Reenable Checkstyle's unused import rule (#31270)

buildSrc/src/main/resources/checkstyle.xml

@@ -26,13 +26,9 @@
     </module>
 
     <module name="AvoidStarImport" />
-    <!-- Doesn't pass but we could make it pass pretty quick.
-    <module name="UnusedImports">
-      The next property is optional. If we remove it then imports that are
-      only referenced by Javadoc cause the check to fail.
-      <property name="processJavadoc" value="true" />
-    </module>
-    -->
+
+    <!-- Unused imports are forbidden -->
+    <module name="UnusedImports" />
 
     <!-- Non-inner classes must be in files that match their names. -->
     <module name="OuterTypeFilename" />

client/rest-high-level/src/test/java/org/elasticsearch/client/documentation/MigrationDocumentationIT.java

@@ -30,10 +30,6 @@
 import org.elasticsearch.client.RequestOptions;
 import org.elasticsearch.client.Response;
 import org.elasticsearch.client.RestHighLevelClient;
-import org.apache.http.HttpEntity;
-import org.apache.http.HttpStatus;
-import org.apache.http.entity.ContentType;
-import org.apache.http.nio.entity.NStringEntity;
 import org.elasticsearch.cluster.health.ClusterHealthStatus;
 import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.common.xcontent.XContentType;

modules/analysis-common/src/test/java/org/elasticsearch/analysis/common/SynonymsAnalysisTests.java

@@ -22,10 +22,8 @@
 import org.apache.lucene.analysis.Analyzer;
 import org.apache.lucene.analysis.TokenStream;
 import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
-import org.apache.lucene.queryparser.classic.ParseException;
 import org.elasticsearch.Version;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
-import org.elasticsearch.common.logging.Loggers;
 import org.elasticsearch.common.lucene.all.AllTokenStream;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;

modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/ScriptProcessorFactoryTests.java

@@ -20,7 +20,6 @@
 package org.elasticsearch.ingest.common;
 
 import org.elasticsearch.ElasticsearchException;
-import org.elasticsearch.common.xcontent.XContentParseException;
 import org.elasticsearch.script.Script;
 import org.elasticsearch.script.ScriptException;
 import org.elasticsearch.script.ScriptService;

modules/mapper-extras/src/test/java/org/elasticsearch/index/mapper/RangeFieldQueryStringQueryBuilderTests.java

@@ -21,20 +21,17 @@
 
 import org.apache.lucene.document.DoubleRange;
 import org.apache.lucene.document.FloatRange;
-import org.apache.lucene.document.InetAddressPoint;
 import org.apache.lucene.document.InetAddressRange;
 import org.apache.lucene.document.IntRange;
 import org.apache.lucene.document.LongRange;
 import org.apache.lucene.queries.BinaryDocValuesRangeQuery;
 import org.apache.lucene.search.IndexOrDocValuesQuery;
 import org.apache.lucene.search.PointRangeQuery;
 import org.apache.lucene.search.Query;
-import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.action.admin.indices.mapping.put.PutMappingRequest;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.compress.CompressedXContent;
 import org.elasticsearch.common.joda.DateMathParser;
-import org.elasticsearch.common.joda.Joda;
 import org.elasticsearch.common.network.InetAddresses;
 import org.elasticsearch.index.query.QueryShardContext;
 import org.elasticsearch.index.query.QueryStringQueryBuilder;

modules/parent-join/src/test/java/org/elasticsearch/join/query/LegacyHasChildQueryBuilderTests.java

@@ -33,7 +33,6 @@
 import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.Version;
 import org.elasticsearch.action.admin.indices.mapping.put.PutMappingRequest;
-import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.compress.CompressedXContent;
 import org.elasticsearch.common.settings.Settings;

modules/percolator/src/main/java/org/elasticsearch/percolator/QueryAnalyzer.java

@@ -55,7 +55,6 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
-import java.util.Comparator;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;

modules/reindex/src/test/java/org/elasticsearch/client/documentation/ReindexDocumentationIT.java

