Enable CheckStyle Plugin in Pulsar metadata (apache#13284)

pulsar-metadata/pom.xml

@@ -88,6 +88,19 @@
           </execution>
         </executions>
       </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-checkstyle-plugin</artifactId>
+        <executions>
+          <execution>
+            <id>checkstyle</id>
+            <phase>verify</phase>
+            <goals>
+              <goal>check</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
       <plugin>
         <groupId>com.github.spotbugs</groupId>
         <artifactId>spotbugs-maven-plugin</artifactId>

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/api/MetadataCache.java

@@ -22,7 +22,6 @@
 import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 import java.util.function.Function;
-
 import org.apache.pulsar.metadata.api.MetadataStoreException.AlreadyExistsException;
 import org.apache.pulsar.metadata.api.MetadataStoreException.NotFoundException;
 

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/api/MetadataStore.java

@@ -20,12 +20,10 @@
 
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.google.common.annotations.Beta;
-
 import java.util.List;
 import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 import java.util.function.Consumer;
-
 import org.apache.pulsar.metadata.api.MetadataStoreException.BadVersionException;
 import org.apache.pulsar.metadata.api.MetadataStoreException.NotFoundException;
 

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/api/MetadataStoreConfig.java

@@ -47,25 +47,25 @@ public class MetadataStoreConfig {
     private final String configFilePath = null;
 
     /**
-     * Whether we should enable metadata operations batching
+     * Whether we should enable metadata operations batching.
      */
     @Builder.Default
     private final boolean batchingEnabled = true;
 
     /**
-     * Maximum delay to impose on batching grouping
+     * Maximum delay to impose on batching grouping.
      */
     @Builder.Default
     private final int batchingMaxDelayMillis = 5;
 
     /**
-     * Maximum number of operations to include in a singular batch
+     * Maximum number of operations to include in a singular batch.
      */
     @Builder.Default
     private final int batchingMaxOperations = 1_000;
 
     /**
-     * Maximum size of a batch
+     * Maximum size of a batch.
      */
     @Builder.Default
     private final int batchingMaxSizeKb = 128;

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/api/MetadataStoreException.java

@@ -40,7 +40,7 @@ public MetadataStoreException(String msg, Throwable t) {
     }
 
     /**
-     * Implementation is invalid
+     * Implementation is invalid.
      */
     public static class InvalidImplementationException extends MetadataStoreException {
         public InvalidImplementationException() {

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/api/MetadataStoreFactory.java

@@ -19,9 +19,7 @@
 package org.apache.pulsar.metadata.api;
 
 import java.io.IOException;
-
 import lombok.experimental.UtilityClass;
-
 import org.apache.pulsar.metadata.impl.MetadataStoreFactoryImpl;
 
 /**

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/api/Notification.java

@@ -28,7 +28,7 @@ public final class Notification {
     private final NotificationType type;
 
     /**
-     * Path of the kev/value pair interested by the notification
+     * Path of the kev/value pair interested by the notification.
      */
     private final String path;
 }

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/api/Stat.java

@@ -27,7 +27,7 @@
 public class Stat {
 
     /**
-     * The path of the value
+     * The path of the value.
      */
     final String path;
 
@@ -47,12 +47,12 @@ public class Stat {
     final long modificationTimestamp;
 
     /**
-     * Whether the key-value pair is ephemeral or persistent
+     * Whether the key-value pair is ephemeral or persistent.
      */
     final boolean ephemeral;
 
     /**
-     * Whether the key-value pair had been created within the current "session"
+     * Whether the key-value pair had been created within the current "session".
      */
     final boolean createdBySelf;
 }

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/api/coordination/LeaderElection.java

@@ -35,13 +35,12 @@ public interface LeaderElection<T> extends AutoCloseable {
      * @param proposedValue
      *            the value to set for the leader, in the case this instance succeeds in becoming leader
      * @return a future that will track the completion of the operation
-     * @throws MetadataStoreException
      *             if there's a failure in the leader election
      */
     CompletableFuture<LeaderElectionState> elect(T proposedValue);
 
     /**
-     * Get the current leader election state
+     * Get the current leader election state.
      */
     LeaderElectionState getState();
 

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/api/coordination/LeaderElectionState.java

@@ -23,17 +23,17 @@
  */
 public enum LeaderElectionState {
     /**
-     * No leader has been elected yet
+     * No leader has been elected yet.
      */
     NoLeader,
 
     /**
-     * We are currently the leader
+     * We are currently the leader.
      */
     Leading,
 
     /**
-     * Follower state
+     * Follower state.
      */
     Following
 }

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/api/coordination/LockManager.java

@@ -21,7 +21,6 @@
 import java.util.List;
 import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
-
 import org.apache.pulsar.metadata.api.MetadataStoreException;
 import org.apache.pulsar.metadata.api.MetadataStoreException.LockBusyException;
 import org.apache.pulsar.metadata.api.MetadataStoreException.NotFoundException;
@@ -41,8 +40,6 @@ public interface LockManager<T> extends AutoCloseable {
      *
      * @param path
      *            the path of the resource on which to acquire the lock
-     * @param content
-     *            the payload of the lock
      * @return a future that will track the completion of the operation
      * @throws NotFoundException
      *             if the lock is not taken

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/api/coordination/package-info.java

@@ -0,0 +1,19 @@
+/**
+ * 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.pulsar.metadata.api.coordination;

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/api/extended/CreateOption.java

@@ -19,16 +19,16 @@
 package org.apache.pulsar.metadata.api.extended;
 
