X-Git-Url: http://juplo.de/gitweb/?a=blobdiff_plain;f=src%2Fmain%2Fjava%2Fde%2Fjuplo%2Fkafka%2FAdderBusinessLogic.java;h=503fa88684acce65af5c4d7e3ef478a4bb5ce163;hb=f83599b6aaefff62c286e2143bb2e8a81751e6fd;hp=2e3d126394cc66137a1493409b8f57029e7cf1df;hpb=0aa4a1863bf9ee5d345c652f47f350f82d73e4aa;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 2e3d126..503fa88 100644
--- a/src/main/java/de/juplo/kafka/AdderBusinessLogic.java
+++ b/src/main/java/de/juplo/kafka/AdderBusinessLogic.java
@@ -1,13 +1,56 @@
 package de.juplo.kafka;
 
 
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+
+
 public class AdderBusinessLogic
 {
+  private final Map<String, Long> state;
+
+
   public AdderBusinessLogic()
   {
+    this(new HashMap<>());
+  }
+
+  public AdderBusinessLogic(Map<String, Long> state)
+  {
+    this.state = state;
   }
 
+
   public synchronized void startSum(String user)
   {
+    if (state.containsKey(user))
+      throw new IllegalStateException("Sumation for " + user + " already in progress, state: " + state.get(user));
+
+    state.put(user, 0l);
+  }
+
+  public synchronized Optional<Long> getSum(String user)
+  {
+    return Optional.ofNullable(state.get(user));
+  }
+
+  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);
+  }
+
+  public synchronized Long endSum(String user)
+  {
+    if (!state.containsKey(user))
+      throw new IllegalStateException("No sumation for " + user + " in progress");
+
+    return state.get(user);
   }
 }