@@ -28,7 +28,6 @@
 import org.elasticsearch.index.reindex.BulkByScrollTask;
 import org.elasticsearch.index.reindex.DeleteByQueryAction;
 import org.elasticsearch.index.reindex.ReindexAction;
-import org.elasticsearch.index.reindex.ReindexRequestBuilder;
 import org.elasticsearch.index.reindex.RethrottleAction;
 import org.elasticsearch.index.reindex.UpdateByQueryAction;
 import org.elasticsearch.index.reindex.UpdateByQueryRequestBuilder;

modules/transport-netty4/src/main/java/org/elasticsearch/transport/netty4/Netty4Transport.java

@@ -56,7 +56,6 @@
 import org.elasticsearch.common.util.concurrent.EsExecutors;
 import org.elasticsearch.indices.breaker.CircuitBreakerService;
 import org.elasticsearch.threadpool.ThreadPool;
-import org.elasticsearch.transport.TcpChannel;
 import org.elasticsearch.transport.TcpTransport;
 import org.elasticsearch.transport.TransportRequestOptions;
 

modules/transport-netty4/src/main/java/org/elasticsearch/transport/netty4/NettyTcpChannel.java

@@ -20,19 +20,14 @@
 package org.elasticsearch.transport.netty4;
 
 import io.netty.channel.Channel;
-import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.ChannelPromise;
-import org.apache.logging.log4j.message.ParameterizedMessage;
-import org.apache.logging.log4j.util.Supplier;
-import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.transport.TcpChannel;
 import org.elasticsearch.transport.TransportException;
 
 import java.net.InetSocketAddress;
-import java.nio.channels.ClosedSelectorException;
 import java.util.concurrent.CompletableFuture;
 
 public class NettyTcpChannel implements TcpChannel {

modules/transport-netty4/src/test/java/org/elasticsearch/http/netty4/Netty4HttpServerPipeliningTests.java

@@ -32,7 +32,6 @@
 import io.netty.handler.codec.http.HttpHeaderNames;
 import io.netty.handler.codec.http.HttpResponseStatus;
 import io.netty.handler.codec.http.HttpVersion;
-import org.elasticsearch.common.network.NetworkModule;
 import org.elasticsearch.common.network.NetworkService;
 import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Settings;

plugins/discovery-file/src/main/java/org/elasticsearch/discovery/file/FileBasedUnicastHostsProvider.java

@@ -23,7 +23,6 @@
 import org.apache.logging.log4j.util.Supplier;
 import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.common.component.AbstractComponent;
-import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.discovery.zen.UnicastHostsProvider;
 import org.elasticsearch.env.Environment;

plugins/discovery-gce/src/main/java/org/elasticsearch/plugin/discovery/gce/GceDiscoveryPlugin.java

@@ -29,7 +29,6 @@
 import org.elasticsearch.cloud.gce.GceMetadataService;
 import org.elasticsearch.cloud.gce.network.GceNameResolver;
 import org.elasticsearch.cloud.gce.util.Access;
-import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.logging.Loggers;
 import org.elasticsearch.common.network.NetworkService;
 import org.elasticsearch.common.settings.Setting;

plugins/repository-azure/src/main/java/org/elasticsearch/cloud/azure/blobstore/AzureBlobContainer.java

@@ -32,7 +32,6 @@
 import java.io.InputStream;
 import java.net.HttpURLConnection;
 import java.net.URISyntaxException;
-import java.nio.file.FileAlreadyExistsException;
 import java.nio.file.NoSuchFileException;
 import java.util.Map;
 

qa/query-builder-bwc/src/test/java/org/elasticsearch/bwc/QueryBuilderBWCIT.java

@@ -19,9 +19,6 @@
 
 package org.elasticsearch.bwc;
 
