[CheckStyle]Enable CheckStyle of rest of modules of pulsar-functions (a…

…pache#14352)

### Motivation

Enable CheckStyle plugin in 

pulsar-functions-api-example 
pulsar-functions-local-runner-origin 
pulsar-functions-runtime
pulsar-functions-runtime-all
pulsar-functions-utils
pulsar-functions-secrets

### Modifications

Fix the wrong code style

pulsar-functions/java-examples/pom.xml

@@ -72,6 +72,19 @@
           </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>
     </plugins>
   </build>
 

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/AddWindowFunction.java

@@ -18,16 +18,15 @@
  */
 package org.apache.pulsar.functions.api.examples;
 
-import lombok.extern.slf4j.Slf4j;
-
 import java.util.Collection;
 import java.util.function.Function;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * Example Function that acts on a window of tuples at a time rather than per tuple basis.
  */
 @Slf4j
-public class AddWindowFunction implements Function <Collection<Integer>, Integer> {
+public class AddWindowFunction implements Function<Collection<Integer>, Integer> {
     @Override
     public Integer apply(Collection<Integer> integers) {
         return integers.stream().reduce(0, (x, y) -> x + y);

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/AsyncContextFunction.java

@@ -28,24 +28,24 @@
 public class AsyncContextFunction implements Function<String, CompletableFuture<Void>> {
     @Override
     public CompletableFuture<Void> process(String input, Context context) {
-        Logger LOG = context.getLogger();
+        Logger log = context.getLogger();
         CompletableFuture<Void> future = new CompletableFuture();
 
         // this method only delay a function execute.
         Executors.newCachedThreadPool().submit(() -> {
             try {
                 Thread.sleep(500);
             } catch (Exception e) {
-                LOG.error("Exception when Thread.sleep", e);
+                log.error("Exception when Thread.sleep", e);
                 future.completeExceptionally(e);
             }
 
             String inputTopics = context.getInputTopics().stream().collect(Collectors.joining(", "));
             String funcName = context.getFunctionName();
 
-            String logMessage = String.format("A message with value of \"%s\" has arrived on " +
-                    "one of the following topics: %s %n", input, inputTopics);
-            LOG.info(logMessage);
+            String logMessage = String.format("A message with value of \"%s\" has arrived on "
+                    + "one of the following topics: %s %n", input, inputTopics);
+            log.info(logMessage);
 
             String metricName = String.format("function-%s-messages-received", funcName);
             context.recordMetric(metricName, 1);

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/ByteBufferSerDe.java

@@ -18,9 +18,8 @@
  */
 package org.apache.pulsar.functions.api.examples;
 
-import org.apache.pulsar.functions.api.SerDe;
-
 import java.nio.ByteBuffer;
+import org.apache.pulsar.functions.api.SerDe;
 
 /**
  * Simple ByteBuffer Serializer and Deserializer.

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/ConfigBasedAppendFunction.java

@@ -18,11 +18,10 @@
  */
 package org.apache.pulsar.functions.api.examples;
 
+import java.util.Optional;
 import org.apache.pulsar.functions.api.Context;
 import org.apache.pulsar.functions.api.Function;
 
-import java.util.Optional;
-
 /**
  * Function that appends something to incoming input based on config supplied.
  */

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/ContextFunction.java

@@ -18,23 +18,22 @@
  */
 package org.apache.pulsar.functions.api.examples;
 
+import java.util.stream.Collectors;
 import org.apache.pulsar.functions.api.Context;
 import org.apache.pulsar.functions.api.Function;
 import org.slf4j.Logger;
 
-import java.util.stream.Collectors;
-
 public class ContextFunction implements Function<String, Void> {
     @Override
     public Void process(String input, Context context) {
-        Logger LOG = context.getLogger();
+        Logger log = context.getLogger();
         String inputTopics = context.getInputTopics().stream().collect(Collectors.joining(", "));
         String functionName = context.getFunctionName();
 
-        String logMessage = String.format("A message with a value of \"%s\" has arrived on one of " +
-                "the following topics: %s %n", input, inputTopics);
+        String logMessage = String.format("A message with a value of \"%s\" has arrived on one of "
+                + "the following topics: %s %n", input, inputTopics);
 
-        LOG.info(logMessage);
+        log.info(logMessage);
 
         String metricName = String.format("function-%s-messages-received", functionName);
         context.recordMetric(metricName, 1);

