[SPARK-13583][CORE][STREAMING] Remove unused imports and add checkstyle 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.

54 files changed, 28 insertions, 71 deletions

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/Row.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/Row.scala
index b14c66cc5a..f108264861 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/Row.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/Row.scala
@@ -20,7 +20,6 @@ package org.apache.spark.sql
 import scala.collection.JavaConverters._
 import scala.util.hashing.MurmurHash3
 
-import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.catalyst.expressions.GenericRow
 import org.apache.spark.sql.types.StructType
 
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/encoders/package.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/encoders/package.scala
index 9e283f5eb6..03708fb7af 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/encoders/package.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/encoders/package.scala
@@ -18,7 +18,6 @@
 package org.apache.spark.sql.catalyst
 
 import org.apache.spark.sql.Encoder
-import org.apache.spark.sql.catalyst.expressions.AttributeReference
 
 package object encoders {
   /**
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/ExpectsInputTypes.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/ExpectsInputTypes.scala
index c7be8e886c..b3dfac806f 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/ExpectsInputTypes.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/ExpectsInputTypes.scala
@@ -17,7 +17,6 @@
 
 package org.apache.spark.sql.catalyst.expressions
 
-import org.apache.spark.sql.catalyst.analysis.HiveTypeCoercion.ImplicitTypeCasts
 import org.apache.spark.sql.catalyst.analysis.TypeCheckResult
 import org.apache.spark.sql.types.AbstractDataType
 
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/GenerateMutableProjection.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/GenerateMutableProjection.scala
index 9abe92b1e7..7f840890f8 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/GenerateMutableProjection.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/GenerateMutableProjection.scala
@@ -19,7 +19,6 @@ package org.apache.spark.sql.catalyst.expressions.codegen
 
 import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.catalyst.expressions.aggregate.NoOp
-import org.apache.spark.sql.types.DecimalType
 
 // MutableProjection is not accessible in Java
 abstract class BaseMutableProjection extends MutableProjection
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/QueryPlan.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/QueryPlan.scala
index a74b288cb2..3ff37fffbd 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/QueryPlan.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/QueryPlan.scala
@@ -18,7 +18,6 @@
 package org.apache.spark.sql.catalyst.plans
 
 import org.apache.spark.sql.catalyst.expressions._
-import org.apache.spark.sql.catalyst.plans.logical.SubqueryAlias
 import org.apache.spark.sql.catalyst.trees.TreeNode
 import org.apache.spark.sql.types.{DataType, StructType}
 
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/LocalRelation.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/LocalRelation.scala
index f9f1f88cec..5813b74c77 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/LocalRelation.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/LocalRelation.scala
@@ -19,7 +19,7 @@ package org.apache.spark.sql.catalyst.plans.logical
 
 import org.apache.spark.sql.Row
 import org.apache.spark.sql.catalyst.{analysis, CatalystTypeConverters, InternalRow}
-import org.apache.spark.sql.catalyst.expressions.{Attribute, AttributeSet}
+import org.apache.spark.sql.catalyst.expressions.Attribute
 import org.apache.spark.sql.types.{StructField, StructType}
 
 object LocalRelation {
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/physical/partitioning.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/physical/partitioning.scala
index 45e2841ec9..be9f1ffa22 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/physical/partitioning.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/physical/partitioning.scala
@@ -17,7 +17,6 @@
 
 package org.apache.spark.sql.catalyst.plans.physical
 
-import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.types.{DataType, IntegerType}
 
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala
index e46ce1cee7..2d0bf6b375 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala
@@ -28,15 +28,12 @@ import org.json4s.jackson.JsonMethods._
 
 import org.apache.spark.SparkContext
 import org.apache.spark.rdd.{EmptyRDD, RDD}
-import org.apache.spark.sql.catalyst.{ScalaReflectionLock, TableIdentifier}
 import org.apache.spark.sql.catalyst.ScalaReflection._
+import org.apache.spark.sql.catalyst.ScalaReflectionLock
 import org.apache.spark.sql.catalyst.errors._
 import org.apache.spark.sql.catalyst.expressions._
-import org.apache.spark.sql.catalyst.plans.logical.Statistics
-import org.apache.spark.sql.catalyst.util.DateTimeUtils
 import org.apache.spark.sql.types._
 import org.apache.spark.storage.StorageLevel
-import org.apache.spark.unsafe.types.{CalendarInterval, UTF8String}
 import org.apache.spark.util.Utils
 
