[apache/helix] -- Updated code to be build compatible with JDK-8. (ap…

…ache#2650)

We will release codebase to be build with JDK-8. We will continue to release the Open source Helix on Java 11 and this PR is for backward compatibility.

helix-core/src/main/java/org/apache/helix/controller/rebalancer/DelayedAutoRebalancer.java

@@ -19,6 +19,7 @@
  * under the License.
  */
 
+import com.google.common.collect.ImmutableSet;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
@@ -55,7 +56,7 @@
  */
 public class DelayedAutoRebalancer extends AbstractRebalancer<ResourceControllerDataProvider> {
   private static final Logger LOG = LoggerFactory.getLogger(DelayedAutoRebalancer.class);
-   public static final Set<String> INSTANCE_OPERATION_TO_EXCLUDE_FROM_ASSIGNMENT = Set.of("EVACUATE", "SWAP_IN");
+   public static final Set<String> INSTANCE_OPERATION_TO_EXCLUDE_FROM_ASSIGNMENT = ImmutableSet.of("EVACUATE", "SWAP_IN");
 
   @Override
   public IdealState computeNewIdealState(String resourceName,

helix-core/src/main/java/org/apache/helix/controller/rebalancer/util/DelayedRebalanceUtil.java

@@ -400,7 +400,7 @@ private static Map<String, List<String>> findPartitionsMissingMinActiveReplica(
       Map<String, ResourceAssignment> currentAssignment) {
     return currentAssignment.entrySet()
         .parallelStream()
-        .map(e -> Map.entry(e.getKey(), findPartitionsMissingMinActiveReplica(clusterData, e.getValue())))
+        .map(e -> new HashMap.SimpleEntry<>(e.getKey(), findPartitionsMissingMinActiveReplica(clusterData, e.getValue())))
         .filter(e -> !e.getValue().isEmpty())
         .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
   }

helix-core/src/main/java/org/apache/helix/controller/rebalancer/waged/WagedRebalancer.java

@@ -19,6 +19,7 @@
  * under the License.
  */
 
+import com.google.common.collect.ImmutableList;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
@@ -80,7 +81,7 @@ public class WagedRebalancer implements StatefulRebalancer<ResourceControllerDat
           .getInstance(ClusterConfig.DEFAULT_GLOBAL_REBALANCE_PREFERENCE);
   // These failure types should be propagated to caller of computeNewIdealStates()
   private static final List<HelixRebalanceException.Type> FAILURE_TYPES_TO_PROPAGATE =
-      List.of(HelixRebalanceException.Type.INVALID_REBALANCER_STATUS, HelixRebalanceException.Type.UNKNOWN_FAILURE);
+      ImmutableList.of(HelixRebalanceException.Type.INVALID_REBALANCER_STATUS, HelixRebalanceException.Type.UNKNOWN_FAILURE);
 
   private final HelixManager _manager;
   private final MappingCalculator<ResourceControllerDataProvider> _mappingCalculator;

helix-core/src/main/java/org/apache/helix/controller/rebalancer/waged/constraints/ConstraintBasedAlgorithm.java

@@ -100,7 +100,7 @@ public OptimalAssignment calculate(ClusterModel clusterModel) throws HelixRebala
           getNodeWithHighestPoints(replica, nodes, clusterModel.getContext(), busyInstances,
               optimalAssignment);
       // stop immediately if any replica cannot find best assignable node
-      if (maybeBestNode.isEmpty() || optimalAssignment.hasAnyFailure()) {
+      if (!maybeBestNode.isPresent() || optimalAssignment.hasAnyFailure()) {
         String errorMessage = String.format(
             "Unable to find any available candidate node for partition %s; Fail reasons: %s",
             replica.getPartitionName(), optimalAssignment.getFailures());

helix-core/src/main/java/org/apache/helix/controller/rebalancer/waged/model/ClusterModelProvider.java