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/CursorManagementFunction.java

@@ -34,8 +34,8 @@ public class CursorManagementFunction implements Function<String, String> {
     public String process(String input, Context context) throws Exception {
         PulsarAdmin adminClient = context.getPulsarAdmin();
         if (adminClient != null) {
-            String topic = context.getCurrentRecord().getTopicName().isPresent() ?
-                    context.getCurrentRecord().getTopicName().get() : null;
+            String topic = context.getCurrentRecord().getTopicName().isPresent()
+                    ? context.getCurrentRecord().getTopicName().get() : null;
             String subName = context.getTenant() + "/" + context.getNamespace() + "/" + context.getFunctionName();
             if (topic != null) {
                 // 1578188166 below is a random-pick timestamp

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/CustomBaseSerde.java

@@ -18,17 +18,16 @@
  */
 package org.apache.pulsar.functions.api.examples;
 
-import org.apache.pulsar.functions.api.SerDe;
-
 import java.nio.ByteBuffer;
+import org.apache.pulsar.functions.api.SerDe;
 
 /**
  * Example of using a byte buffer serialization for Custom object.
  */
 public class CustomBaseSerde implements SerDe<CustomBaseObject> {
     @Override
     public CustomBaseObject deserialize(byte[] bytes) {
-        ByteBuffer buffer =  ByteBuffer.wrap(bytes);
+        ByteBuffer buffer = ByteBuffer.wrap(bytes);
         return new CustomBaseObject(buffer.getLong());
     }
 

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/CustomBaseToDerivedFunction.java

@@ -28,7 +28,8 @@ public class CustomBaseToDerivedFunction implements Function<CustomBaseObject, C
 
     @Override
     public CustomDerivedObject process(CustomBaseObject input, Context context) {
-        return new CustomDerivedObject(input.getBaseValue() + 100, (int)input.getBaseValue() + 50);
+        return new CustomDerivedObject(input.getBaseValue() + 100,
+                (int) input.getBaseValue() + 50);
     }
 }
 

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/CustomDerivedSerde.java

@@ -18,17 +18,16 @@
  */
 package org.apache.pulsar.functions.api.examples;
 
-import org.apache.pulsar.functions.api.SerDe;
-
 import java.nio.ByteBuffer;
+import org.apache.pulsar.functions.api.SerDe;
 
 /**
  *  Example to derived object serialization.
  */
 public class CustomDerivedSerde implements SerDe<CustomDerivedObject> {
     @Override
     public CustomDerivedObject deserialize(byte[] bytes) {
-        ByteBuffer buffer =  ByteBuffer.wrap(bytes);
+        ByteBuffer buffer = ByteBuffer.wrap(bytes);
         return new CustomDerivedObject(buffer.getLong(), buffer.getInt());
     }
 

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/HostAppenderFunction.java

@@ -18,11 +18,10 @@
  */
 package org.apache.pulsar.functions.api.examples;
 
-import org.apache.pulsar.functions.api.Context;
-import org.apache.pulsar.functions.api.Function;
-
 import java.net.InetAddress;
 import java.net.UnknownHostException;
+import org.apache.pulsar.functions.api.Context;
+import org.apache.pulsar.functions.api.Function;
 
 /**
  * Function that appends the host name to the payload message.

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/RawFileKeyReader.java

@@ -16,21 +16,19 @@
  * specific language governing permissions and limitations
  * under the License.
  */
-
 package org.apache.pulsar.functions.api.examples;
 
-import lombok.Data;
-import org.apache.pulsar.client.api.CryptoKeyReader;
-import org.apache.pulsar.client.api.EncryptionKeyInfo;
-
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.Map;
+import lombok.Data;
+import org.apache.pulsar.client.api.CryptoKeyReader;
+import org.apache.pulsar.client.api.EncryptionKeyInfo;
 
 /**
  * Example function that provide a constructor with map<string, object> argument
- * to initialize the CryptoKeyReader class used by pulsar function
+ * to initialize the CryptoKeyReader class used by pulsar function.
  */
 @Data
 public class RawFileKeyReader implements CryptoKeyReader {

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/TypedMessageBuilderPublish.java

@@ -18,15 +18,14 @@
  */
 package org.apache.pulsar.functions.api.examples;
 