 /** Used by [[TreeNode.getNodeNumbered]] when traversing the tree for a given number */
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/ScalaReflectionSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/ScalaReflectionSuite.scala
index a32f5b70a0..5fe09b1a4d 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/ScalaReflectionSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/ScalaReflectionSuite.scala
@@ -17,7 +17,6 @@
 
 package org.apache.spark.sql.catalyst
 
-import java.math.BigInteger
 import java.sql.{Date, Timestamp}
 
 import org.apache.spark.SparkFunSuite
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/encoders/RowEncoderSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/encoders/RowEncoderSuite.scala
index 932511134c..f119c6f4f7 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/encoders/RowEncoderSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/encoders/RowEncoderSuite.scala
@@ -23,7 +23,6 @@ import org.apache.spark.SparkFunSuite
 import org.apache.spark.sql.{RandomDataGenerator, Row}
 import org.apache.spark.sql.catalyst.util.{ArrayData, GenericArrayData}
 import org.apache.spark.sql.types._
-import org.apache.spark.unsafe.types.UTF8String
 
 @SQLUserDefinedType(udt = classOf[ExamplePointUDT])
 class ExamplePoint(val x: Double, val y: Double) extends Serializable {
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/LiteralGenerator.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/LiteralGenerator.scala
index d9c91415e2..032aec0178 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/LiteralGenerator.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/LiteralGenerator.scala
@@ -20,8 +20,6 @@ package org.apache.spark.sql.catalyst.expressions
 import java.sql.{Date, Timestamp}
 
 import org.scalacheck.{Arbitrary, Gen}
-import org.scalatest.Matchers
-import org.scalatest.prop.GeneratorDrivenPropertyChecks
 
 import org.apache.spark.sql.types._
 import org.apache.spark.unsafe.types.CalendarInterval
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/aggregate/HyperLogLogPlusPlusSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/aggregate/HyperLogLogPlusPlusSuite.scala
index 83838294a9..0dbfb01e88 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/aggregate/HyperLogLogPlusPlusSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/aggregate/HyperLogLogPlusPlusSuite.scala
@@ -21,8 +21,6 @@ import java.util.Random
 
 import scala.collection.mutable
 
-import org.scalatest.Assertions._
-
 import org.apache.spark.SparkFunSuite
 import org.apache.spark.sql.catalyst.expressions.{BoundReference, MutableRow, SpecificMutableRow}
 import org.apache.spark.sql.types.{DataType, IntegerType}
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/AggregateOptimizeSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/AggregateOptimizeSuite.scala
index a4a12c0d62..e458eb8a1d 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/AggregateOptimizeSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/AggregateOptimizeSuite.scala
@@ -21,7 +21,7 @@ import org.apache.spark.sql.catalyst.dsl.expressions._
 import org.apache.spark.sql.catalyst.dsl.plans._
 import org.apache.spark.sql.catalyst.expressions.Literal
 import org.apache.spark.sql.catalyst.plans.PlanTest
-import org.apache.spark.sql.catalyst.plans.logical.{Aggregate, Distinct, LocalRelation, LogicalPlan}
+import org.apache.spark.sql.catalyst.plans.logical.{LocalRelation, LogicalPlan}
 import org.apache.spark.sql.catalyst.rules.RuleExecutor
 
 class AggregateOptimizeSuite extends PlanTest {
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/OptimizeInSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/OptimizeInSuite.scala
index 17255ecfe8..0e43ce034f 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/OptimizeInSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/OptimizeInSuite.scala
@@ -17,8 +17,6 @@
 
 package org.apache.spark.sql.catalyst.optimizer
 
-import scala.collection.immutable.HashSet
-
 import org.apache.spark.sql.catalyst.analysis.{EliminateSubqueryAliases, UnresolvedAttribute}
 import org.apache.spark.sql.catalyst.dsl.expressions._
 import org.apache.spark.sql.catalyst.dsl.plans._
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/plans/LogicalPlanSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/plans/LogicalPlanSuite.scala
index 455a3810c7..faef9ed274 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/plans/LogicalPlanSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/plans/LogicalPlanSuite.scala
@@ -18,9 +18,7 @@
 package org.apache.spark.sql.catalyst.plans
 
 import org.apache.spark.SparkFunSuite
-import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.catalyst.plans.logical._
-import org.apache.spark.sql.catalyst.util._
 
 /**
  * This suite is used to test [[LogicalPlan]]'s `resolveOperators` and make sure it can correctly
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/plans/SameResultSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/plans/SameResultSuite.scala
index fb4f34d059..37941cf34e 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/plans/SameResultSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/plans/SameResultSuite.scala
@@ -20,7 +20,6 @@ package org.apache.spark.sql.catalyst.plans
 import org.apache.spark.SparkFunSuite
 import org.apache.spark.sql.catalyst.dsl.expressions._
 import org.apache.spark.sql.catalyst.dsl.plans._
-import org.apache.spark.sql.catalyst.expressions.{AttributeReference, ExprId}
 import org.apache.spark.sql.catalyst.plans.logical.{LocalRelation, LogicalPlan}
 import org.apache.spark.sql.catalyst.util._
 
