Fix grizzly-jersey cache pb (#5224)

* Update WorldResource.java

* set the correct upper limit

frameworks/Java/grizzly/src-jersey/main/java/hello/WorldResource.java

@@ -4,6 +4,7 @@ import hello.domain.World;
 
 import java.util.Arrays;
 import java.util.Comparator;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.Callable;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
@@ -56,9 +57,11 @@ public class WorldResource {
 			Session session = emf.createEntityManager().unwrap(Session.class);
 			session.setDefaultReadOnly(true);
 			try {
-				for (int i = 0; i < queries; i++) {
-					worlds[i] = (World) session.byId(World.class).load(randomWorld());
-				}
+		        //Pick unique random numbers 
+		        final AtomicInteger i = new AtomicInteger(0);
+		        ThreadLocalRandom.current().ints(1, 10001).distinct().limit(queries).forEach(
+		            (randomValue)->worlds[i.getAndAdd(1)] = (World) session.byId(World.class).load(randomValue)
+		        );
 				return worlds;
 			} finally {
 				session.close();
@@ -85,13 +88,16 @@ public class WorldResource {
 				// in the configuration file
 
 				// 1. Read and update the entities from the DB
-				for (int i = 0; i < queries; i++) {
-					final World world = (World) session.byId(World.class).load(randomWorld());
-					world.setRandomNumber(randomWorld());
-					worlds[i] = world;
-				}
-
-				// 2. Sort the array to prevent transaction deadlock in the DB
+		        final AtomicInteger ii = new AtomicInteger(0);
+		        ThreadLocalRandom.current().ints(1, 10001).distinct().limit(queries).forEach(
+		            (randomValue)->{
+		            		final World world = (World) session.byId(World.class).load(randomValue);
+		            		world.setRandomNumber(randomWorld());
+		            		worlds[ii.getAndAdd(1)]=world;
+		            	}
+		        );
+
+		        // 2. Sort the array to prevent transaction deadlock in the DB
 				Arrays.sort(worlds, Comparator.comparingInt(World::getId));
 
 				// 3. Actually save the entities