-import org.apache.http.entity.ContentType;
-import org.apache.http.entity.StringEntity;
-import org.apache.http.util.EntityUtils;
 import org.apache.http.util.EntityUtils;
 import org.elasticsearch.Version;
 import org.elasticsearch.client.Request;

server/src/main/java/org/elasticsearch/action/bulk/TransportShardBulkAction.java

@@ -29,7 +29,6 @@
 import org.elasticsearch.action.index.IndexRequest;
 import org.elasticsearch.action.index.IndexResponse;
 import org.elasticsearch.action.support.ActionFilters;
-import org.elasticsearch.action.support.TransportActions;
 import org.elasticsearch.action.support.replication.ReplicationOperation;
 import org.elasticsearch.action.support.replication.ReplicationResponse.ShardInfo;
 import org.elasticsearch.action.support.replication.TransportReplicationAction;

server/src/main/java/org/elasticsearch/action/get/TransportGetAction.java

@@ -25,7 +25,6 @@
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
-import org.elasticsearch.cluster.routing.Preference;
 import org.elasticsearch.cluster.routing.ShardIterator;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.inject.Inject;

server/src/main/java/org/elasticsearch/action/ingest/PutPipelineAction.java

@@ -20,7 +20,6 @@
 package org.elasticsearch.action.ingest;
 
 import org.elasticsearch.action.Action;
-import org.elasticsearch.action.index.IndexResponse;
 import org.elasticsearch.client.ElasticsearchClient;
 
 public class PutPipelineAction extends Action<PutPipelineRequest, WritePipelineResponse, PutPipelineRequestBuilder> {

server/src/main/java/org/elasticsearch/action/search/TransportMultiSearchAction.java

@@ -34,7 +34,6 @@
 import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.transport.TransportService;
 
-import java.util.List;
 import java.util.Queue;
 import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.atomic.AtomicInteger;

server/src/main/java/org/elasticsearch/cluster/ClusterName.java

@@ -22,7 +22,6 @@
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.io.stream.Writeable;
-import org.elasticsearch.common.logging.Loggers;
 import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Settings;
 

server/src/main/java/org/elasticsearch/cluster/metadata/MetaDataMappingService.java

@@ -21,7 +21,6 @@
 
 import com.carrotsearch.hppc.cursors.ObjectCursor;
 import org.apache.logging.log4j.message.ParameterizedMessage;
-import org.apache.logging.log4j.util.Supplier;
 import org.elasticsearch.core.internal.io.IOUtils;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.admin.indices.mapping.put.PutMappingClusterStateUpdateRequest;

server/src/main/java/org/elasticsearch/common/CheckedRunnable.java

@@ -19,8 +19,6 @@
 
 package org.elasticsearch.common;
 
-import java.lang.Runnable;
-
 /**
  * A {@link Runnable}-like interface which allows throwing checked exceptions.
  */

server/src/main/java/org/elasticsearch/common/geo/builders/ShapeBuilders.java

@@ -22,7 +22,6 @@
 import java.util.List;
 
 import org.locationtech.jts.geom.Coordinate;
-import org.elasticsearch.common.io.stream.NamedWriteableRegistry.Entry;
 
 /**
  * A collection of static methods for creating ShapeBuilders.

server/src/main/java/org/elasticsearch/common/lucene/search/function/FunctionScoreQuery.java

@@ -30,8 +30,6 @@
 import org.apache.lucene.search.ScorerSupplier;
 import org.apache.lucene.search.Weight;
 import org.apache.lucene.util.Bits;
-import org.apache.lucene.search.TopDocsCollector;
-import org.apache.lucene.search.TopScoreDocCollector;
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
@@ -376,9 +374,9 @@ public float score() throws IOException {
             double factor = computeScore(docId, subQueryScore);
             float finalScore = scoreCombiner.combine(subQueryScore, factor, maxBoost);
             if (finalScore == Float.NEGATIVE_INFINITY || Float.isNaN(finalScore)) {
-                /**
-                 * These scores are invalid for score based {@link TopDocsCollector}s.
-                 * See {@link TopScoreDocCollector} for details.
+                /*
+                  These scores are invalid for score based {@link org.apache.lucene.search.TopDocsCollector}s.
+                  See {@link org.apache.lucene.search.TopScoreDocCollector} for details.
                  */
                 throw new ElasticsearchException("function score query returned an invalid score: " + finalScore + " for doc: " + docId);
             }