diff --git a/sql/core/src/main/java/org/apache/spark/sql/execution/UnsafeFixedWidthAggregationMap.java b/sql/core/src/main/java/org/apache/spark/sql/execution/UnsafeFixedWidthAggregationMap.java
index 2e84178d69..57e8218f3b 100644
--- a/sql/core/src/main/java/org/apache/spark/sql/execution/UnsafeFixedWidthAggregationMap.java
+++ b/sql/core/src/main/java/org/apache/spark/sql/execution/UnsafeFixedWidthAggregationMap.java
@@ -29,7 +29,6 @@ import org.apache.spark.sql.types.StructType;
 import org.apache.spark.unsafe.KVIterator;
 import org.apache.spark.unsafe.Platform;
 import org.apache.spark.unsafe.map.BytesToBytesMap;
-import org.apache.spark.unsafe.memory.MemoryLocation;
 
 /**
  * Unsafe-based HashMap for performing aggregations where the aggregated values are fixed-width.
diff --git a/sql/core/src/main/java/org/apache/spark/sql/execution/datasources/parquet/VectorizedPlainValuesReader.java b/sql/core/src/main/java/org/apache/spark/sql/execution/datasources/parquet/VectorizedPlainValuesReader.java
index ee9a7a221b..2672e0453b 100644
--- a/sql/core/src/main/java/org/apache/spark/sql/execution/datasources/parquet/VectorizedPlainValuesReader.java
+++ b/sql/core/src/main/java/org/apache/spark/sql/execution/datasources/parquet/VectorizedPlainValuesReader.java
@@ -18,11 +18,9 @@ package org.apache.spark.sql.execution.datasources.parquet;
 
 import java.io.IOException;
 
-import org.apache.spark.sql.Column;
 import org.apache.spark.sql.execution.vectorized.ColumnVector;
 import org.apache.spark.unsafe.Platform;
 
-import org.apache.commons.lang.NotImplementedException;
 import org.apache.parquet.column.values.ValuesReader;
 import org.apache.parquet.io.api.Binary;
 
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala b/sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala
index 5f5b7f4c19..844bc0fdd1 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala
@@ -20,7 +20,6 @@ package org.apache.spark.sql
 import java.io.CharArrayWriter
 
 import scala.language.implicitConversions
-import scala.reflect.ClassTag
 import scala.reflect.runtime.universe.TypeTag
 
 import com.fasterxml.jackson.core.JsonFactory
@@ -37,7 +36,8 @@ import org.apache.spark.sql.catalyst.optimizer.CombineUnions
 import org.apache.spark.sql.catalyst.plans._
 import org.apache.spark.sql.catalyst.plans.logical._
 import org.apache.spark.sql.catalyst.util.usePrettyExpression
-import org.apache.spark.sql.execution.{ExplainCommand, FileRelation, LogicalRDD, Queryable, QueryExecution, SQLExecution}
+import org.apache.spark.sql.execution.{ExplainCommand, FileRelation, LogicalRDD, Queryable,
+  QueryExecution, SQLExecution}
 import org.apache.spark.sql.execution.datasources.{CreateTableUsingAsSelect, LogicalRelation}
 import org.apache.spark.sql.execution.datasources.json.JacksonGenerator
 import org.apache.spark.sql.execution.python.EvaluatePython
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/GroupedDataset.scala b/sql/core/src/main/scala/org/apache/spark/sql/GroupedDataset.scala
index 53cb8eb524..cd8ed472ec 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/GroupedDataset.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/GroupedDataset.scala
@@ -25,7 +25,6 @@ import org.apache.spark.sql.catalyst.encoders.{encoderFor, ExpressionEncoder, Ou
 import org.apache.spark.sql.catalyst.expressions.{Alias, Attribute, CreateStruct}
 import org.apache.spark.sql.catalyst.plans.logical._
 import org.apache.spark.sql.execution.QueryExecution
-import org.apache.spark.sql.expressions.Aggregator
 
 /**
  * :: Experimental ::
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/api/r/SQLUtils.scala b/sql/core/src/main/scala/org/apache/spark/sql/api/r/SQLUtils.scala
index d8af799d89..22ded7a4bf 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/api/r/SQLUtils.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/api/r/SQLUtils.scala
@@ -24,8 +24,8 @@ import scala.util.matching.Regex
 import org.apache.spark.api.java.{JavaRDD, JavaSparkContext}
 import org.apache.spark.api.r.SerDe
 import org.apache.spark.rdd.RDD
-import org.apache.spark.sql.{Column, DataFrame, GroupedData, Row, SaveMode, SQLContext}
-import org.apache.spark.sql.catalyst.expressions.{Alias, Expression, GenericRowWithSchema, NamedExpression}
+import org.apache.spark.sql.{DataFrame, Row, SaveMode, SQLContext}
+import org.apache.spark.sql.catalyst.expressions.GenericRowWithSchema
 import org.apache.spark.sql.types._
 