 /**
- * Options to use when creating key-value pairs on the {@link MetadataStoreExtended}
+ * Options to use when creating key-value pairs on the {@link MetadataStoreExtended}.
  */
 public enum CreateOption {
     /**
-     * The key-value pair will automatically expires when the session is terminated
+     * The key-value pair will automatically expires when the session is terminated.
      */
     Ephemeral,
 
     /**
-     * Create a sequential unique key
+     * Create a sequential unique key.
      */
     Sequential
 }

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/api/extended/MetadataStoreExtended.java

@@ -22,7 +22,6 @@
 import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 import java.util.function.Consumer;
-
 import org.apache.pulsar.metadata.api.MetadataStore;
 import org.apache.pulsar.metadata.api.MetadataStoreConfig;
 import org.apache.pulsar.metadata.api.MetadataStoreException;

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/api/extended/SessionEvent.java

@@ -19,17 +19,17 @@
 package org.apache.pulsar.metadata.api.extended;
 
 /**
- * An event regarding a session of MetadataStore
+ * An event regarding a session of MetadataStore.
  */
 public enum SessionEvent {
 
     /**
-     * The client is temporarily disconnected, although the session is still valid
+     * The client is temporarily disconnected, although the session is still valid.
      */
     ConnectionLost,
 
     /**
-     * The client was able to successfully reconnect
+     * The client was able to successfully reconnect.
      */
     Reconnected,
 
@@ -40,7 +40,7 @@ public enum SessionEvent {
     SessionLost,
 
     /**
-     * The session was established
+     * The session was established.
      */
     SessionReestablished;
 

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/api/extended/package-info.java

@@ -0,0 +1,19 @@
+/**
+ * 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.pulsar.metadata.api.extended;

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/api/package-info.java

@@ -0,0 +1,19 @@
+/**
+ * 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.pulsar.metadata.api;

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/bookkeeper/AbstractHierarchicalLedgerManager.java

@@ -190,7 +190,8 @@ protected void asyncProcessLedgersInSingleNode(
             final int successRc, final int failureRc) {
         store.getChildren(path)
                 .thenAccept(ledgerNodes -> {
-                    Set<Long> activeLedgers = HierarchicalLedgerUtils.ledgerListToSet(ledgerNodes, ledgerRootPath, path);
+                    Set<Long> activeLedgers = HierarchicalLedgerUtils.ledgerListToSet(ledgerNodes,
+                            ledgerRootPath, path);
                     if (log.isDebugEnabled()) {
                         log.debug("Processing ledgers: {}", activeLedgers);
                     }

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/bookkeeper/BKCluster.java

@@ -29,7 +29,6 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
-import lombok.Cleanup;
 import lombok.Getter;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.bookkeeper.bookie.Bookie;
@@ -303,10 +302,10 @@ public static ClientConfiguration newBaseClientConfiguration() {
     private static String getLoopbackInterfaceName() {
         try {
             Enumeration<NetworkInterface> nifs = NetworkInterface.getNetworkInterfaces();
-            Iterator var1 = Collections.list(nifs).iterator();
+            Iterator<NetworkInterface> var1 = Collections.list(nifs).iterator();
 
-            while(var1.hasNext()) {
-                NetworkInterface nif = (NetworkInterface)var1.next();
+            while (var1.hasNext()) {
+                NetworkInterface nif = var1.next();
                 if (nif.isLoopback()) {
                     return nif.getName();
                 }

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/bookkeeper/BookieServiceInfoSerde.java

@@ -25,7 +25,6 @@
 import lombok.extern.slf4j.Slf4j;
 import org.apache.bookkeeper.discover.BookieServiceInfo;
 import org.apache.bookkeeper.proto.DataFormats.BookieServiceInfoFormat;
-import org.apache.bookkeeper.server.service.BookieService;
 import org.apache.pulsar.metadata.api.MetadataSerde;
 import org.apache.pulsar.metadata.api.Stat;
 

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/bookkeeper/PulsarLedgerManagerFactory.java

@@ -96,7 +96,7 @@ public LedgerAuditorManager newLedgerAuditorManager() throws IOException, Interr
     @Override
     public void format(AbstractConfiguration<?> abstractConfiguration, LayoutManager layoutManager)
             throws InterruptedException, IOException {
-        // TODO: XXX
+        // TODO: format
     }
 
     @Override

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/bookkeeper/PulsarLedgerUnderreplicationManager.java

@@ -56,7 +56,6 @@
 import org.apache.bookkeeper.replication.ReplicationException;
 import org.apache.bookkeeper.util.BookKeeperConstants;
 import org.apache.pulsar.metadata.api.GetResult;
-import org.apache.pulsar.metadata.api.MetadataStore;
 import org.apache.pulsar.metadata.api.MetadataStoreException;
 import org.apache.pulsar.metadata.api.Notification;
 import org.apache.pulsar.metadata.api.NotificationType;

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/bookkeeper/package-info.java

@@ -0,0 +1,19 @@
+/**
+ * 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.pulsar.metadata.bookkeeper;

pulsar-metadata/src/main/java/org/apache/pulsar/metadata/cache/impl/JSONMetadataSerdeTypeRef.java

@@ -19,9 +19,7 @@
 package org.apache.pulsar.metadata.cache.impl;
 
 import com.fasterxml.jackson.core.type.TypeReference;
-
 import java.io.IOException;
-
 import org.apache.pulsar.common.util.ObjectMapperFactory;
 import org.apache.pulsar.metadata.api.MetadataSerde;
 import org.apache.pulsar.metadata.api.Stat;