[SPARK-13583][CORE][STREAMING] Remove unused imports and add checksty…

…le rule ## What changes were proposed in this pull request? After SPARK-6990, `dev/lint-java` keeps Java code healthy and helps PR review by saving much time. This issue aims remove unused imports from Java/Scala code and add `UnusedImports` checkstyle rule to help developers. ## How was this patch tested? ``` ./dev/lint-java ./build/sbt compile ``` Author: Dongjoon Hyun <dongjoon@apache.org> Closes #11438 from dongjoon-hyun/SPARK-13583.
apache · Mar 3, 2016 · b5f02d6 · b5f02d6
1 parent e97fc7f
commit b5f02d6
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Showing 226 changed files with 103 additions and 337 deletions.
diff --git a/checkstyle.xml b/checkstyle.xml
@@ -166,5 +166,6 @@
             <property name="exceptionVariableName" value="expected"/>
         </module>
         <module name="CommentsIndentation"/>
+        <module name="UnusedImports"/>
     </module>
 </module>
diff --git a/common/network-common/src/main/java/org/apache/spark/network/protocol/OneWayMessage.java b/common/network-common/src/main/java/org/apache/spark/network/protocol/OneWayMessage.java
@@ -19,7 +19,6 @@
 
 import com.google.common.base.Objects;
 import io.netty.buffer.ByteBuf;
-import io.netty.buffer.Unpooled;
 
 import org.apache.spark.network.buffer.ManagedBuffer;
 import org.apache.spark.network.buffer.NettyManagedBuffer;

diff --git a/common/network-common/src/main/java/org/apache/spark/network/protocol/RpcRequest.java b/common/network-common/src/main/java/org/apache/spark/network/protocol/RpcRequest.java
@@ -19,7 +19,6 @@
 
 import com.google.common.base.Objects;
 import io.netty.buffer.ByteBuf;
-import io.netty.buffer.Unpooled;
 
 import org.apache.spark.network.buffer.ManagedBuffer;
 import org.apache.spark.network.buffer.NettyManagedBuffer;

diff --git a/common/network-common/src/main/java/org/apache/spark/network/protocol/RpcResponse.java b/common/network-common/src/main/java/org/apache/spark/network/protocol/RpcResponse.java
@@ -19,7 +19,6 @@
 
 import com.google.common.base.Objects;
 import io.netty.buffer.ByteBuf;
-import io.netty.buffer.Unpooled;
 
 import org.apache.spark.network.buffer.ManagedBuffer;
 import org.apache.spark.network.buffer.NettyManagedBuffer;

diff --git a/common/network-common/src/main/java/org/apache/spark/network/protocol/StreamFailure.java b/common/network-common/src/main/java/org/apache/spark/network/protocol/StreamFailure.java
@@ -20,9 +20,6 @@
 import com.google.common.base.Objects;
 import io.netty.buffer.ByteBuf;
 
-import org.apache.spark.network.buffer.ManagedBuffer;
-import org.apache.spark.network.buffer.NettyManagedBuffer;
-
 /**
  * Message indicating an error when transferring a stream.
  */

diff --git a/common/network-common/src/main/java/org/apache/spark/network/protocol/StreamRequest.java b/common/network-common/src/main/java/org/apache/spark/network/protocol/StreamRequest.java
@@ -20,9 +20,6 @@
 import com.google.common.base.Objects;
 import io.netty.buffer.ByteBuf;
 
-import org.apache.spark.network.buffer.ManagedBuffer;
-import org.apache.spark.network.buffer.NettyManagedBuffer;
-
 /**
  * Request to stream data from the remote end.
  * <p>

diff --git a/common/network-common/src/main/java/org/apache/spark/network/protocol/StreamResponse.java b/common/network-common/src/main/java/org/apache/spark/network/protocol/StreamResponse.java
@@ -21,7 +21,6 @@
 import io.netty.buffer.ByteBuf;
 
 import org.apache.spark.network.buffer.ManagedBuffer;
-import org.apache.spark.network.buffer.NettyManagedBuffer;
 
 /**
  * Response to {@link StreamRequest} when the stream has been successfully opened.