server/src/main/java/org/elasticsearch/common/settings/IndexScopedSettings.java

@@ -36,7 +36,6 @@
 import org.elasticsearch.index.fielddata.IndexFieldDataService;
 import org.elasticsearch.index.mapper.FieldMapper;
 import org.elasticsearch.index.mapper.MapperService;
-import org.elasticsearch.index.seqno.LocalCheckpointTracker;
 import org.elasticsearch.index.similarity.SimilarityService;
 import org.elasticsearch.index.store.FsDirectoryService;
 import org.elasticsearch.index.store.Store;

server/src/main/java/org/elasticsearch/index/analysis/Analysis.java

@@ -56,7 +56,6 @@
 import org.apache.lucene.analysis.tr.TurkishAnalyzer;
 import org.apache.lucene.util.Version;
 import org.elasticsearch.common.Strings;
-import org.elasticsearch.common.io.FileSystemUtils;
 import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.logging.ESLoggerFactory;
 import org.elasticsearch.common.lucene.Lucene;

server/src/main/java/org/elasticsearch/index/engine/DeleteFailedEngineException.java

@@ -20,7 +20,6 @@
 package org.elasticsearch.index.engine;
 
 import org.elasticsearch.common.io.stream.StreamInput;
-import org.elasticsearch.index.shard.ShardId;
 
 import java.io.IOException;
 
@@ -34,4 +33,4 @@ public class DeleteFailedEngineException extends EngineException {
     public DeleteFailedEngineException(StreamInput in) throws IOException{
         super(in);
     }
-}
+}

server/src/main/java/org/elasticsearch/index/engine/IndexFailedEngineException.java

@@ -21,10 +21,8 @@
 
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
-import org.elasticsearch.index.shard.ShardId;
 
 import java.io.IOException;
-import java.util.Objects;
 
 /**
  * Deprecated as not used in 6.0, should be removed in 7.0
@@ -58,4 +56,4 @@ public String type() {
     public String id() {
         return this.id;
     }
-}
+}

server/src/main/java/org/elasticsearch/index/mapper/GeoShapeFieldMapper.java

@@ -30,7 +30,6 @@
 import org.apache.lucene.spatial.prefix.tree.PackedQuadPrefixTree;
 import org.apache.lucene.spatial.prefix.tree.QuadPrefixTree;
 import org.apache.lucene.spatial.prefix.tree.SpatialPrefixTree;
-import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.Version;
 import org.elasticsearch.common.Explicit;
 import org.elasticsearch.common.geo.GeoUtils;

server/src/main/java/org/elasticsearch/index/mapper/MappedFieldType.java

@@ -30,7 +30,6 @@
 import org.apache.lucene.search.BooleanQuery;
 import org.apache.lucene.search.BoostQuery;
 import org.apache.lucene.search.ConstantScoreQuery;
-import org.apache.lucene.search.MatchNoDocsQuery;
 import org.apache.lucene.search.MultiTermQuery;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.TermInSetQuery;
@@ -39,8 +38,6 @@
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.geo.ShapeRelation;
 import org.elasticsearch.common.joda.DateMathParser;
-import org.elasticsearch.common.logging.DeprecationLogger;
-import org.elasticsearch.common.logging.Loggers;
 import org.elasticsearch.common.lucene.all.AllTermQuery;
 import org.elasticsearch.common.unit.Fuzziness;
 import org.elasticsearch.index.analysis.NamedAnalyzer;