 private[r] object SQLUtils {
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/SparkQl.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/SparkQl.scala
index 4174e27e9c..8c41d80bf1 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/SparkQl.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/SparkQl.scala
@@ -21,7 +21,6 @@ import org.apache.spark.sql.catalyst.{CatalystQl, TableIdentifier}
 import org.apache.spark.sql.catalyst.analysis.UnresolvedRelation
 import org.apache.spark.sql.catalyst.parser.{ASTNode, ParserConf, SimpleParserConf}
 import org.apache.spark.sql.catalyst.plans.logical.{LogicalPlan, OneRowRelation}
-import org.apache.spark.sql.catalyst.plans.logical
 import org.apache.spark.sql.execution.datasources._
 import org.apache.spark.sql.types.StructType
 
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/aggregate/TungstenAggregationIterator.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/aggregate/TungstenAggregationIterator.scala
index c4f6594835..5e1ea90cd4 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/aggregate/TungstenAggregationIterator.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/aggregate/TungstenAggregationIterator.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.sql.execution.aggregate
 
-import org.apache.spark.{InternalAccumulator, Logging, TaskContext}
+import org.apache.spark.{Logging, TaskContext}
 import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.catalyst.expressions.aggregate._
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/WriterContainer.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/WriterContainer.scala
index 097e9c912b..3653aca994 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/WriterContainer.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/WriterContainer.scala
@@ -26,7 +26,6 @@ import org.apache.hadoop.mapreduce.task.TaskAttemptContextImpl
 
 import org.apache.spark._
 import org.apache.spark.mapred.SparkHadoopMapRedUtil
-import org.apache.spark.sql._
 import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.catalyst.plans.physical.HashPartitioning
 import org.apache.spark.sql.catalyst.InternalRow
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/json/JSONRelation.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/json/JSONRelation.scala
index 28136911fe..2eba52f326 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/json/JSONRelation.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/json/JSONRelation.scala
@@ -23,7 +23,6 @@ import com.fasterxml.jackson.core.JsonFactory
 import com.google.common.base.Objects
 import org.apache.hadoop.fs.{FileStatus, Path}
 import org.apache.hadoop.io.{LongWritable, NullWritable, Text}
-import org.apache.hadoop.io.SequenceFile.CompressionType
 import org.apache.hadoop.mapred.{JobConf, TextInputFormat}
 import org.apache.hadoop.mapreduce.{Job, RecordWriter, TaskAttemptContext}
 import org.apache.hadoop.mapreduce.lib.input.FileInputFormat
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/json/JacksonGenerator.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/json/JacksonGenerator.scala
index 078e1cbec5..8b920ecafa 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/json/JacksonGenerator.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/json/JacksonGenerator.scala
@@ -17,11 +17,8 @@
 
 package org.apache.spark.sql.execution.datasources.json
 
-import scala.collection.Map
-
 import com.fasterxml.jackson.core._
 
-import org.apache.spark.sql.Row
 import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.catalyst.util.{ArrayData, DateTimeUtils, MapData}
 import org.apache.spark.sql.types._
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/parquet/CatalystReadSupport.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/parquet/CatalystReadSupport.scala
index c3b7483e80..e34309bab1 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/parquet/CatalystReadSupport.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/parquet/CatalystReadSupport.scala
@@ -29,7 +29,6 @@ import org.apache.parquet.schema._
 import org.apache.parquet.schema.Type.Repetition
 
 import org.apache.spark.Logging
-import org.apache.spark.deploy.SparkHadoopUtil
 import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.types._
 
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/joins/HashSemiJoin.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/joins/HashSemiJoin.scala
index 3eed6e3e11..813ec02425 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/joins/HashSemiJoin.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/joins/HashSemiJoin.scala
@@ -19,7 +19,6 @@ package org.apache.spark.sql.execution.joins
 
 import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.catalyst.expressions._
-import org.apache.spark.sql.catalyst.plans.physical.BroadcastMode
 import org.apache.spark.sql.execution.SparkPlan
 import org.apache.spark.sql.execution.metric.LongSQLMetric
 
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/joins/HashedRelation.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/joins/HashedRelation.scala
index 606269bf25..9a3cdaf697 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/joins/HashedRelation.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/joins/HashedRelation.scala
@@ -26,7 +26,7 @@ import org.apache.spark.memory.{StaticMemoryManager, TaskMemoryManager}
 import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.catalyst.plans.physical.BroadcastMode
-import org.apache.spark.sql.execution.{SparkPlan, SparkSqlSerializer}
+import org.apache.spark.sql.execution.SparkSqlSerializer
 import org.apache.spark.sql.execution.local.LocalNode
 import org.apache.spark.unsafe.Platform
 import org.apache.spark.unsafe.map.BytesToBytesMap
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/limit.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/limit.scala
index 45175d36d5..5a7516b7f9 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/limit.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/limit.scala
@@ -24,7 +24,6 @@ import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.catalyst.expressions.codegen.{CodegenContext, ExprCode, LazilyGeneratedOrdering}
 import org.apache.spark.sql.catalyst.plans.physical._
 import org.apache.spark.sql.execution.exchange.ShuffleExchange
-import org.apache.spark.sql.execution.metric.SQLMetrics
 
