YARN-11371. Fix CheckStyle.

Author: slfan1989

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/main/java/org/apache/hadoop/yarn/server/router/RouterServerUtil.java

@@ -18,8 +18,6 @@
 
 package org.apache.hadoop.yarn.server.router;
 
-import org.apache.commons.collections.CollectionUtils;
-import org.apache.commons.collections.MapUtils;
 import org.apache.commons.lang3.math.NumberUtils;
 import org.apache.hadoop.classification.InterfaceAudience.Private;
 import org.apache.hadoop.classification.InterfaceAudience.Public;
@@ -29,9 +27,6 @@
 import org.apache.hadoop.util.StringUtils;
 import org.apache.hadoop.yarn.exceptions.YarnException;
 import org.apache.hadoop.yarn.exceptions.YarnRuntimeException;
-import org.apache.hadoop.yarn.server.federation.policies.FederationPolicyUtils;
-import org.apache.hadoop.yarn.server.federation.store.records.SubClusterId;
-import org.apache.hadoop.yarn.server.federation.store.records.SubClusterInfo;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -40,8 +35,6 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
-import java.util.Map;
-import java.util.Random;
 import java.io.IOException;
 
 /**

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-router/src/main/java/org/apache/hadoop/yarn/server/router/webapp/FederationInterceptorREST.java

@@ -481,8 +481,9 @@ public Response submitApplication(ApplicationSubmissionContextInfo newApp,
    * @param blackList Blacklist avoid repeated calls to unavailable subCluster.
    * @param hsr HttpServletRequest.
    * @param retryCount number of retries.
-   * @return Get response, If the response is empty or status not equal SC_ACCEPTED, the request fails,
-   * if the response is not empty and status equal SC_OK, the request is successful.
+   * @return Get response, If the response is empty or status not equal SC_ACCEPTED,
+   * the request fails, if the response is not empty and status equal SC_OK,
+   * the request is successful.
    * @throws YarnException yarn exception.
    * @throws IOException io error.
    */