diff --git a/common/network-common/src/main/java/org/apache/spark/network/sasl/SaslEncryption.java b/common/network-common/src/main/java/org/apache/spark/network/sasl/SaslEncryption.java
@@ -33,7 +33,6 @@
 import io.netty.channel.FileRegion;
 import io.netty.handler.codec.MessageToMessageDecoder;
 import io.netty.util.AbstractReferenceCounted;
-import io.netty.util.ReferenceCountUtil;
 
 import org.apache.spark.network.util.ByteArrayWritableChannel;
 import org.apache.spark.network.util.NettyUtils;

diff --git a/...network-common/src/main/java/org/apache/spark/network/server/TransportRequestHandler.java b/...network-common/src/main/java/org/apache/spark/network/server/TransportRequestHandler.java
@@ -19,7 +19,6 @@
 
 import java.nio.ByteBuffer;
 
-import com.google.common.base.Preconditions;
 import com.google.common.base.Throwables;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;

diff --git a/common/network-common/src/main/java/org/apache/spark/network/util/NettyUtils.java b/common/network-common/src/main/java/org/apache/spark/network/util/NettyUtils.java
@@ -31,8 +31,6 @@
 import io.netty.channel.nio.NioEventLoopGroup;
 import io.netty.channel.socket.nio.NioServerSocketChannel;
 import io.netty.channel.socket.nio.NioSocketChannel;
-import io.netty.handler.codec.ByteToMessageDecoder;
-import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
 import io.netty.util.internal.PlatformDependent;
 
 /**

diff --git a/common/network-common/src/main/java/org/apache/spark/network/util/TransportFrameDecoder.java b/common/network-common/src/main/java/org/apache/spark/network/util/TransportFrameDecoder.java
@@ -17,7 +17,6 @@
 
 package org.apache.spark.network.util;
 
-import java.util.Iterator;
 import java.util.LinkedList;
 
 import com.google.common.base.Preconditions;

diff --git a/common/network-shuffle/src/main/java/org/apache/spark/network/sasl/ShuffleSecretManager.java b/common/network-shuffle/src/main/java/org/apache/spark/network/sasl/ShuffleSecretManager.java
@@ -24,7 +24,6 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import org.apache.spark.network.sasl.SecretKeyHolder;
 import org.apache.spark.network.util.JavaUtils;
 
 /**

diff --git a/...-shuffle/src/test/java/org/apache/spark/network/shuffle/ExternalShuffleSecuritySuite.java b/...-shuffle/src/test/java/org/apache/spark/network/shuffle/ExternalShuffleSecuritySuite.java
@@ -30,7 +30,6 @@
 import org.apache.spark.network.TransportContext;
 import org.apache.spark.network.sasl.SaslServerBootstrap;
 import org.apache.spark.network.sasl.SecretKeyHolder;
-import org.apache.spark.network.server.RpcHandler;
 import org.apache.spark.network.server.TransportServer;
 import org.apache.spark.network.server.TransportServerBootstrap;
 import org.apache.spark.network.shuffle.protocol.ExecutorShuffleInfo;

diff --git a/core/src/main/java/org/apache/spark/shuffle/sort/PackedRecordPointer.java b/core/src/main/java/org/apache/spark/shuffle/sort/PackedRecordPointer.java
@@ -17,8 +17,6 @@
 
 package org.apache.spark.shuffle.sort;
 
-import org.apache.spark.memory.TaskMemoryManager;
-
 /**
  * Wrapper around an 8-byte word that holds a 24-bit partition number and 40-bit record pointer.
  * <p>
@@ -28,7 +26,7 @@
  * </pre>
  * This implies that the maximum addressable page size is 2^27 bits = 128 megabytes, assuming that
  * our offsets in pages are not 8-byte-word-aligned. Since we have 2^13 pages (based off the
- * 13-bit page numbers assigned by {@link TaskMemoryManager}), this
+ * 13-bit page numbers assigned by {@link org.apache.spark.memory.TaskMemoryManager}), this
  * implies that we can address 2^13 * 128 megabytes = 1 terabyte of RAM per task.
  * <p>
  * Assuming word-alignment would allow for a 1 gigabyte maximum page size, but we leave this

