X-Git-Url: http://juplo.de/gitweb/?a=blobdiff_plain;f=src%2Fmain%2Fjava%2Fde%2Fjuplo%2Fkafka%2FAdderBusinessLogic.java;h=cbd500dcdab4de973960aa6ca8bf52fa3be21f46;hb=b9a482c8228e0b9197d7cb0c3f6b8849e5cd66da;hp=ecd9590de696b14501145682be4dbd58a0b6c955;hpb=d576eea9bc9208d9e5003bd8c8c132bed96b5c40;p=demos%2Fkafka%2Ftraining

diff --git a/src/main/java/de/juplo/kafka/AdderBusinessLogic.java b/src/main/java/de/juplo/kafka/AdderBusinessLogic.java
index ecd9590..cbd500d 100644
--- a/src/main/java/de/juplo/kafka/AdderBusinessLogic.java
+++ b/src/main/java/de/juplo/kafka/AdderBusinessLogic.java
@@ -29,13 +29,14 @@ public class AdderBusinessLogic
 
   public synchronized void addToSum(String user, Integer value)
   {
-    if (!state.containsKey(user))
-      throw new IllegalStateException("No sumation for " + user + " in progress");
     if (value == null || value < 1)
       throw new IllegalArgumentException("Not a positive number: " + value);
 
-    long result = state.get(user) + value;
-    state.put(user, result);
+    long sum =
+        Optional
+            .ofNullable(state.get(user))
+            .orElse(0l);
+    state.put(user, sum + value);
   }
 
   public synchronized Long calculate(String user)