YARN-11235. Fix CheckStyle.

Author: slfan1989

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/java/org/apache/hadoop/yarn/server/federation/policies/router/AbstractRouterPolicy.java

@@ -161,8 +161,7 @@ public SubClusterId getHomeSubcluster(ApplicationSubmissionContext appContext,
   public SubClusterId getReservationHomeSubcluster(ReservationSubmissionRequest request)
       throws YarnException {
     if (request == null) {
-      throw new FederationPolicyException(
-          "The ReservationSubmissionRequest cannot be null.");
+      throw new FederationPolicyException("The ReservationSubmissionRequest cannot be null.");
     }
 
     if (request.getQueue() == null) {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/java/org/apache/hadoop/yarn/server/federation/policies/router/LocalityRouterPolicy.java

@@ -133,14 +133,14 @@ public SubClusterId getHomeSubcluster(
           targetId = resolver.getSubClusterForNode(rr.getResourceName());
           nodeRequest = rr;
         } catch (YarnException e) {
-          LOG.error("Cannot resolve node.", e);
+          LOG.error("Cannot resolve node.");
         }
         // Handle "rack" requests
         try {
           resolver.getSubClustersForRack(rr.getResourceName());
           rackRequest = rr;
         } catch (YarnException e) {
-          LOG.error("Cannot resolve rack.", e);
+          LOG.error("Cannot resolve rack.");
         }
         // Handle "ANY" requests
         if (ResourceRequest.isAnyLocation(rr.getResourceName())) {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/java/org/apache/hadoop/yarn/server/federation/policies/router/UniformRandomRouterPolicy.java

@@ -63,7 +63,7 @@ public void reinitialize(FederationPolicyInitializationContext policyContext)
   @Override
   protected SubClusterId chooseSubCluster(
       String queue, Map<SubClusterId, SubClusterInfo> preSelectSubClusters) throws YarnException {
-    if(preSelectSubClusters == null || preSelectSubClusters.size() == 0) {
+    if (preSelectSubClusters == null || preSelectSubClusters.isEmpty()) {
       throw new FederationPolicyException("No available sub-cluster to choose from.");
     }
     List<SubClusterId> list = new ArrayList<>(preSelectSubClusters.keySet());

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/java/org/apache/hadoop/yarn/server/federation/policies/router/WeightedRandomRouterPolicy.java

@@ -43,22 +43,21 @@ protected SubClusterId chooseSubCluster(
     // changes dynamically (and this would unfairly spread the load to
     // sub-clusters adjacent to an inactive one), hence we need to count/scan
     // the list and based on weight pick the next sub-cluster.
-    Map<SubClusterIdInfo, Float> weights =
-            getPolicyInfo().getRouterPolicyWeights();
+    Map<SubClusterIdInfo, Float> weights = getPolicyInfo().getRouterPolicyWeights();
 
     ArrayList<Float> weightList = new ArrayList<>();
     ArrayList<SubClusterId> scIdList = new ArrayList<>();
     for (Map.Entry<SubClusterIdInfo, Float> entry : weights.entrySet()) {
-      if (entry.getKey() != null && preSelectSubClusters.containsKey(entry.getKey().toId())) {
+      SubClusterIdInfo key = entry.getKey();
+      if (key != null && preSelectSubClusters.containsKey(key.toId())) {
         weightList.add(entry.getValue());
-        scIdList.add(entry.getKey().toId());
+        scIdList.add(key.toId());
       }
     }
 
     int pickedIndex = FederationPolicyUtils.getWeightedRandom(weightList);
     if (pickedIndex == -1) {
-      throw new FederationPolicyException(
-          "No positive weight found on active subClusters.");
+      throw new FederationPolicyException("No positive weight found on active subclusters");
     }
     return scIdList.get(pickedIndex);
   }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/test/java/org/apache/hadoop/yarn/server/federation/policies/BaseFederationPoliciesTest.java

@@ -19,7 +19,6 @@
 package org.apache.hadoop.yarn.server.federation.policies;
 
 import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
 
 import java.nio.ByteBuffer;
 import java.util.HashMap;
@@ -40,7 +39,12 @@
 import org.apache.hadoop.yarn.server.federation.policies.router.FederationRouterPolicy;
 import org.apache.hadoop.yarn.server.federation.store.FederationStateStore;
 import org.apache.hadoop.yarn.server.federation.store.impl.MemoryFederationStateStore;
-import org.apache.hadoop.yarn.server.federation.store.records.*;
+import org.apache.hadoop.yarn.server.federation.store.records.SubClusterId;
+import org.apache.hadoop.yarn.server.federation.store.records.SubClusterIdInfo;
+import org.apache.hadoop.yarn.server.federation.store.records.SubClusterInfo;
+import org.apache.hadoop.yarn.server.federation.store.records.SubClusterPolicyConfiguration;
+import org.apache.hadoop.yarn.server.federation.store.records.SubClusterState;
+import org.apache.hadoop.yarn.server.federation.store.records.SubClusterRegisterRequest;
 import org.apache.hadoop.yarn.server.federation.utils.FederationPoliciesTestUtil;
 import org.apache.hadoop.yarn.server.federation.utils.FederationStateStoreFacade;
 import org.junit.Test;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/test/java/org/apache/hadoop/yarn/server/federation/policies/router/BaseRouterPoliciesTest.java

@@ -37,7 +37,6 @@
 import org.junit.Assert;
 import org.junit.Test;
 
-import static org.mockito.Mockito.when;
 
 /**
  * Base class for router policies tests, tests for null input cases.