 
 /**
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/local/BinaryHashJoinNode.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/local/BinaryHashJoinNode.scala
index 8f063e24fb..97f9358016 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/local/BinaryHashJoinNode.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/local/BinaryHashJoinNode.scala
@@ -17,7 +17,6 @@
 
 package org.apache.spark.sql.execution.local
 
-import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.execution.joins.{BuildLeft, BuildRight, BuildSide, HashedRelation}
 import org.apache.spark.sql.internal.SQLConf
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/local/BroadcastHashJoinNode.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/local/BroadcastHashJoinNode.scala
index 9ffa272d21..779f4833fa 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/local/BroadcastHashJoinNode.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/local/BroadcastHashJoinNode.scala
@@ -18,7 +18,6 @@
 package org.apache.spark.sql.execution.local
 
 import org.apache.spark.broadcast.Broadcast
-import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.execution.joins.{BuildLeft, BuildRight, BuildSide, HashedRelation}
 import org.apache.spark.sql.internal.SQLConf
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/streaming/CompositeOffset.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/streaming/CompositeOffset.scala
index d2cb20ef8b..59a52a3d59 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/streaming/CompositeOffset.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/streaming/CompositeOffset.scala
@@ -17,8 +17,6 @@
 
 package org.apache.spark.sql.execution.streaming
 
-import scala.util.Try
-
 /**
  * An ordered collection of offsets, used to track the progress of processing data from one or more
  * [[Source]]s that are present in a streaming query. This is similar to simplified, single-instance
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/expressions/WindowSpec.scala b/sql/core/src/main/scala/org/apache/spark/sql/expressions/WindowSpec.scala
index 3921147857..9e9c58cb66 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/expressions/WindowSpec.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/expressions/WindowSpec.scala
@@ -20,7 +20,6 @@ package org.apache.spark.sql.expressions
 import org.apache.spark.annotation.Experimental
 import org.apache.spark.sql.{catalyst, Column}
 import org.apache.spark.sql.catalyst.expressions._
-import org.apache.spark.sql.catalyst.expressions.aggregate._
 
 /**
  * :: Experimental ::
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/UserDefinedTypeSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/UserDefinedTypeSuite.scala
index 6800a8ddf6..9081bc722a 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/UserDefinedTypeSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/UserDefinedTypeSuite.scala
@@ -26,7 +26,6 @@ import org.apache.spark.sql.execution.datasources.parquet.ParquetTest
 import org.apache.spark.sql.functions._
 import org.apache.spark.sql.test.SharedSQLContext
 import org.apache.spark.sql.types._
-import org.apache.spark.util.collection.OpenHashSet
 
 @SQLUserDefinedType(udt = classOf[MyDenseVectorUDT])
 private[sql] class MyDenseVector(val data: Array[Double]) extends Serializable {
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/ReferenceSort.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/ReferenceSort.scala
index 273937fa8c..2963a856d1 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/ReferenceSort.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/ReferenceSort.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.sql.execution
 
-import org.apache.spark.{InternalAccumulator, TaskContext}
+import org.apache.spark.TaskContext
 import org.apache.spark.rdd.RDD
 import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.catalyst.errors._
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/SQLExecutionSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/SQLExecutionSuite.scala
index 63639681ef..824d89e3b2 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/SQLExecutionSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/SQLExecutionSuite.scala
@@ -19,8 +19,6 @@ package org.apache.spark.sql.execution
 
 import java.util.Properties
 
-import scala.collection.parallel.CompositeThrowable
-
 import org.apache.spark.{SparkConf, SparkContext, SparkFunSuite}
 import org.apache.spark.sql.SQLContext
 
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/SparkPlanTest.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/SparkPlanTest.scala
index 8549a6a0f6..aa928cfc80 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/SparkPlanTest.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/SparkPlanTest.scala
@@ -18,11 +18,10 @@
 package org.apache.spark.sql.execution
 
 import scala.language.implicitConversions
-import scala.reflect.runtime.universe.TypeTag
 import scala.util.control.NonFatal
 
 import org.apache.spark.SparkFunSuite
-import org.apache.spark.sql.{DataFrame, DataFrameHolder, Row, SQLContext}
+import org.apache.spark.sql.{DataFrame, Row, SQLContext}
 import org.apache.spark.sql.catalyst.analysis.UnresolvedAttribute
 import org.apache.spark.sql.test.SQLTestUtils
 
