}

And here is the ResponseFactory:

public abstract class ResponseFactory implements CacheEntryFactory{

    @Override
    public final Object createEntry(Object request) throws Exception {
        return generateResponse((Request)request);
    }

    protected abstract Map<ResultType,Response> generateResponse(Request request);
}

Answer 1

After wrestling with it for a while, I discovered that the cache wasn’t being initialized. Creating a CacheManager and adding the cache to it resolved the problem.