diff --git a/core/src/main/java/org/apache/spark/shuffle/sort/UnsafeShuffleWriter.java b/core/src/main/java/org/apache/spark/shuffle/sort/UnsafeShuffleWriter.java
@@ -25,7 +25,6 @@
 import scala.Option;
 import scala.Product2;
 import scala.collection.JavaConverters;
-import scala.collection.immutable.Map;
 import scala.reflect.ClassTag;
 import scala.reflect.ClassTag$;
 

diff --git a/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/PrefixComparators.java b/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/PrefixComparators.java
@@ -20,7 +20,6 @@
 import com.google.common.primitives.UnsignedLongs;
 
 import org.apache.spark.annotation.Private;
-import org.apache.spark.unsafe.Platform;
 import org.apache.spark.unsafe.types.ByteArray;
 import org.apache.spark.unsafe.types.UTF8String;
 import org.apache.spark.util.Utils;

diff --git a/...src/main/java/org/apache/spark/util/collection/unsafe/sort/RecordPointerAndKeyPrefix.java b/...src/main/java/org/apache/spark/util/collection/unsafe/sort/RecordPointerAndKeyPrefix.java
@@ -17,11 +17,9 @@
 
 package org.apache.spark.util.collection.unsafe.sort;
 
-import org.apache.spark.memory.TaskMemoryManager;
-
 final class RecordPointerAndKeyPrefix {
   /**
-   * A pointer to a record; see {@link TaskMemoryManager} for a
+   * A pointer to a record; see {@link org.apache.spark.memory.TaskMemoryManager} for a
    * description of how these addresses are encoded.
    */
   public long recordPointer;

diff --git a/core/src/main/scala/org/apache/spark/ExecutorAllocationManager.scala b/core/src/main/scala/org/apache/spark/ExecutorAllocationManager.scala
@@ -26,7 +26,7 @@ import com.codahale.metrics.{Gauge, MetricRegistry}
 
 import org.apache.spark.metrics.source.Source
 import org.apache.spark.scheduler._
-import org.apache.spark.util.{Clock, SystemClock, ThreadUtils, Utils}
+import org.apache.spark.util.{Clock, SystemClock, ThreadUtils}
 
 /**
  * An agent that dynamically allocates and removes executors based on the workload.

diff --git a/core/src/main/scala/org/apache/spark/HeartbeatReceiver.scala b/core/src/main/scala/org/apache/spark/HeartbeatReceiver.scala
@@ -22,7 +22,6 @@ import java.util.concurrent.{ScheduledFuture, TimeUnit}
 import scala.collection.mutable
 import scala.concurrent.Future
 
-import org.apache.spark.executor.TaskMetrics
 import org.apache.spark.rpc.{RpcCallContext, RpcEnv, ThreadSafeRpcEndpoint}
 import org.apache.spark.scheduler._
 import org.apache.spark.storage.BlockManagerId

diff --git a/core/src/main/scala/org/apache/spark/Partitioner.scala b/core/src/main/scala/org/apache/spark/Partitioner.scala
@@ -21,13 +21,13 @@ import java.io.{IOException, ObjectInputStream, ObjectOutputStream}
 
 import scala.collection.mutable
 import scala.collection.mutable.ArrayBuffer
-import scala.reflect.{classTag, ClassTag}
+import scala.reflect.ClassTag
 import scala.util.hashing.byteswap32
 
 import org.apache.spark.rdd.{PartitionPruningRDD, RDD}
 import org.apache.spark.serializer.JavaSerializer
 import org.apache.spark.util.{CollectionsUtils, Utils}
-import org.apache.spark.util.random.{SamplingUtils, XORShiftRandom}
+import org.apache.spark.util.random.SamplingUtils
 
 /**
  * An object that defines how the elements in a key-value pair RDD are partitioned by key.

