diff --git a/common/src/java/org/apache/hadoop/hive/common/HiveStatsUtils.java b/common/src/java/org/apache/hadoop/hive/common/HiveStatsUtils.java index 09343e5616..389db6fa7c 100644 --- a/common/src/java/org/apache/hadoop/hive/common/HiveStatsUtils.java +++ b/common/src/java/org/apache/hadoop/hive/common/HiveStatsUtils.java @@ -19,6 +19,7 @@ import java.io.IOException; import java.util.ArrayList; +import java.util.Collections; import java.util.LinkedList; import java.util.List; @@ -79,7 +80,7 @@ // does not exist. But getFileStatus() throw IOException. To mimic the // similar behavior we will return empty array on exception. For external // tables, the path of the table will not exists during table creation - return new ArrayList<>(0); + return Collections.emptyList(); } return result; } diff --git a/hcatalog/webhcat/java-client/src/main/java/org/apache/hive/hcatalog/api/HCatClientHMSImpl.java b/hcatalog/webhcat/java-client/src/main/java/org/apache/hive/hcatalog/api/HCatClientHMSImpl.java index 1cb35bbd06..e8c7c54710 100644 --- a/hcatalog/webhcat/java-client/src/main/java/org/apache/hive/hcatalog/api/HCatClientHMSImpl.java +++ b/hcatalog/webhcat/java-client/src/main/java/org/apache/hive/hcatalog/api/HCatClientHMSImpl.java @@ -21,6 +21,7 @@ import java.io.IOException; import java.util.ArrayList; import java.util.Arrays; +import java.util.Collections; import java.util.Iterator; import java.util.List; import java.util.Map; @@ -1007,7 +1008,7 @@ public HCatNotificationEvent apply(@Nullable NotificationEvent notificationEvent } }); } else { - return new ArrayList(); + return Collections.emptyList(); } } catch (TException e) { throw new ConnectionFailureException("TException while getting notifications", e); diff --git a/hcatalog/webhcat/svr/src/main/java/org/apache/hive/hcatalog/templeton/tool/ZooKeeperCleanup.java b/hcatalog/webhcat/svr/src/main/java/org/apache/hive/hcatalog/templeton/tool/ZooKeeperCleanup.java index 4ebc34b549..ecf3ef552d 100644 --- a/hcatalog/webhcat/svr/src/main/java/org/apache/hive/hcatalog/templeton/tool/ZooKeeperCleanup.java +++ b/hcatalog/webhcat/svr/src/main/java/org/apache/hive/hcatalog/templeton/tool/ZooKeeperCleanup.java @@ -19,7 +19,6 @@ package org.apache.hive.hcatalog.templeton.tool; import java.io.IOException; -import java.util.ArrayList; import java.util.Collections; import java.util.List; import java.util.Date; @@ -138,7 +137,7 @@ public void run() { } catch (IOException e) { LOG.info("No jobs to check."); } - return new ArrayList(); + return Collections.emptyList(); } /** diff --git a/hcatalog/webhcat/svr/src/main/java/org/apache/hive/hcatalog/templeton/tool/ZooKeeperStorage.java b/hcatalog/webhcat/svr/src/main/java/org/apache/hive/hcatalog/templeton/tool/ZooKeeperStorage.java index 1fc8d36394..939c323ce6 100644 --- a/hcatalog/webhcat/svr/src/main/java/org/apache/hive/hcatalog/templeton/tool/ZooKeeperStorage.java +++ b/hcatalog/webhcat/svr/src/main/java/org/apache/hive/hcatalog/templeton/tool/ZooKeeperStorage.java @@ -20,6 +20,7 @@ import java.io.IOException; import java.util.ArrayList; +import java.util.Collections; import java.util.List; import org.slf4j.Logger; @@ -278,7 +279,7 @@ public boolean delete(Type type, String id) throws NotFoundException { try { return zk.getChildren().forPath(getPath(type)); } catch (Exception e) { - return new ArrayList(); + return Collections.emptyList(); } } diff --git a/kudu-handler/src/java/org/apache/hadoop/hive/kudu/KuduPredicateHandler.java b/kudu-handler/src/java/org/apache/hadoop/hive/kudu/KuduPredicateHandler.java index 4807f5304a..5168b455a3 100644 --- a/kudu-handler/src/java/org/apache/hadoop/hive/kudu/KuduPredicateHandler.java +++ b/kudu-handler/src/java/org/apache/hadoop/hive/kudu/KuduPredicateHandler.java @@ -119,7 +119,7 @@ private static IndexPredicateAnalyzer newAnalyzer(Schema schema) { public static List getPredicates(Configuration conf, Schema schema) { SearchArgument sarg = ConvertAstToSearchArg.createFromConf(conf); if (sarg == null) { - return new ArrayList<>(); + return Collections.emptyList(); } return toKuduPredicates(sarg, schema); } diff --git a/ql/src/java/org/apache/hadoop/hive/ql/exec/SerializationUtilities.java