Improved implementation, fixed build

Author: caarlos0

hystrix-core/src/main/java/com/netflix/hystrix/HystrixRequestCache.java

@@ -23,6 +23,7 @@
 import rx.Observable;
 
 import com.netflix.hystrix.strategy.concurrency.HystrixConcurrencyStrategy;
+import com.netflix.hystrix.strategy.concurrency.HystrixRequestContext;
 import com.netflix.hystrix.strategy.concurrency.HystrixRequestVariableDefault;
 import com.netflix.hystrix.strategy.concurrency.HystrixRequestVariableHolder;
 import com.netflix.hystrix.strategy.concurrency.HystrixRequestVariableLifecycle;
@@ -100,6 +101,9 @@ private static HystrixRequestCache getInstance(RequestCacheKey rcKey, HystrixCon
     /* package */<T> Observable<T> get(String cacheKey) {
         ValueCacheKey key = getRequestCacheKey(cacheKey);
         if (key != null) {
+            if (!HystrixRequestContext.isCurrentThreadInitialized()) {
+                throw new IllegalStateException("Failed to get HystrixRequestVariable. Maybe you need to initialize the HystrixRequestContext?");
+            }
             /* look for the stored value */
             return (Observable<T>) requestVariableForCache.get(concurrencyStrategy).get(key);
         }

hystrix-core/src/main/java/com/netflix/hystrix/strategy/concurrency/HystrixRequestVariableHolder.java

@@ -65,11 +65,7 @@ public T get(HystrixConcurrencyStrategy concurrencyStrategy) {
             }
         }
 
-        T result = (T) requestVariableInstance.get(key).get();
-        if (result == null) {
-            throw new IllegalStateException("Failed to get HystrixRequestVariable. Maybe you need to initialize the HystrixRequestContext?");
-        }
-        return result;
+        return (T) requestVariableInstance.get(key).get();
     }
 
     private static class RVCacheKey {