diff --git a/core/src/main/scala/org/apache/spark/SparkContext.scala b/core/src/main/scala/org/apache/spark/SparkContext.scala
@@ -51,7 +51,6 @@ import org.apache.spark.deploy.{LocalSparkCluster, SparkHadoopUtil}
 import org.apache.spark.input.{FixedLengthBinaryInputFormat, PortableDataStream, StreamInputFormat,
   WholeTextFileInputFormat}
 import org.apache.spark.io.CompressionCodec
-import org.apache.spark.metrics.MetricsSystem
 import org.apache.spark.partial.{ApproximateEvaluator, PartialResult}
 import org.apache.spark.rdd._
 import org.apache.spark.rpc.RpcEndpointRef

diff --git a/core/src/main/scala/org/apache/spark/TaskNotSerializableException.scala b/core/src/main/scala/org/apache/spark/TaskNotSerializableException.scala
@@ -17,8 +17,6 @@
 
 package org.apache.spark
 
-import org.apache.spark.annotation.DeveloperApi
-
 /**
  * Exception thrown when a task cannot be serialized.
  */

diff --git a/core/src/main/scala/org/apache/spark/api/java/JavaRDD.scala b/core/src/main/scala/org/apache/spark/api/java/JavaRDD.scala
@@ -17,8 +17,6 @@
 
 package org.apache.spark.api.java
 
-import java.util.Comparator
-
 import scala.language.implicitConversions
 import scala.reflect.ClassTag
 
@@ -191,7 +189,6 @@ class JavaRDD[T](val rdd: RDD[T])(implicit val classTag: ClassTag[T])
    * Return this RDD sorted by the given key function.
    */
   def sortBy[S](f: JFunction[T, S], ascending: Boolean, numPartitions: Int): JavaRDD[T] = {
-    import scala.collection.JavaConverters._
     def fn: (T) => S = (x: T) => f.call(x)
     import com.google.common.collect.Ordering  // shadows scala.math.Ordering
     implicit val ordering = Ordering.natural().asInstanceOf[Ordering[S]]

diff --git a/core/src/main/scala/org/apache/spark/broadcast/BroadcastFactory.scala b/core/src/main/scala/org/apache/spark/broadcast/BroadcastFactory.scala
@@ -21,7 +21,6 @@ import scala.reflect.ClassTag
 
 import org.apache.spark.SecurityManager
 import org.apache.spark.SparkConf
-import org.apache.spark.annotation.DeveloperApi
 
 /**
  * An interface for all the broadcast implementations in Spark (to allow

diff --git a/core/src/main/scala/org/apache/spark/deploy/RPackageUtils.scala b/core/src/main/scala/org/apache/spark/deploy/RPackageUtils.scala
@@ -26,7 +26,7 @@ import scala.collection.JavaConverters._
 
 import com.google.common.io.{ByteStreams, Files}
 
-import org.apache.spark.{Logging, SparkException}
+import org.apache.spark.Logging
 import org.apache.spark.api.r.RUtils
 import org.apache.spark.util.{RedirectThread, Utils}
 

diff --git a/core/src/main/scala/org/apache/spark/deploy/master/DriverInfo.scala b/core/src/main/scala/org/apache/spark/deploy/master/DriverInfo.scala
@@ -19,7 +19,6 @@ package org.apache.spark.deploy.master
 
 import java.util.Date
 
-import org.apache.spark.annotation.DeveloperApi
 import org.apache.spark.deploy.DriverDescription
 import org.apache.spark.util.Utils
 

diff --git a/core/src/main/scala/org/apache/spark/deploy/worker/Worker.scala b/core/src/main/scala/org/apache/spark/deploy/worker/Worker.scala
@@ -37,7 +37,7 @@ import org.apache.spark.deploy.master.{DriverState, Master}
 import org.apache.spark.deploy.worker.ui.WorkerWebUI
 import org.apache.spark.metrics.MetricsSystem
 import org.apache.spark.rpc._
-import org.apache.spark.util.{SignalLogger, ThreadUtils, Utils}
+import org.apache.spark.util.{ThreadUtils, Utils}
 
 private[deploy] class Worker(
     override val rpcEnv: RpcEnv,

diff --git a/core/src/main/scala/org/apache/spark/deploy/worker/ui/LogPage.scala b/core/src/main/scala/org/apache/spark/deploy/worker/ui/LogPage.scala
@@ -18,7 +18,6 @@
 package org.apache.spark.deploy.worker.ui
 