b/ql/src/java/org/apache/hadoop/hive/ql/exec/SerializationUtilities.java index e205c08d84..b10954fd4f 100644 --- a/ql/src/java/org/apache/hadoop/hive/ql/exec/SerializationUtilities.java +++ b/ql/src/java/org/apache/hadoop/hive/ql/exec/SerializationUtilities.java @@ -30,6 +30,7 @@ import java.time.ZoneId; import java.util.ArrayList; import java.util.Arrays; +import java.util.Collections; import java.util.HashMap; import java.util.LinkedList; import java.util.List; @@ -718,7 +719,7 @@ public static MapredWork clonePlan(MapredWork plan) { */ public static List> cloneOperatorTree(List> roots) { if (roots.isEmpty()) { - return new ArrayList<>(); + return Collections.emptyList(); } ByteArrayOutputStream baos = new ByteArrayOutputStream(4096); CompilationOpContext ctx = roots.get(0).getCompilationOpContext(); diff --git a/ql/src/java/org/apache/hadoop/hive/ql/exec/Utilities.java b/ql/src/java/org/apache/hadoop/hive/ql/exec/Utilities.java index a7770b4e53..27dbaab6b2 100644 --- a/ql/src/java/org/apache/hadoop/hive/ql/exec/Utilities.java +++ b/ql/src/java/org/apache/hadoop/hive/ql/exec/Utilities.java @@ -3935,7 +3935,7 @@ public static boolean isInputFileFormatVectorized(PartitionDesc pd) { String[] classNames = org.apache.hadoop.util.StringUtils.getStrings(HiveConf.getVar(hiveConf, confVar)); if (classNames == null) { - return new ArrayList<>(0); + return Collections.emptyList(); } Collection> classList = new ArrayList>(classNames.length); for (String className : classNames) { diff --git a/ql/src/java/org/apache/hadoop/hive/ql/exec/spark/SparkPlan.java b/ql/src/java/org/apache/hadoop/hive/ql/exec/spark/SparkPlan.java index 8244dcb1a9..20127b13b2 100644 --- a/ql/src/java/org/apache/hadoop/hive/ql/exec/spark/SparkPlan.java +++ b/ql/src/java/org/apache/hadoop/hive/ql/exec/spark/SparkPlan.java @@ -20,7 +20,7 @@ import java.io.ByteArrayOutputStream; import java.io.PrintStream; -import java.util.ArrayList; +import java.util.Collections; import java.util.HashMap; import java.util.HashSet; import java.util.LinkedList; @@ -31,7 +31,6 @@ import org.apache.commons.lang.StringUtils; import org.apache.hadoop.hive.conf.HiveConf; import org.apache.hadoop.hive.ql.exec.ExplainTask; -import org.apache.hadoop.hive.ql.exec.Utilities; import org.apache.hadoop.hive.ql.parse.ExplainConfiguration; import org.apache.hadoop.hive.ql.plan.ExplainWork; import org.apache.hadoop.mapred.JobConf; @@ -226,7 +225,7 @@ public void connect(SparkTran parent, SparkTran child) { public List getParents(SparkTran tran) { if (!invertedTransGraph.containsKey(tran)) { - return new ArrayList(); + return Collections.emptyList(); } return invertedTransGraph.get(tran); @@ -234,7 +233,7 @@ public void connect(SparkTran parent, SparkTran child) { public List getChildren(SparkTran tran) { if (!transGraph.containsKey(tran)) { - return new ArrayList(); + return Collections.emptyList(); } return transGraph.get(tran); diff --git a/ql/src/java/org/apache/hadoop/hive/ql/io/HiveFileFormatUtils.java b/ql/src/java/org/apache/hadoop/hive/ql/io/HiveFileFormatUtils.java index 8980a6292a..60bc063914 100644 --- a/ql/src/java/org/apache/hadoop/hive/ql/io/HiveFileFormatUtils.java +++ b/ql/src/java/org/apache/hadoop/hive/ql/io/HiveFileFormatUtils.java @@ -23,6 +23,7 @@ import java.nio.file.Files; import java.nio.file.Paths; import java.util.ArrayList; +import java.util.Collections; import java.util.HashMap; import java.util.Iterator; import java.util.LinkedList; @@ -475,7 +476,7 @@ private static Path getMatchingPath(Map> pathToAliases, Path **/ public static List doGetAliasesFromPath(Map> pathToAliases, Path dir) { if (pathToAliases == null) { - return new ArrayList(); + return Collections.emptyList(); } Path path = getMatchingPath(pathToAliases, dir); return pathToAliases.get(path); diff --git a/ql/src/java/org/apache/hadoop/hive/ql/metadata/Hive.java b/ql/src/java/org/apache/hadoop/hive/ql/metadata/Hive.java index 6143e85664..b6a14690a7 100644 --- a/ql/src/java/org/apache/hadoop/hive/ql/metadata/Hive.java +++ b/ql/src/java/org/apache/hadoop/hive/ql/metadata/Hive.java @@ -1627,8 +1627,7 @@ public Table apply(org.apache.hadoop.hive.metastore.api.Table table) { List materializedViews = HiveMaterializedViewsRegistry.get().getRewritingMaterializedViews(); if (materializedViews.isEmpty()) { - // Bail out: empty list - return new ArrayList<>(); + return Collections.emptyList(); } // Add to final result return filterAugmentMaterializedViews(materializedViews, tablesUsed, txnMgr); @@ -1774,8 +1773,7 @@ public boolean validateMaterializedViewsFromRegistry(List cachedMateriali List
