GH-39712: [Java] Enable code review and formatting code through Spotless Maven plugin

docs/source/developers/java/development.rst

@@ -110,15 +110,67 @@ integration tests, you would do:
 Code Style
 ==========
 
-Code style is enforced with Checkstyle. The configuration is located at `checkstyle`_.
-You can also just check the style without building the project.
-This checks the code style of all source code under the current directory or from within an individual module.
+The current Java code styles are configured as follows:
+
+- Indent: Tabs & spaces (2 spaces per tab)
+- Google Java Format: Reformats Java source code to comply with `Google Java Style`_.
+- Configure license headers for Java & XML files
+
+Java code style is checked by `Spotless`_ during the build, and the continuous integration build will verify
+that changes adhere to the style guide.
+
+.. code-block:: xml
+
+    <java>
+      <indent>
+        ...
+      </indent>
+      <googleJavaFormat/>
+      <licenseHeader>
+        ...
+      </licenseHeader>
+    </java>
+    <pom>
+      <indent>
+        ...
+      </indent>
+      <sortPom>
+        ...
+      </sortPom>
+    </pom>
+
+Automatically fixing code style issues
+--------------------------------------
+
+- You can also just check the style without building the project with `mvn spotless:check`.
+- The Java code style can be corrected from the command line by using the following commands: `mvn spotless:apply`.
+
+.. code-block:: bash
+
+    user@machine repo % mvn spotless:check
+    [ERROR]  > The following files had format violations:
+    [ERROR]  src\main\java\com\diffplug\gradle\spotless\FormatExtension.java
+    [ERROR]    -\t\t····if·(targets.length·==·0)·{
+    [ERROR]    +\t\tif·(targets.length·==·0)·{
+    [ERROR]  Run 'mvn spotless:apply' to fix these violations.
+    user@machine repo % mvn spotless:apply
+    [INFO] BUILD SUCCESS
+    user@machine repo % mvn spotless:check
+    [INFO] BUILD SUCCESS
+
+Code Formatter for Intellij IDEA and Eclipse
+--------------------------------------------
+
+Follow the instructions for:
+
+- `Eclipse`_
+- `IntelliJ`_
 
-.. code-block::
-
-    $ mvn checkstyle:check
 
 .. _benchmark: https://github.com/ursacomputing/benchmarks
 .. _archery: https://github.com/apache/arrow/blob/main/dev/conbench_envs/README.md#L188
 .. _conbench: https://github.com/conbench/conbench
-.. _checkstyle: https://github.com/apache/arrow/blob/main/java/dev/checkstyle/checkstyle.xml
+.. _Spotless: https://github.com/diffplug/spotless
+.. _Google Java Style: https://google.github.io/styleguide/javaguide.html
+.. _Eclipse: https://github.com/google/google-java-format?tab=readme-ov-file#eclipse
+.. _IntelliJ: https://github.com/google/google-java-format?tab=readme-ov-file#intellij-android-studio-and-other-jetbrains-ides

java/.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,18 @@
+# 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.
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.4/apache-maven-3.9.4-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.2.0/maven-wrapper-3.2.0.jar

java/adapter/avro/pom.xml

@@ -1,15 +1,14 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!-- 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. -->
-
+  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. -->
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>
 

java/adapter/avro/src/main/java/org/apache/arrow/adapter/avro/AvroToArrow.java

@@ -18,20 +18,17 @@
 package org.apache.arrow.adapter.avro;
 
 import java.io.IOException;
-
 import org.apache.arrow.util.Preconditions;
 import org.apache.arrow.vector.VectorSchemaRoot;
 import org.apache.avro.Schema;
 import org.apache.avro.io.Decoder;
 
-/**
- * Utility class to convert Avro objects to columnar Arrow format objects.
- */
+/** Utility class to convert Avro objects to columnar Arrow format objects. */
 public class AvroToArrow {
 
   /**
-   * Fetch the data from {@link Decoder} and convert it to Arrow objects.
-   * Only for testing purpose.
+   * Fetch the data from {@link Decoder} and convert it to Arrow objects. Only for testing purpose.
+   *
    * @param schema avro schema.
    * @param decoder avro decoder
    * @param config configuration of the conversion.
@@ -48,15 +45,14 @@ static VectorSchemaRoot avroToArrow(Schema schema, Decoder decoder, AvroToArrowC
 
