A simple class for caching RetroFit REST clients

ServiceClient.java

public class ServiceClient {
    public interface ServiceClientDelegate {
        Client getClient();
    }

    private static ServiceClient instance;

    private final int CONNECTION_TIMEOUT = 60000;

    private RestAdapter mRestAdapter;
    private Map<String, Object> mClients = new HashMap<String, Object>();

    public static ServiceClient getInstance() {
        if (null == instance) {
            instance = new ServiceClient();
        }
        return instance;
    }

    public void configureRestAdapter(String baseServerPath, Client client) {
        mRestAdapter = new RestAdapter.Builder().setServer(new Server(baseServerPath)).setClient(client).build();
    }

    @SuppressWarnings("unchecked")
    public <T> T getClient(Class<T> clazz) {
        if (mRestAdapter == null) {
            return null;
        }
        T client = null;
        if ((client = (T) mClients.get(clazz.getCanonicalName())) != null) {
            return client;
        }
        client = mRestAdapter.create(clazz);
        mClients.put(clazz.getCanonicalName(), client);
        return client;
    }

}