Resolve Compiler and Test Failures in 2.x Branch Due to OpenSearch Co…

…re Refactoring (#946) In this commit, several issues causing compiler and test failures in the 2.x branch are addressed. The failures were introduced due to various refactoring activities in OpenSearch core. The changes made include: - For the usages of Strings.isEmpty or Strings.isNullOrEmpty method, use org.opensearch.core.common.Strings. - For the usages of Strings.toString method, use org.opensearch.common.Strings. - Update references to getExceptionName method in OpenSearchException, which is now moved to the BaseExceptionsHelper class. - Create a new version of coalesceToEmpty in response to its removal from the Strings class. - Substitute ImmutableOpenMap with HashMap for more efficient data handling. Testing has been conducted by running a successful Gradle build. Signed-off-by: Kaituo Li <[email protected]>
opensearch-project · Jul 10, 2023 · a5d1cf3 · a5d1cf3
1 parent dfb82ea
commit a5d1cf3
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Showing 36 changed files with 112 additions and 108 deletions.
diff --git a/src/main/java/org/opensearch/ad/caching/PriorityCache.java b/src/main/java/org/opensearch/ad/caching/PriorityCache.java
@@ -58,10 +58,10 @@
 import org.opensearch.ad.settings.EnabledSetting;
 import org.opensearch.ad.util.DateUtils;
 import org.opensearch.cluster.service.ClusterService;
-import org.opensearch.common.Strings;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.core.common.Strings;
 import org.opensearch.threadpool.ThreadPool;
 
 import com.google.common.cache.Cache;

diff --git a/src/main/java/org/opensearch/ad/common/exception/NotSerializedADExceptionName.java b/src/main/java/org/opensearch/ad/common/exception/NotSerializedADExceptionName.java
@@ -11,12 +11,13 @@
 
 package org.opensearch.ad.common.exception;
 
+import static org.opensearch.OpenSearchException.getExceptionName;
+
 import java.util.Optional;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.message.ParameterizedMessage;
-import org.opensearch.OpenSearchException;
 import org.opensearch.common.io.stream.NotSerializableExceptionWrapper;
 
 /**
@@ -29,16 +30,16 @@
  */
 public enum NotSerializedADExceptionName {
 
-    RESOURCE_NOT_FOUND_EXCEPTION_NAME_UNDERSCORE(OpenSearchException.getExceptionName(new ResourceNotFoundException("", ""))),
-    LIMIT_EXCEEDED_EXCEPTION_NAME_UNDERSCORE(OpenSearchException.getExceptionName(new LimitExceededException("", "", false))),
-    END_RUN_EXCEPTION_NAME_UNDERSCORE(OpenSearchException.getExceptionName(new EndRunException("", "", false))),
-    ANOMALY_DETECTION_EXCEPTION_NAME_UNDERSCORE(OpenSearchException.getExceptionName(new AnomalyDetectionException("", ""))),
-    INTERNAL_FAILURE_NAME_UNDERSCORE(OpenSearchException.getExceptionName(new InternalFailure("", ""))),
-    CLIENT_EXCEPTION_NAME_UNDERSCORE(OpenSearchException.getExceptionName(new ClientException("", ""))),
-    CANCELLATION_EXCEPTION_NAME_UNDERSCORE(OpenSearchException.getExceptionName(new ADTaskCancelledException("", ""))),
-    DUPLICATE_TASK_EXCEPTION_NAME_UNDERSCORE(OpenSearchException.getExceptionName(new DuplicateTaskException(""))),
-    AD_VERSION_EXCEPTION_NAME_UNDERSCORE(OpenSearchException.getExceptionName(new ADVersionException(""))),
-    AD_VALIDATION_EXCEPTION_NAME_UNDERSCORE(OpenSearchException.getExceptionName(new ADValidationException("", null, null)));
+    RESOURCE_NOT_FOUND_EXCEPTION_NAME_UNDERSCORE(getExceptionName(new ResourceNotFoundException("", ""))),
+    LIMIT_EXCEEDED_EXCEPTION_NAME_UNDERSCORE(getExceptionName(new LimitExceededException("", "", false))),
+    END_RUN_EXCEPTION_NAME_UNDERSCORE(getExceptionName(new EndRunException("", "", false))),
+    ANOMALY_DETECTION_EXCEPTION_NAME_UNDERSCORE(getExceptionName(new AnomalyDetectionException("", ""))),
+    INTERNAL_FAILURE_NAME_UNDERSCORE(getExceptionName(new InternalFailure("", ""))),
+    CLIENT_EXCEPTION_NAME_UNDERSCORE(getExceptionName(new ClientException("", ""))),
+    CANCELLATION_EXCEPTION_NAME_UNDERSCORE(getExceptionName(new ADTaskCancelledException("", ""))),
+    DUPLICATE_TASK_EXCEPTION_NAME_UNDERSCORE(getExceptionName(new DuplicateTaskException(""))),
+    AD_VERSION_EXCEPTION_NAME_UNDERSCORE(getExceptionName(new ADVersionException(""))),
+    AD_VALIDATION_EXCEPTION_NAME_UNDERSCORE(getExceptionName(new ADValidationException("", null, null)));
 