materializedViewTables = getAllMaterializedViewObjectsForRewriting(); if (materializedViewTables.isEmpty()) { - // Bail out: empty list - return new ArrayList<>(); + Collections.emptyList(); } // Return final result return getValidMaterializedViews(materializedViewTables, tablesUsed, false, txnMgr); @@ -3804,7 +3802,7 @@ public boolean dropPartition(String dbName, String tableName, List parti private static List convertFromMetastore(Table tbl, List partitions) throws HiveException { if (partitions == null) { - return new ArrayList(); + Collections.emptyList(); } List results = new ArrayList(partitions.size()); diff --git a/ql/src/java/org/apache/hadoop/hive/ql/metadata/Partition.java b/ql/src/java/org/apache/hadoop/hive/ql/metadata/Partition.java index 136709c6dc..9326ea3b1b 100644 --- a/ql/src/java/org/apache/hadoop/hive/ql/metadata/Partition.java +++ b/ql/src/java/org/apache/hadoop/hive/ql/metadata/Partition.java @@ -21,6 +21,7 @@ import java.io.Serializable; import java.util.ArrayList; import java.util.Arrays; +import java.util.Collections; import java.util.HashMap; import java.util.LinkedHashMap; import java.util.List; @@ -511,7 +512,7 @@ public void setTPartition( tPartition.getSd().getSerdeInfo().getSerializationLib(), e); } - return new ArrayList(); + return Collections.emptyList(); } public String getLocation() { diff --git a/ql/src/java/org/apache/hadoop/hive/ql/metadata/Table.java b/ql/src/java/org/apache/hadoop/hive/ql/metadata/Table.java index 33a450585b..25c20b7909 100644 --- a/ql/src/java/org/apache/hadoop/hive/ql/metadata/Table.java +++ b/ql/src/java/org/apache/hadoop/hive/ql/metadata/Table.java @@ -22,6 +22,7 @@ import java.io.Serializable; import java.util.ArrayList; import java.util.Arrays; +import java.util.Collections; import java.util.HashMap; import java.util.HashSet; import java.util.LinkedHashMap; @@ -690,7 +691,7 @@ private boolean isField(String col) { } catch (Exception e) { LOG.error("Unable to get field from serde: " + serializationLib, e); } - return new ArrayList(); + return Collections.emptyList(); } /** diff --git a/ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/rules/HivePreFilteringRule.java b/ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/rules/HivePreFilteringRule.java index 33205a594f..c78e7a4234 100644 --- a/ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/rules/HivePreFilteringRule.java +++ b/ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/rules/HivePreFilteringRule.java @@ -18,6 +18,7 @@ package org.apache.hadoop.hive.ql.optimizer.calcite.rules; import java.util.ArrayList; +import java.util.Collections; import java.util.HashSet; import java.util.List; import java.util.Set; @@ -204,13 +205,13 @@ public void onMatch(RelOptRuleCall call) { for (RexNode conjunction : conjunctions) { // We do not know what it is, we bail out for safety if (!(conjunction instanceof RexCall) || !HiveCalciteUtil.isDeterministic(conjunction)) { - return new ArrayList<>(); + return Collections.emptyList(); } RexCall conjCall = (RexCall) conjunction; Set refs = HiveCalciteUtil.getInputRefs(conjCall); if (refs.size() != 1) { // We do not know what it is, we bail out for safety - return new ArrayList<>(); + return Collections.emptyList(); } RexNode ref = rexBuilder.makeInputRef(input, refs.iterator().next()); String stringRef = ref.toString(); @@ -227,7 +228,7 @@ public void onMatch(RelOptRuleCall call) { // If we did not add any factor or there are no common factors, we can // bail out if (refsInAllOperands.isEmpty()) { - return new ArrayList<>(); + return Collections.emptyList(); } } diff --git a/ql/src/java/org/apache/hadoop/hive/ql/plan/PlanUtils.java b/ql/src/java/org/apache/hadoop/hive/ql/plan/PlanUtils.java