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/UnsafeFixedWidthAggregationMapSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/UnsafeFixedWidthAggregationMapSuite.scala
index c7df8b51e2..4dc7d3461c 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/UnsafeFixedWidthAggregationMapSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/UnsafeFixedWidthAggregationMapSuite.scala
@@ -26,7 +26,7 @@ import org.scalatest.Matchers
 import org.apache.spark.{SparkConf, SparkFunSuite, TaskContext, TaskContextImpl}
 import org.apache.spark.memory.{TaskMemoryManager, TestMemoryManager}
 import org.apache.spark.sql.catalyst.InternalRow
-import org.apache.spark.sql.catalyst.expressions.{UnsafeProjection, UnsafeRow}
+import org.apache.spark.sql.catalyst.expressions.UnsafeRow
 import org.apache.spark.sql.test.SharedSQLContext
 import org.apache.spark.sql.types._
 import org.apache.spark.unsafe.types.UTF8String
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/UnsafeRowSerializerSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/UnsafeRowSerializerSuite.scala
index 7438e11ef7..50bdcd6c2c 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/UnsafeRowSerializerSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/UnsafeRowSerializerSuite.scala
@@ -20,7 +20,6 @@ package org.apache.spark.sql.execution
 import java.io.{ByteArrayInputStream, ByteArrayOutputStream, File}
 
 import org.apache.spark._
-import org.apache.spark.executor.ShuffleWriteMetrics
 import org.apache.spark.memory.TaskMemoryManager
 import org.apache.spark.rdd.RDD
 import org.apache.spark.sql.Row
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/columnar/PartitionBatchPruningSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/columnar/PartitionBatchPruningSuite.scala
index d19fec6140..4f185ed283 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/columnar/PartitionBatchPruningSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/columnar/PartitionBatchPruningSuite.scala
@@ -20,7 +20,6 @@ package org.apache.spark.sql.execution.columnar
 import org.scalatest.BeforeAndAfterEach
 
 import org.apache.spark.SparkFunSuite
-import org.apache.spark.sql._
 import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.sql.test.SharedSQLContext
 import org.apache.spark.sql.test.SQLTestData._
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/parquet/ParquetEncodingSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/parquet/ParquetEncodingSuite.scala
index 281a2cffa8..29318d8b56 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/parquet/ParquetEncodingSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/parquet/ParquetEncodingSuite.scala
@@ -16,7 +16,6 @@
  */
 package org.apache.spark.sql.execution.datasources.parquet
 
-import org.apache.spark.sql.execution.vectorized.ColumnVectorUtils
 import org.apache.spark.sql.test.SharedSQLContext
 
 // TODO: this needs a lot more testing but it's currently not easy to test with the parquet
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/local/HashJoinNodeSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/local/HashJoinNodeSuite.scala
index 268f2aac87..74142ea598 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/local/HashJoinNodeSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/local/HashJoinNodeSuite.scala
@@ -21,7 +21,7 @@ import org.mockito.Mockito.{mock, when}
 
 import org.apache.spark.broadcast.TorrentBroadcast
 import org.apache.spark.sql.catalyst.dsl.expressions._
-import org.apache.spark.sql.catalyst.expressions.{Expression, InterpretedMutableProjection, UnsafeProjection}
+import org.apache.spark.sql.catalyst.expressions.{Expression, UnsafeProjection}
 import org.apache.spark.sql.execution.joins.{BuildLeft, BuildRight, BuildSide, HashedRelation}
 import org.apache.spark.sql.internal.SQLConf
 
diff --git a/sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/SparkSQLCLIDriver.scala b/sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/SparkSQLCLIDriver.scala
index fb31119a9e..79cf7e8378 100644
--- a/sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/SparkSQLCLIDriver.scala
+++ b/sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/SparkSQLCLIDriver.scala
@@ -32,14 +32,15 @@ import org.apache.hadoop.hive.common.{HiveInterruptCallback, HiveInterruptUtils}
 import org.apache.hadoop.hive.conf.HiveConf
 import org.apache.hadoop.hive.ql.Driver
 import org.apache.hadoop.hive.ql.exec.Utilities
-import org.apache.hadoop.hive.ql.processors.{AddResourceProcessor, CommandProcessor, CommandProcessorFactory, SetProcessor}
+import org.apache.hadoop.hive.ql.processors.{AddResourceProcessor, CommandProcessor,
+  CommandProcessorFactory, SetProcessor}
 import org.apache.hadoop.hive.ql.session.SessionState
 import org.apache.thrift.transport.TSocket
 
 import org.apache.spark.Logging
 import org.apache.spark.sql.AnalysisException
 import org.apache.spark.sql.hive.HiveContext
-import org.apache.spark.util.{ShutdownHookManager, Utils}
+import org.apache.spark.util.ShutdownHookManager
 