     private static final Logger LOG = LogManager.getLogger(NotSerializedADExceptionName.class);
     private final String name;

diff --git a/src/main/java/org/opensearch/ad/indices/AnomalyDetectionIndices.java b/src/main/java/org/opensearch/ad/indices/AnomalyDetectionIndices.java
@@ -30,7 +30,6 @@
 import java.util.Arrays;
 import java.util.EnumMap;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -74,14 +73,14 @@
 import org.opensearch.cluster.metadata.AliasMetadata;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.service.ClusterService;
-import org.opensearch.common.Strings;
 import org.opensearch.common.bytes.BytesArray;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.xcontent.LoggingDeprecationHandler;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.commons.InjectSecurity;
+import org.opensearch.core.common.Strings;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -91,8 +90,6 @@
 import org.opensearch.threadpool.Scheduler;
 import org.opensearch.threadpool.ThreadPool;
 
-import com.carrotsearch.hppc.cursors.ObjectCursor;
-import com.carrotsearch.hppc.cursors.ObjectObjectCursor;
 import com.google.common.base.Charsets;
 import com.google.common.io.Resources;
 
@@ -759,8 +756,7 @@ void deleteOldHistoryIndices() {
         adminClient.cluster().state(clusterStateRequest, ActionListener.wrap(clusterStateResponse -> {
             String latestToDelete = null;
             long latest = Long.MIN_VALUE;
-            for (ObjectCursor<IndexMetadata> cursor : clusterStateResponse.getState().metadata().indices().values()) {
-                IndexMetadata indexMetaData = cursor.value;
+            for (IndexMetadata indexMetaData : clusterStateResponse.getState().metadata().indices().values()) {
                 long creationTime = indexMetaData.getCreationDate();
 
                 if ((Instant.now().toEpochMilli() - creationTime) > historyRetentionPeriod.millis()) {
@@ -986,10 +982,10 @@ private void shouldUpdateIndex(ADIndex index, ActionListener<Boolean> thenDo) {
                 .indicesOptions(IndicesOptions.lenientExpandOpenHidden());
             adminClient.indices().getAliases(getAliasRequest, ActionListener.wrap(getAliasResponse -> {
                 String concreteIndex = null;
-                for (ObjectObjectCursor<String, List<AliasMetadata>> entry : getAliasResponse.getAliases()) {
-                    if (false == entry.value.isEmpty()) {
+                for (Map.Entry<String, List<AliasMetadata>> entry : getAliasResponse.getAliases().entrySet()) {
+                    if (false == entry.getValue().isEmpty()) {
                         // we assume the alias map to one concrete index, thus we can return after finding one
-                        concreteIndex = entry.key;
+                        concreteIndex = entry.getKey();
                         break;
                     }
                 }
@@ -1137,9 +1133,7 @@ private void updateJobIndexSettingIfNecessary(IndexState jobIndexState, ActionLi
 
     private static Integer getIntegerSetting(GetSettingsResponse settingsResponse, String settingKey) {
         Integer value = null;
-        Iterator<Settings> iter = settingsResponse.getIndexToSettings().valuesIt();
-        while (iter.hasNext()) {
-            Settings settings = iter.next();
+        for (Settings settings : settingsResponse.getIndexToSettings().values()) {
             value = settings.getAsInt(settingKey, null);
             if (value != null) {
                 break;
@@ -1150,9 +1144,7 @@ private static Integer getIntegerSetting(GetSettingsResponse settingsResponse, S
 
     private static String getStringSetting(GetSettingsResponse settingsResponse, String settingKey) {
         String value = null;
-        Iterator<Settings> iter = settingsResponse.getIndexToSettings().valuesIt();
-        while (iter.hasNext()) {
-            Settings settings = iter.next();
+        for (Settings settings : settingsResponse.getIndexToSettings().values()) {
             value = settings.get(settingKey, null);
             if (value != null) {
                 break;

diff --git a/src/main/java/org/opensearch/ad/model/AnomalyDetectorExecutionInput.java b/src/main/java/org/opensearch/ad/model/AnomalyDetectorExecutionInput.java
@@ -18,7 +18,7 @@
 
 import org.opensearch.ad.annotation.Generated;
 import org.opensearch.ad.util.ParseUtils;
-import org.opensearch.common.Strings;
+import org.opensearch.core.common.Strings;
 import org.opensearch.core.xcontent.ToXContentObject;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.core.xcontent.XContentParser;

diff --git a/src/main/java/org/opensearch/ad/ratelimit/CheckPointMaintainRequestAdapter.java b/src/main/java/org/opensearch/ad/ratelimit/CheckPointMaintainRequestAdapter.java
@@ -27,10 +27,10 @@
 import org.opensearch.ad.ml.ModelState;
 import org.opensearch.ad.util.DateUtils;
 import org.opensearch.cluster.service.ClusterService;
-import org.opensearch.common.Strings;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.core.common.Strings;
 