 import java.io.File
-import java.net.URI
 import javax.servlet.http.HttpServletRequest
 
 import scala.xml.Node

diff --git a/core/src/main/scala/org/apache/spark/rdd/DoubleRDDFunctions.scala b/core/src/main/scala/org/apache/spark/rdd/DoubleRDDFunctions.scala
@@ -18,7 +18,6 @@
 package org.apache.spark.rdd
 
 import org.apache.spark.{Logging, TaskContext}
-import org.apache.spark.annotation.Experimental
 import org.apache.spark.partial.BoundedDouble
 import org.apache.spark.partial.MeanEvaluator
 import org.apache.spark.partial.PartialResult

diff --git a/core/src/main/scala/org/apache/spark/rdd/JdbcRDD.scala b/core/src/main/scala/org/apache/spark/rdd/JdbcRDD.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.rdd
 
-import java.sql.{Connection, PreparedStatement, ResultSet}
+import java.sql.{Connection, ResultSet}
 
 import scala.reflect.ClassTag
 

diff --git a/core/src/main/scala/org/apache/spark/rdd/LocalCheckpointRDD.scala b/core/src/main/scala/org/apache/spark/rdd/LocalCheckpointRDD.scala
@@ -19,7 +19,7 @@ package org.apache.spark.rdd
 
 import scala.reflect.ClassTag
 
-import org.apache.spark.{Partition, SparkContext, SparkEnv, SparkException, TaskContext}
+import org.apache.spark.{Partition, SparkContext, SparkException, TaskContext}
 import org.apache.spark.storage.RDDBlockId
 
 /**

diff --git a/core/src/main/scala/org/apache/spark/rdd/ReliableRDDCheckpointData.scala b/core/src/main/scala/org/apache/spark/rdd/ReliableRDDCheckpointData.scala
@@ -22,7 +22,6 @@ import scala.reflect.ClassTag
 import org.apache.hadoop.fs.Path
 
 import org.apache.spark._
-import org.apache.spark.util.SerializableConfiguration
 
 /**
  * An implementation of checkpointing that writes the RDD data to reliable storage.

diff --git a/core/src/main/scala/org/apache/spark/rpc/netty/NettyRpcEnv.scala b/core/src/main/scala/org/apache/spark/rpc/netty/NettyRpcEnv.scala
@@ -17,7 +17,6 @@
 package org.apache.spark.rpc.netty
 
 import java.io._
-import java.lang.{Boolean => JBoolean}
 import java.net.{InetSocketAddress, URI}
 import java.nio.ByteBuffer
 import java.nio.channels.{Pipe, ReadableByteChannel, WritableByteChannel}

diff --git a/core/src/main/scala/org/apache/spark/scheduler/ActiveJob.scala b/core/src/main/scala/org/apache/spark/scheduler/ActiveJob.scala
@@ -19,7 +19,6 @@ package org.apache.spark.scheduler
 
 import java.util.Properties
 
-import org.apache.spark.TaskContext
 import org.apache.spark.util.CallSite
 
 /**

diff --git a/core/src/main/scala/org/apache/spark/scheduler/DAGSchedulerEvent.scala b/core/src/main/scala/org/apache/spark/scheduler/DAGSchedulerEvent.scala
@@ -19,11 +19,9 @@ package org.apache.spark.scheduler
 
 import java.util.Properties
 
-import scala.collection.Map
 import scala.language.existentials
 
 import org.apache.spark._
-import org.apache.spark.executor.TaskMetrics
 import org.apache.spark.rdd.RDD
 import org.apache.spark.util.CallSite
 

diff --git a/core/src/main/scala/org/apache/spark/scheduler/TaskScheduler.scala b/core/src/main/scala/org/apache/spark/scheduler/TaskScheduler.scala
@@ -17,7 +17,6 @@
 
 package org.apache.spark.scheduler
 
-import org.apache.spark.executor.TaskMetrics
 import org.apache.spark.scheduler.SchedulingMode.SchedulingMode
 import org.apache.spark.storage.BlockManagerId
 