 /**
  * This code doesn't support remote connections in Hive 1.2+, as the underlying CliDriver
diff --git a/sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/SparkSQLDriver.scala b/sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/SparkSQLDriver.scala
index 4278aa30fb..0eb2627e7a 100644
--- a/sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/SparkSQLDriver.scala
+++ b/sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/SparkSQLDriver.scala
@@ -25,7 +25,6 @@ import org.apache.commons.lang3.exception.ExceptionUtils
 import org.apache.hadoop.hive.metastore.api.{FieldSchema, Schema}
 import org.apache.hadoop.hive.ql.Driver
 import org.apache.hadoop.hive.ql.processors.CommandProcessorResponse
-import org.apache.log4j.LogManager
 
 import org.apache.spark.Logging
 import org.apache.spark.sql.AnalysisException
diff --git a/sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/ui/ThriftServerTab.scala b/sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/ui/ThriftServerTab.scala
index 1dc7d79436..63e6bbcfee 100644
--- a/sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/ui/ThriftServerTab.scala
+++ b/sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/ui/ThriftServerTab.scala
@@ -18,7 +18,7 @@
 package org.apache.spark.sql.hive.thriftserver.ui
 
 import org.apache.spark.{Logging, SparkContext, SparkException}
-import org.apache.spark.sql.hive.thriftserver.{HiveThriftServer2, SparkSQLEnv}
+import org.apache.spark.sql.hive.thriftserver.HiveThriftServer2
 import org.apache.spark.sql.hive.thriftserver.ui.ThriftServerTab._
 import org.apache.spark.ui.{SparkUI, SparkUITab}
 
diff --git a/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveSessionState.scala b/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveSessionState.scala
index 09f54be04d..0d4b79f531 100644
--- a/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveSessionState.scala
+++ b/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveSessionState.scala
@@ -20,7 +20,6 @@ package org.apache.spark.sql.hive
 import org.apache.spark.sql._
 import org.apache.spark.sql.catalyst.ParserInterface
 import org.apache.spark.sql.catalyst.analysis.{Analyzer, FunctionRegistry, OverrideCatalog}
-import org.apache.spark.sql.catalyst.expressions.Expression
 import org.apache.spark.sql.execution.{python, SparkPlanner}
 import org.apache.spark.sql.execution.datasources._
 import org.apache.spark.sql.internal.{SessionState, SQLConf}
diff --git a/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveStrategies.scala b/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveStrategies.scala
index 3687dd6f5a..8883e370dc 100644
--- a/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveStrategies.scala
+++ b/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveStrategies.scala
@@ -23,7 +23,8 @@ import org.apache.spark.sql.catalyst.planning._
 import org.apache.spark.sql.catalyst.plans._
 import org.apache.spark.sql.catalyst.plans.logical.LogicalPlan
 import org.apache.spark.sql.execution.{DescribeCommand => RunnableDescribeCommand, _}
-import org.apache.spark.sql.execution.datasources.{CreateTableUsing, CreateTableUsingAsSelect, DescribeCommand}
+import org.apache.spark.sql.execution.datasources.{CreateTableUsing, CreateTableUsingAsSelect,
+  DescribeCommand}
 import org.apache.spark.sql.hive.execution._
 
