Fix QA bot issues

- Checkstyle warnings
- License headers
- Javadoc tags
- Shading issues

hbase-client/src/main/java/org/apache/hadoop/hbase/client/MasterRegistry.java

@@ -1,3 +1,20 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package org.apache.hadoop.hbase.client;
 
 import static org.apache.hadoop.hbase.HConstants.DEFAULT_HBASE_RPC_TIMEOUT;
@@ -49,12 +66,12 @@
 
 /**
  * Master based registry implementation. Makes RPCs to the configured master addresses from config
- * {@value HConstants#MASTER_ADDRS_KEY}.
+ * {@value org.apache.hadoop.hbase.HConstants#MASTER_ADDRS_KEY}.
  *
  * It has the ability to burst the same RPC to multiple masters as a batch and returns whatever
  * comes back first (a.k.a hedged RPCs). Number of target masters in a single batch is controlled
- * via {@value HConstants#MASTER_REGISTRY_NUM_HEDGED_REQS_KEY}. If it is set to 1 (default), it is
- * equivalent to picking a random master from the configured list.
+ * via {@value org.apache.hadoop.hbase.HConstants#MASTER_REGISTRY_NUM_HEDGED_REQS_KEY}. If it is
+ * set to 1 (default), it is equivalent to picking a random master from the configured list.
  *
  * TODO: Handle changes to the configuration dynamically without having to restart the client.
  */

hbase-client/src/main/java/org/apache/hadoop/hbase/exceptions/MasterRegistryFetchException.java

@@ -1,3 +1,20 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package org.apache.hadoop.hbase.exceptions;
 
 import java.util.List;

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestFromClientSide.java

@@ -5130,7 +5130,7 @@ public void testCheckAndDeleteWithCompareOp() throws IOException {
   * Test ScanMetrics
   */
   @Test
-  @SuppressWarnings ("unused")
+  @SuppressWarnings({"unused", "checkstyle:EmptyBlock"})
   public void testScanMetrics() throws Exception {
     final TableName tableName = name.getTableName();
 
@@ -5169,7 +5169,8 @@ public void testScanMetrics() throws Exception {
       scan2.setScanMetricsEnabled(true);
       scan2.setCaching(numRecords + 1);
       try (ResultScanner scanner = ht.getScanner(scan2)) {
-        for (Result result : scanner.next(numRecords - 1)) {}
+        for (Result result : scanner.next(numRecords - 1)) {
+        }
         scanner.close();
         // closing the scanner will set the metrics.
         assertNotNull(scanner.getScanMetrics());
@@ -5182,8 +5183,8 @@ public void testScanMetrics() throws Exception {
       try (ResultScanner scanner = ht.getScanner(scan2)) {
         // per HBASE-5717, this should still collect even if you don't run all the way to
         // the end of the scanner. So this is asking for 2 of the 3 rows we inserted.
-        for (Result result : scanner.next(numRecords - 1)) {}
-
+        for (Result result : scanner.next(numRecords - 1)) {
+        }
         ScanMetrics scanMetrics = scanner.getScanMetrics();
         assertEquals("Did not access all the regions in the table", numOfRegions,
                 scanMetrics.countOfRegions.get());