index e20f6956b2..155aa20fc3 100644 --- a/ql/src/java/org/apache/hadoop/hive/ql/plan/PlanUtils.java +++ b/ql/src/java/org/apache/hadoop/hive/ql/plan/PlanUtils.java @@ -657,7 +657,7 @@ public static TableDesc getReduceValueTableDesc(List fieldSchemas) public static List getFieldSchemasFromColumnInfo( List cols, String fieldPrefix) { if ((cols == null) || (cols.size() == 0)) { - return new ArrayList(); + return Collections.emptyList(); } List schemas = new ArrayList(cols.size()); diff --git a/ql/src/java/org/apache/hadoop/hive/ql/plan/ReduceSinkDesc.java b/ql/src/java/org/apache/hadoop/hive/ql/plan/ReduceSinkDesc.java index 9257375786..c7a9924294 100644 --- a/ql/src/java/org/apache/hadoop/hive/ql/plan/ReduceSinkDesc.java +++ b/ql/src/java/org/apache/hadoop/hive/ql/plan/ReduceSinkDesc.java @@ -20,6 +20,7 @@ import java.util.ArrayList; import java.util.Arrays; +import java.util.Collections; import java.util.EnumSet; import java.util.LinkedHashSet; import java.util.List; @@ -569,7 +570,7 @@ public ReduceSinkOperatorExplainVectorization(ReduceSinkDesc reduceSinkDesc, int[] keyColumnMap = vectorReduceSinkInfo.getReduceSinkKeyColumnMap(); if (keyColumnMap == null) { // Always show an array. - return new ArrayList(); + return Collections.emptyList(); } return outputColumnsAndTypesToStringList( vectorReduceSinkInfo.getReduceSinkKeyColumnMap(), @@ -585,7 +586,7 @@ public ReduceSinkOperatorExplainVectorization(ReduceSinkDesc reduceSinkDesc, int[] valueColumnMap = vectorReduceSinkInfo.getReduceSinkValueColumnMap(); if (valueColumnMap == null) { // Always show an array. - return new ArrayList(); + return Collections.emptyList(); } return outputColumnsAndTypesToStringList( vectorReduceSinkInfo.getReduceSinkValueColumnMap(), diff --git a/ql/src/java/org/apache/hadoop/hive/ql/stats/StatsUtils.java b/ql/src/java/org/apache/hadoop/hive/ql/stats/StatsUtils.java index 36c5cb7177..1edccc57a0 100644 --- a/ql/src/java/org/apache/hadoop/hive/ql/stats/StatsUtils.java +++ b/ql/src/java/org/apache/hadoop/hive/ql/stats/StatsUtils.java @@ -1046,8 +1046,8 @@ else if(colTypeLowerCase.equals(serdeConstants.SMALLINT_TYPE_NAME)){ } private static List convertColStats(List colStats, String tabName) { - if (colStats==null) { - return new ArrayList(); + if (colStats == null) { + return Collections.emptyList(); } List stats = new ArrayList(colStats.size()); for (ColumnStatisticsObj statObj : colStats) { diff --git a/serde/src/java/org/apache/hadoop/hive/serde2/NullStructSerDe.java b/serde/src/java/org/apache/hadoop/hive/serde2/NullStructSerDe.java index db08878944..09b7630d19 100644 --- a/serde/src/java/org/apache/hadoop/hive/serde2/NullStructSerDe.java +++ b/serde/src/java/org/apache/hadoop/hive/serde2/NullStructSerDe.java @@ -17,7 +17,7 @@ */ package org.apache.hadoop.hive.serde2; -import java.util.ArrayList; +import java.util.Collections; import java.util.List; import java.util.Properties; @@ -107,7 +107,7 @@ public StructField getStructFieldRef(String fieldName) { @Override public List getAllStructFieldRefs() { - return new ArrayList(); + return Collections.emptyList(); } @Override @@ -117,7 +117,7 @@ public Object getStructFieldData(Object data, StructField fieldRef) { @Override public List getStructFieldsDataAsList(Object data) { - return new ArrayList(); + return Collections.emptyList(); } } diff --git a/standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/utils/FileUtils.java b/standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/utils/FileUtils.java index bf206fffc2..e1032ad05a 100644 --- a/standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/utils/FileUtils.java +++ b/standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/utils/FileUtils.java @@ -334,7 +334,7 @@ public static String unescapePathName(String path) { // does not exist. But getFileStatus() throw IOException. To mimic the // similar behavior we will return empty array on exception. For external // tables, the path of the table will not exists during table creation - return new ArrayList<>(0); + return Collections.emptyList(); } return result; } diff --git a/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/HiveMetaStore.java