@@ -581,7 +581,7 @@ private static Map<String, Set<AssignableReplica>> getAllAssignableReplicas(
           }
         }
       }
-      return Map.entry(resourceName, replicas);
+      return new HashMap.SimpleEntry<>(resourceName, replicas);
     }).collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
   }
 

helix-core/src/test/java/org/apache/helix/controller/rebalancer/waged/TestWagedRebalancer.java

@@ -20,6 +20,7 @@
  */
 
 import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
 import java.io.IOException;
 import java.util.Collections;
 import java.util.HashMap;
@@ -737,7 +738,7 @@ public void testRebalanceOverwrite() throws HelixRebalanceException, IOException
     instances.add(offlineInstance);
     when(clusterData.getAllInstances()).thenReturn(instances);
     when(clusterData.getEnabledInstances()).thenReturn(instances);
-    when(clusterData.getEnabledLiveInstances()).thenReturn(Set.of(instance0, instance1, instance2));
+    when(clusterData.getEnabledLiveInstances()).thenReturn(ImmutableSet.of(instance0, instance1, instance2));
     Map<String, Long> instanceOfflineTimeMap = new HashMap<>();
     instanceOfflineTimeMap.put(offlineInstance, System.currentTimeMillis() + Integer.MAX_VALUE);
     when(clusterData.getInstanceOfflineTimeMap()).thenReturn(instanceOfflineTimeMap);
@@ -862,10 +863,10 @@ private void validateRebalanceResult(Map<String, Resource> resourceMap,
   public void testResourceWeightProvider() throws IOException {
     ResourceControllerDataProvider testCache = setupClusterDataCache();
     WagedResourceWeightsProvider dataProvider = new WagedResourceWeightsProvider(testCache);
-    Map<String, Integer> weights1 = Map.of("item1", 3, "item2", 6, "item3", 0);
+    Map<String, Integer> weights1 = ImmutableMap.of("item1", 3, "item2", 6, "item3", 0);
     Assert.assertEquals(dataProvider.getPartitionWeights("Resource1", "Partition1"), weights1);
     Assert.assertEquals(dataProvider.getPartitionWeights("Resource1", "Partition2"), weights1);
-    Map<String, Integer> weights2 = Map.of("item1", 5, "item2", 10, "item3", 0);
+    Map<String, Integer> weights2 = ImmutableMap.of("item1", 5, "item2", 10, "item3", 0);
     Assert.assertEquals(dataProvider.getPartitionWeights("Resource2", "Partition2"), weights2);
   }
 
@@ -898,7 +899,7 @@ public void testInstanceCapacityProvider() throws IOException, HelixRebalanceExc
         }));
     WagedInstanceCapacity provider = new WagedInstanceCapacity(clusterData);
 
-    Map<String, Integer> weights1 = Map.of("item1", 20, "item2", 40, "item3", 30);
+    Map<String, Integer> weights1 = ImmutableMap.of("item1", 20, "item2", 40, "item3", 30);
     Map<String, Integer> capacity = provider.getInstanceAvailableCapacity("testInstanceId");
     Assert.assertEquals(provider.getInstanceAvailableCapacity("testInstanceId"), weights1);
     Assert.assertEquals(provider.getInstanceAvailableCapacity("testInstanceId1"), weights1);

helix-core/src/test/java/org/apache/helix/controller/stages/TestCurrentStateComputationStage.java

@@ -19,6 +19,8 @@
  * under the License.
  */
 
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.List;
@@ -50,9 +52,9 @@ public void testEmptyCS() {
     CurrentStateComputationStage stage = new CurrentStateComputationStage();
     runStage(event, new ReadClusterDataStage());
     ClusterConfig clsCfg = dataCache.getClusterConfig();
-    clsCfg.setInstanceCapacityKeys(List.of("s1", "s2", "s3"));
+    clsCfg.setInstanceCapacityKeys(ImmutableList.of("s1", "s2", "s3"));
     dataCache.setClusterConfig(clsCfg);
-    dataCache.setInstanceConfigMap(Map.of(
+    dataCache.setInstanceConfigMap(ImmutableMap.of(
         "a", new InstanceConfig("a")
     ));
     runStage(event, stage);