   /**
    * Fetch the data from {@link Decoder} and iteratively convert it to Arrow objects.
+   *
    * @param schema avro schema
    * @param decoder avro decoder
    * @param config configuration of the conversion.
    * @throws IOException on error
    */
   public static AvroToArrowVectorIterator avroToArrowIterator(
-      Schema schema,
-      Decoder decoder,
-      AvroToArrowConfig config) throws IOException {
+      Schema schema, Decoder decoder, AvroToArrowConfig config) throws IOException {
 
     Preconditions.checkNotNull(schema, "Avro schema object cannot be null");
     Preconditions.checkNotNull(decoder, "Avro decoder object cannot be null");

java/adapter/avro/src/main/java/org/apache/arrow/adapter/avro/AvroToArrowConfig.java

@@ -18,36 +18,33 @@
 package org.apache.arrow.adapter.avro;
 
 import java.util.Set;
-
 import org.apache.arrow.memory.BufferAllocator;
 import org.apache.arrow.util.Preconditions;
 import org.apache.arrow.vector.dictionary.DictionaryProvider;
 
-/**
- * This class configures the Avro-to-Arrow conversion process.
- */
+/** This class configures the Avro-to-Arrow conversion process. */
 public class AvroToArrowConfig {
 
   private final BufferAllocator allocator;
+
   /**
-   * The maximum rowCount to read each time when partially convert data.
-   * Default value is 1024 and -1 means read all data into one vector.
+   * The maximum rowCount to read each time when partially convert data. Default value is 1024 and
+   * -1 means read all data into one vector.
    */
   private final int targetBatchSize;
 
   /**
-   * The dictionary provider used for enum type.
-   * If avro schema has enum type, will create dictionary and update this provider.
+   * The dictionary provider used for enum type. If avro schema has enum type, will create
+   * dictionary and update this provider.
    */
   private final DictionaryProvider.MapDictionaryProvider provider;
 
-  /**
-   * The field names which to skip when reading decoder values.
-   */
+  /** The field names which to skip when reading decoder values. */
   private final Set<String> skipFieldNames;
 
   /**
    * Instantiate an instance.
+   *
    * @param allocator The memory allocator to construct the Arrow vectors with.
    * @param targetBatchSize The maximum rowCount to read each time when partially convert data.
    * @param provider The dictionary provider used for enum type, adapter will update this provider.
@@ -59,8 +56,10 @@ public class AvroToArrowConfig {
       DictionaryProvider.MapDictionaryProvider provider,
       Set<String> skipFieldNames) {
 
-    Preconditions.checkArgument(targetBatchSize == AvroToArrowVectorIterator.NO_LIMIT_BATCH_SIZE ||
-        targetBatchSize > 0, "invalid targetBatchSize: %s", targetBatchSize);
+    Preconditions.checkArgument(
+        targetBatchSize == AvroToArrowVectorIterator.NO_LIMIT_BATCH_SIZE || targetBatchSize > 0,
+        "invalid targetBatchSize: %s",
+        targetBatchSize);
 
     this.allocator = allocator;
     this.targetBatchSize = targetBatchSize;

java/adapter/avro/src/main/java/org/apache/arrow/adapter/avro/AvroToArrowConfigBuilder.java

@@ -19,13 +19,10 @@
 
 import java.util.HashSet;
 import java.util.Set;
-
 import org.apache.arrow.memory.BufferAllocator;
 import org.apache.arrow.vector.dictionary.DictionaryProvider;
 
-/**
- * This class builds {@link AvroToArrowConfig}s.
- */
+/** This class builds {@link AvroToArrowConfig}s. */
 public class AvroToArrowConfigBuilder {
 
   private BufferAllocator allocator;
@@ -36,9 +33,7 @@ public class AvroToArrowConfigBuilder {
 
   private Set<String> skipFieldNames;
 
-  /**
-   * Default constructor for the {@link AvroToArrowConfigBuilder}.
-   */
+  /** Default constructor for the {@link AvroToArrowConfigBuilder}. */
   public AvroToArrowConfigBuilder(BufferAllocator allocator) {
     this.allocator = allocator;
     this.targetBatchSize = AvroToArrowVectorIterator.DEFAULT_BATCH_SIZE;
@@ -61,14 +56,8 @@ public AvroToArrowConfigBuilder setSkipFieldNames(Set<String> skipFieldNames) {
     return this;
   }
 
-  /**
-   * This builds the {@link AvroToArrowConfig} from the provided params.
-   */
+  /** This builds the {@link AvroToArrowConfig} from the provided params. */
   public AvroToArrowConfig build() {
-    return new AvroToArrowConfig(
-        allocator,
-        targetBatchSize,
-        provider,
-        skipFieldNames);
+    return new AvroToArrowConfig(allocator, targetBatchSize, provider, skipFieldNames);
   }
 }