+import java.util.HashMap;
+import java.util.Map;
 import org.apache.pulsar.client.api.PulsarClientException;
 import org.apache.pulsar.client.api.Schema;
 import org.apache.pulsar.client.api.TypedMessageBuilder;
 import org.apache.pulsar.functions.api.Context;
 import org.apache.pulsar.functions.api.Function;
 
-import java.util.HashMap;
-import java.util.Map;
-
 /**
  * Example function that uses the built in publish function in the context
  * to publish to a desired topic based on config and setting various message configurations to be passed along.
@@ -45,7 +44,7 @@ public Void process(String input, Context context) {
         try {
             TypedMessageBuilder messageBuilder = context.newOutputMessage(publishTopic, Schema.STRING).
                     value(output).properties(properties);
-            if (context.getCurrentRecord().getKey().isPresent()){
+            if (context.getCurrentRecord().getKey().isPresent()) {
                 messageBuilder.key(context.getCurrentRecord().getKey().get());
             }
             messageBuilder.eventTime(System.currentTimeMillis()).sendAsync();

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/UserConfigFunction.java

@@ -18,11 +18,10 @@
  */
 package org.apache.pulsar.functions.api.examples;
 
+import java.util.Optional;
 import org.apache.pulsar.functions.api.Context;
 import org.apache.pulsar.functions.api.Function;
 
-import java.util.Optional;
-
 /**
  * An example demonstrate retrieving user config value from Context.
  */
@@ -32,7 +31,7 @@ public class UserConfigFunction implements Function<String, String> {
     public String process(String input, Context context) {
         Optional<Object> whatToWrite = context.getUserConfigValue("WhatToWrite");
         if (whatToWrite.get() != null) {
-            return (String)whatToWrite.get();
+            return (String) whatToWrite.get();
         } else {
             return "Not a nice way";
         }

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/UserPublishFunction.java

@@ -19,7 +19,6 @@
 package org.apache.pulsar.functions.api.examples;
 
 import java.util.Optional;
-
 import org.apache.pulsar.client.api.PulsarClientException;
 import org.apache.pulsar.client.api.Schema;
 import org.apache.pulsar.functions.api.Context;

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/VoidFunction.java

@@ -22,7 +22,7 @@
 import org.apache.pulsar.functions.api.Function;
 
 /**
- * Example function that does not return any value
+ * Example function that does not return any value.
  */
 public class VoidFunction implements Function<String, Void> {
     @Override

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/WordCountFunction.java

@@ -18,11 +18,10 @@
  */
 package org.apache.pulsar.functions.api.examples;
 
+import java.util.Arrays;
 import org.apache.pulsar.functions.api.Context;
 import org.apache.pulsar.functions.api.Function;
 
-import java.util.Arrays;
-
 /**
  * The classic word count example done using pulsar functions
  * Each input message is a sentence that split into words and each word counted.

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

@@ -0,0 +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.pulsar.functions.api.examples;

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/pojo/package-info.java

@@ -0,0 +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.pulsar.functions.api.examples.pojo;

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/serde/CustomObjectSerde.java

@@ -18,17 +18,16 @@
  */
 package org.apache.pulsar.functions.api.examples.serde;
 
-import org.apache.pulsar.functions.api.SerDe;
-
 import java.nio.ByteBuffer;
+import org.apache.pulsar.functions.api.SerDe;
 
 /**
  * This class takes care of serializing/deserializing CustomObject.
  */
 public class CustomObjectSerde implements SerDe<CustomObject> {
     @Override
     public CustomObject deserialize(byte[] bytes) {
-        ByteBuffer buffer =  ByteBuffer.wrap(bytes);
+        ByteBuffer buffer = ByteBuffer.wrap(bytes);
         return new CustomObject(buffer.getLong());
     }
 

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/serde/package-info.java

@@ -0,0 +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.pulsar.functions.api.examples.serde;

pulsar-functions/java-examples/src/main/java/org/apache/pulsar/functions/api/examples/window/ContextWindowFunction.java

@@ -18,13 +18,12 @@
  */
 package org.apache.pulsar.functions.api.examples.window;
 
+import java.util.Collection;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.pulsar.functions.api.Record;
 import org.apache.pulsar.functions.api.WindowContext;
 import org.apache.pulsar.functions.api.WindowFunction;
 
-import java.util.Collection;
-
 /**
  * Example Function that acts on a window of tuples at a time rather than per tuple basis.
  */