b/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/HiveMetaStore.java index 94698e6771..13a2e772ad 100644 --- a/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/HiveMetaStore.java +++ b/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/HiveMetaStore.java @@ -6138,12 +6138,10 @@ public boolean drop_partition_by_name_with_environment_context(final String db_n @Override public List partition_name_to_vals(String part_name) throws TException { if (part_name.length() == 0) { - return new ArrayList<>(); + return Collections.emptyList(); } LinkedHashMap map = Warehouse.makeSpecFromName(part_name); - List part_vals = new ArrayList<>(); - part_vals.addAll(map.values()); - return part_vals; + return new ArrayList<>(map.values()); } @Override diff --git a/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/MetastoreDefaultTransformer.java b/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/MetastoreDefaultTransformer.java index 8d018d759f..c602dbda25 100644 --- a/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/MetastoreDefaultTransformer.java +++ b/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/MetastoreDefaultTransformer.java @@ -34,6 +34,7 @@ import java.util.ArrayList; import java.util.Arrays; +import java.util.Collections; import java.util.HashMap; import java.util.List; import java.util.Map; @@ -697,17 +698,17 @@ public Database transformDatabase(Database db, List processorCapabilitie return list1; if (list1 == null || list1.size() == 0) - return new ArrayList(); + return Collections.emptyList(); if (list2.containsAll(list1)) - return new ArrayList(); + return Collections.emptyList(); diffList.addAll(list2); LOG.debug("diffList=" + Arrays.toString(diffList.toArray()) + ",master list=" + Arrays.toString(list1.toArray())); if (diffList.retainAll(list1)) { LOG.debug("diffList=" + Arrays.toString(diffList.toArray())); if (diffList.size() == list1.size()) { // lists match - return new ArrayList(); // return empty list indicating no missing elements + return Collections.emptyList(); // return empty list indicating no missing elements } else { list1.removeAll(diffList); LOG.debug("list1.size():" + list1.size()); diff --git a/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/ObjectStore.java b/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/ObjectStore.java index fb9d87006c..7bfe1bd000 100644 --- a/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/ObjectStore.java +++ b/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/ObjectStore.java @@ -5689,7 +5689,7 @@ public PrincipalPrivilegeSet getUserPrivilegeSet(String userName, return grantInfos; } } - return new ArrayList<>(0); + return Collections.emptyList(); } @@ -5924,7 +5924,7 @@ private PrincipalType getPrincipalTypeFromStr(String str) { return grantInfos; } } - return new ArrayList<>(0); + return Collections.emptyList(); } private List getColumnPrivilege(String catName, String dbName, @@ -5967,7 +5967,7 @@ private PrincipalType getPrincipalTypeFromStr(String str) { return grantInfos; } } - return new ArrayList<>(0); + return Collections.emptyList(); } @Override diff --git a/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/utils/MetaStoreServerUtils.java b/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/utils/MetaStoreServerUtils.java index a30b6bf4f7..77c870512d 100644 --- a/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/utils/MetaStoreServerUtils.java +++ b/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/utils/MetaStoreServerUtils.java @@ -30,6 +30,7 @@ import java.security.MessageDigest; import java.util.ArrayList; import java.util.Collection; +import java.util.Collections; import java.util.HashMap; import java.util.List; import java.util.Map; @@ -181,7 +182,7 @@ public String apply(@Nullable String string) { if (colStatsMap.size() < 1) { LOG.debug("No stats data found for: tblName= {}, partNames= {}, colNames= {}", TableName.getQualified(catName, dbName, tableName), partNames, colNames); - return new ArrayList(); + return Collections.emptyList(); } return aggrPartitionStats(colStatsMap, partNames, areAllPartsFound, useDensityFunctionForNDVEstimation, ndvTuner);