server/src/main/java/org/elasticsearch/index/mapper/StringFieldType.java

@@ -24,7 +24,6 @@
 import java.util.List;
 
 import org.apache.lucene.analysis.TokenStream;
-import org.apache.lucene.analysis.shingle.FixedShingleFilter;
 import org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute;
 import org.apache.lucene.analysis.tokenattributes.TermToBytesRefAttribute;
 import org.apache.lucene.index.Term;

server/src/main/java/org/elasticsearch/index/mapper/TextFieldMapper.java

@@ -28,22 +28,17 @@
 import org.apache.lucene.analysis.ngram.EdgeNGramTokenFilter;
 import org.apache.lucene.analysis.shingle.FixedShingleFilter;
 import org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute;
-import org.apache.lucene.analysis.tokenattributes.TermToBytesRefAttribute;
 import org.apache.lucene.document.Field;
-import org.apache.lucene.document.FieldType;
 import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.IndexableField;
 import org.apache.lucene.index.Term;
 import org.apache.lucene.search.ConstantScoreQuery;
-import org.apache.lucene.search.MultiPhraseQuery;
 import org.apache.lucene.search.MultiTermQuery;
 import org.apache.lucene.search.NormsFieldExistsQuery;
-import org.apache.lucene.search.PhraseQuery;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.TermQuery;
 import org.elasticsearch.Version;
 import org.elasticsearch.common.collect.Iterators;
-import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.logging.ESLoggerFactory;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentBuilder;

server/src/main/java/org/elasticsearch/index/query/ScriptQueryBuilder.java

@@ -36,7 +36,6 @@
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.script.FilterScript;
 import org.elasticsearch.script.Script;
-import org.elasticsearch.script.SearchScript;
 
 import java.io.IOException;
 import java.util.Objects;

server/src/main/java/org/elasticsearch/index/query/TypeQueryBuilder.java

@@ -27,7 +27,6 @@
 import org.elasticsearch.common.ParsingException;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
-import org.elasticsearch.common.lucene.BytesRefs;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.mapper.DocumentMapper;

server/src/main/java/org/elasticsearch/index/search/MatchQuery.java

@@ -54,7 +54,6 @@
 import org.elasticsearch.common.lucene.search.MultiPhrasePrefixQuery;
 import org.elasticsearch.common.lucene.search.Queries;
 import org.elasticsearch.common.unit.Fuzziness;
-import org.elasticsearch.index.analysis.ShingleTokenFilterFactory;
 import org.elasticsearch.index.mapper.KeywordFieldMapper;
 import org.elasticsearch.index.mapper.MappedFieldType;
 import org.elasticsearch.index.query.QueryShardContext;
@@ -65,7 +64,7 @@
 import static org.elasticsearch.common.lucene.search.Queries.newLenientFieldQuery;
 import static org.elasticsearch.common.lucene.search.Queries.newUnmappedFieldQuery;
 
-public class MatchQuery {
+public class    MatchQuery {
 
     private static final DeprecationLogger DEPRECATION_LOGGER = new DeprecationLogger(Loggers.getLogger(MappedFieldType.class));
 
@@ -418,9 +417,9 @@ protected Query createFieldQuery(Analyzer analyzer, BooleanClause.Occur operator
             // query based on the analysis chain.
             try (TokenStream source = analyzer.tokenStream(field, queryText)) {
                 if (source.hasAttribute(DisableGraphAttribute.class)) {
-                    /**
-                     * A {@link TokenFilter} in this {@link TokenStream} disabled the graph analysis to avoid
-                     * paths explosion. See {@link ShingleTokenFilterFactory} for details.
+                    /*
+                      A {@link TokenFilter} in this {@link TokenStream} disabled the graph analysis to avoid
+                      paths explosion. See {@link org.elasticsearch.index.analysis.ShingleTokenFilterFactory} for details.
                      */
                     setEnableGraphQueries(false);
                 }