diff --git a/core/src/main/scala/org/apache/spark/scheduler/cluster/CoarseGrainedClusterMessage.scala b/core/src/main/scala/org/apache/spark/scheduler/cluster/CoarseGrainedClusterMessage.scala
@@ -22,7 +22,7 @@ import java.nio.ByteBuffer
 import org.apache.spark.TaskState.TaskState
 import org.apache.spark.rpc.RpcEndpointRef
 import org.apache.spark.scheduler.ExecutorLossReason
-import org.apache.spark.util.{SerializableBuffer, Utils}
+import org.apache.spark.util.SerializableBuffer
 
 private[spark] sealed trait CoarseGrainedClusterMessage extends Serializable
 

diff --git a/core/src/main/scala/org/apache/spark/serializer/Serializer.scala b/core/src/main/scala/org/apache/spark/serializer/Serializer.scala
@@ -23,9 +23,9 @@ import javax.annotation.concurrent.NotThreadSafe
 
 import scala.reflect.ClassTag
 
-import org.apache.spark.{SparkConf, SparkEnv}
+import org.apache.spark.SparkEnv
 import org.apache.spark.annotation.{DeveloperApi, Private}
-import org.apache.spark.util.{ByteBufferInputStream, NextIterator, Utils}
+import org.apache.spark.util.NextIterator
 
 /**
  * :: DeveloperApi ::

diff --git a/core/src/main/scala/org/apache/spark/shuffle/BaseShuffleHandle.scala b/core/src/main/scala/org/apache/spark/shuffle/BaseShuffleHandle.scala
@@ -17,8 +17,7 @@
 
 package org.apache.spark.shuffle
 
-import org.apache.spark.{Aggregator, Partitioner, ShuffleDependency}
-import org.apache.spark.serializer.Serializer
+import org.apache.spark.ShuffleDependency
 
 /**
  * A basic ShuffleHandle implementation that just captures registerShuffle's parameters.

diff --git a/core/src/main/scala/org/apache/spark/shuffle/ShuffleBlockResolver.scala b/core/src/main/scala/org/apache/spark/shuffle/ShuffleBlockResolver.scala
@@ -17,8 +17,6 @@
 
 package org.apache.spark.shuffle
 
-import java.nio.ByteBuffer
-
 import org.apache.spark.network.buffer.ManagedBuffer
 import org.apache.spark.storage.ShuffleBlockId
 

diff --git a/core/src/main/scala/org/apache/spark/shuffle/hash/HashShuffleWriter.scala b/core/src/main/scala/org/apache/spark/shuffle/hash/HashShuffleWriter.scala
@@ -20,7 +20,6 @@ package org.apache.spark.shuffle.hash
 import java.io.IOException
 
 import org.apache.spark._
-import org.apache.spark.executor.ShuffleWriteMetrics
 import org.apache.spark.scheduler.MapStatus
 import org.apache.spark.serializer.Serializer
 import org.apache.spark.shuffle._

diff --git a/core/src/main/scala/org/apache/spark/shuffle/sort/SortShuffleWriter.scala b/core/src/main/scala/org/apache/spark/shuffle/sort/SortShuffleWriter.scala
@@ -18,7 +18,6 @@
 package org.apache.spark.shuffle.sort
 
 import org.apache.spark._
-import org.apache.spark.executor.ShuffleWriteMetrics
 import org.apache.spark.scheduler.MapStatus
 import org.apache.spark.shuffle.{BaseShuffleHandle, IndexShuffleBlockResolver, ShuffleWriter}
 import org.apache.spark.storage.ShuffleBlockId

diff --git a/core/src/main/scala/org/apache/spark/storage/BlockManagerMaster.scala b/core/src/main/scala/org/apache/spark/storage/BlockManagerMaster.scala
@@ -19,7 +19,7 @@ package org.apache.spark.storage
 
 import scala.collection.Iterable
 import scala.collection.generic.CanBuildFrom
-import scala.concurrent.{Await, Future}
+import scala.concurrent.Future
 
 import org.apache.spark.{Logging, SparkConf, SparkException}
 import org.apache.spark.rpc.RpcEndpointRef