 private[hive] trait HiveStrategies {
diff --git a/sql/hive/src/main/scala/org/apache/spark/sql/hive/SQLBuilder.scala b/sql/hive/src/main/scala/org/apache/spark/sql/hive/SQLBuilder.scala
index bc48ed4f08..13a78c609e 100644
--- a/sql/hive/src/main/scala/org/apache/spark/sql/hive/SQLBuilder.scala
+++ b/sql/hive/src/main/scala/org/apache/spark/sql/hive/SQLBuilder.scala
@@ -24,7 +24,8 @@ import scala.util.control.NonFatal
 import org.apache.spark.Logging
 import org.apache.spark.sql.{DataFrame, SQLContext}
 import org.apache.spark.sql.catalyst.TableIdentifier
-import org.apache.spark.sql.catalyst.expressions.{Attribute, NamedExpression, NonSQLExpression, SortOrder}
+import org.apache.spark.sql.catalyst.expressions.{Attribute, NamedExpression, NonSQLExpression,
+  SortOrder}
 import org.apache.spark.sql.catalyst.optimizer.CollapseProject
 import org.apache.spark.sql.catalyst.plans.logical._
 import org.apache.spark.sql.catalyst.rules.{Rule, RuleExecutor}
diff --git a/sql/hive/src/main/scala/org/apache/spark/sql/hive/TableReader.scala b/sql/hive/src/main/scala/org/apache/spark/sql/hive/TableReader.scala
index fd465e80a8..5754bbb82d 100644
--- a/sql/hive/src/main/scala/org/apache/spark/sql/hive/TableReader.scala
+++ b/sql/hive/src/main/scala/org/apache/spark/sql/hive/TableReader.scala
@@ -23,10 +23,12 @@ import org.apache.hadoop.fs.{Path, PathFilter}
 import org.apache.hadoop.hive.conf.HiveConf
 import org.apache.hadoop.hive.metastore.api.hive_metastoreConstants._
 import org.apache.hadoop.hive.ql.exec.Utilities
-import org.apache.hadoop.hive.ql.metadata.{Hive, HiveStorageHandler, HiveUtils, Partition => HivePartition, Table => HiveTable}
+import org.apache.hadoop.hive.ql.metadata.{HiveUtils, Partition => HivePartition,
+  Table => HiveTable}
 import org.apache.hadoop.hive.ql.plan.TableDesc
 import org.apache.hadoop.hive.serde2.Deserializer
-import org.apache.hadoop.hive.serde2.objectinspector.{ObjectInspectorConverters, StructObjectInspector}
+import org.apache.hadoop.hive.serde2.objectinspector.{ObjectInspectorConverters,
+  StructObjectInspector}
 import org.apache.hadoop.hive.serde2.objectinspector.primitive._
 import org.apache.hadoop.io.Writable
 import org.apache.hadoop.mapred.{FileInputFormat, InputFormat, JobConf}
diff --git a/sql/hive/src/main/scala/org/apache/spark/sql/hive/execution/InsertIntoHiveTable.scala b/sql/hive/src/main/scala/org/apache/spark/sql/hive/execution/InsertIntoHiveTable.scala
index a89ed48608..b3d38dfdb4 100644
--- a/sql/hive/src/main/scala/org/apache/spark/sql/hive/execution/InsertIntoHiveTable.scala
+++ b/sql/hive/src/main/scala/org/apache/spark/sql/hive/execution/InsertIntoHiveTable.scala
@@ -33,7 +33,6 @@ import org.apache.spark.sql.execution.{SparkPlan, UnaryNode}
 import org.apache.spark.sql.hive._
 import org.apache.spark.sql.hive.HiveShim.{ShimFileSinkDesc => FileSinkDesc}
 import org.apache.spark.SparkException
-import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.util.SerializableJobConf
 
 private[hive]
diff --git a/sql/hive/src/main/scala/org/apache/spark/sql/hive/hiveUDFs.scala b/sql/hive/src/main/scala/org/apache/spark/sql/hive/hiveUDFs.scala
index bcafa045e0..abcc565683 100644
--- a/sql/hive/src/main/scala/org/apache/spark/sql/hive/hiveUDFs.scala
+++ b/sql/hive/src/main/scala/org/apache/spark/sql/hive/hiveUDFs.scala
@@ -26,7 +26,8 @@ import org.apache.hadoop.hive.ql.udf.{UDFType => HiveUDFType}
 import org.apache.hadoop.hive.ql.udf.generic._
 import org.apache.hadoop.hive.ql.udf.generic.GenericUDF._
 import org.apache.hadoop.hive.ql.udf.generic.GenericUDFUtils.ConversionHelper
-import org.apache.hadoop.hive.serde2.objectinspector.{ConstantObjectInspector, ObjectInspector, ObjectInspectorFactory}
+import org.apache.hadoop.hive.serde2.objectinspector.{ConstantObjectInspector, ObjectInspector,
+  ObjectInspectorFactory}
 import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorFactory.ObjectInspectorOptions
 
 import org.apache.spark.Logging
diff --git a/sql/hive/src/test/scala/org/apache/spark/sql/hive/CachedTableSuite.scala b/sql/hive/src/test/scala/org/apache/spark/sql/hive/CachedTableSuite.scala
index 86f02e68e5..656c1317c1 100644
--- a/sql/hive/src/test/scala/org/apache/spark/sql/hive/CachedTableSuite.scala
+++ b/sql/hive/src/test/scala/org/apache/spark/sql/hive/CachedTableSuite.scala
@@ -21,7 +21,6 @@ import java.io.File
 
 import org.apache.spark.sql.{AnalysisException, QueryTest, SaveMode}
 import org.apache.spark.sql.execution.columnar.InMemoryColumnarTableScan
-import org.apache.spark.sql.execution.datasources.parquet.ParquetRelation
 import org.apache.spark.sql.hive.test.TestHiveSingleton
 import org.apache.spark.storage.RDDBlockId
 import org.apache.spark.util.Utils
diff --git a/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveOperatorQueryableSuite.scala b/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveOperatorQueryableSuite.scala
index 9bdc24162b..b252c6ee2f 100644
--- a/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveOperatorQueryableSuite.scala
+++ b/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveOperatorQueryableSuite.scala
@@ -18,7 +18,7 @@
 package org.apache.spark.sql.hive.execution
 
 import org.apache.spark.sql.{QueryTest, Row}
-import org.apache.spark.sql.hive.test.{TestHive, TestHiveSingleton}
+import org.apache.spark.sql.hive.test.TestHiveSingleton
 
 /**
  * A set of tests that validates commands can also be queried by like a table