added implementation of CompetitorResultsImpl.hasConflicts

Change-Id: I7b1fa2e0f64f8b2cf3719a3533a63d667c1146b3

java/com.sap.sailing.domain.shared.android/src/com/sap/sailing/domain/abstractlog/race/CompetitorResults.java

@@ -8,5 +8,12 @@ package com.sap.sailing.domain.abstractlog.race;
 public interface CompetitorResults extends Iterable<CompetitorResult> {
     boolean add(CompetitorResult result);
 
+    /**
+     * @return {@code true} if there are more than one {@link CompetitorResult} contained with equal
+     * {@link CompetitorResult#getOneBasedRank() rank}. A client can take this as an indicator that
+     * there may be an inconsistency, caused, e.g., by merging results entered on different devices
+     * concurrently. The client shall use the {@link #iterator()} method to enumerate the
+     * {@link CompetitorResult} objects, finding the conflicting elements.
+     */
     boolean hasConflicts();
 }

java/com.sap.sailing.domain.shared.android/src/com/sap/sailing/domain/abstractlog/race/impl/CompetitorResultsImpl.java

@@ -1,6 +1,8 @@
 package com.sap.sailing.domain.abstractlog.race.impl;
 
 import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Set;
 
 import com.sap.sailing.domain.abstractlog.race.CompetitorResult;
 import com.sap.sailing.domain.abstractlog.race.CompetitorResults;
@@ -10,6 +12,15 @@ public class CompetitorResultsImpl extends ArrayList<CompetitorResult> implement
 
     @Override
     public boolean hasConflicts() {
-        return true; // FIXME just for testing
+        final Set<Integer> oneBasedRanks = new HashSet<>();
+        for (final CompetitorResult r : this) {
+            final int oneBasedRank = r.getOneBasedRank();
+            if (oneBasedRank != 0) {
+                if (!oneBasedRanks.add(oneBasedRank)) {
+                    return true;
+                }
+            }
+        }
+        return false;
     }
 }