 public class CheckPointMaintainRequestAdapter {
     private static final Logger LOG = LogManager.getLogger(CheckPointMaintainRequestAdapter.class);

diff --git a/src/main/java/org/opensearch/ad/ratelimit/CheckpointWriteWorker.java b/src/main/java/org/opensearch/ad/ratelimit/CheckpointWriteWorker.java
@@ -39,9 +39,9 @@
 import org.opensearch.ad.model.AnomalyDetector;
 import org.opensearch.ad.util.ExceptionUtil;
 import org.opensearch.cluster.service.ClusterService;
-import org.opensearch.common.Strings;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.core.common.Strings;
 import org.opensearch.threadpool.ThreadPool;
 
 public class CheckpointWriteWorker extends BatchWorker<CheckpointWriteRequest, BulkRequest, BulkResponse> {

diff --git a/src/main/java/org/opensearch/ad/rest/RestGetAnomalyDetectorAction.java b/src/main/java/org/opensearch/ad/rest/RestGetAnomalyDetectorAction.java
@@ -30,7 +30,7 @@
 import org.opensearch.ad.transport.GetAnomalyDetectorAction;
 import org.opensearch.ad.transport.GetAnomalyDetectorRequest;
 import org.opensearch.client.node.NodeClient;
-import org.opensearch.common.Strings;
+import org.opensearch.core.common.Strings;
 import org.opensearch.rest.BaseRestHandler;
 import org.opensearch.rest.RestRequest;
 import org.opensearch.rest.action.RestActions;

diff --git a/src/main/java/org/opensearch/ad/rest/RestPreviewAnomalyDetectorAction.java b/src/main/java/org/opensearch/ad/rest/RestPreviewAnomalyDetectorAction.java
@@ -28,7 +28,7 @@
 import org.opensearch.ad.transport.PreviewAnomalyDetectorAction;
 import org.opensearch.ad.transport.PreviewAnomalyDetectorRequest;
 import org.opensearch.ad.util.RestHandlerUtils;
-import org.opensearch.common.Strings;
+import org.opensearch.core.common.Strings;
 import org.opensearch.core.xcontent.XContentParser;
 import org.opensearch.rest.BaseRestHandler;
 import org.opensearch.rest.BytesRestResponse;

diff --git a/src/main/java/org/opensearch/ad/rest/RestStatsAnomalyDetectorAction.java b/src/main/java/org/opensearch/ad/rest/RestStatsAnomalyDetectorAction.java
@@ -29,7 +29,7 @@
 import org.opensearch.client.node.NodeClient;
 import org.opensearch.cluster.node.DiscoveryNode;
 import org.opensearch.cluster.service.ClusterService;
-import org.opensearch.common.Strings;
+import org.opensearch.core.common.Strings;
 import org.opensearch.rest.BaseRestHandler;
 import org.opensearch.rest.RestRequest;
 import org.opensearch.rest.action.RestToXContentListener;

diff --git a/src/main/java/org/opensearch/ad/transport/ADBatchAnomalyResultRequest.java b/src/main/java/org/opensearch/ad/transport/ADBatchAnomalyResultRequest.java
@@ -19,9 +19,9 @@
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.ad.model.ADTask;
 import org.opensearch.ad.model.AnomalyDetector;
-import org.opensearch.common.Strings;
 import org.opensearch.common.io.stream.StreamInput;
 import org.opensearch.common.io.stream.StreamOutput;
+import org.opensearch.core.common.Strings;
 
 public class ADBatchAnomalyResultRequest extends ActionRequest {
     private ADTask adTask;

diff --git a/src/main/java/org/opensearch/ad/transport/ADCancelTaskRequest.java b/src/main/java/org/opensearch/ad/transport/ADCancelTaskRequest.java
@@ -19,9 +19,9 @@
 import org.opensearch.action.support.nodes.BaseNodesRequest;
 import org.opensearch.ad.constant.CommonErrorMessages;
 import org.opensearch.cluster.node.DiscoveryNode;
-import org.opensearch.common.Strings;
 import org.opensearch.common.io.stream.StreamInput;
 import org.opensearch.common.io.stream.StreamOutput;
+import org.opensearch.core.common.Strings;
 
 public class ADCancelTaskRequest extends BaseNodesRequest<ADCancelTaskRequest> {
 

diff --git a/src/main/java/org/opensearch/ad/transport/ADTaskProfileRequest.java b/src/main/java/org/opensearch/ad/transport/ADTaskProfileRequest.java
@@ -19,9 +19,9 @@
 import org.opensearch.action.support.nodes.BaseNodesRequest;
 import org.opensearch.ad.constant.CommonErrorMessages;
 import org.opensearch.cluster.node.DiscoveryNode;
-import org.opensearch.common.Strings;
 import org.opensearch.common.io.stream.StreamInput;
 import org.opensearch.common.io.stream.StreamOutput;
+import org.opensearch.core.common.Strings;
 
 public class ADTaskProfileRequest extends BaseNodesRequest<ADTaskProfileRequest> {
 

diff --git a/src/main/java/org/opensearch/ad/transport/AnomalyResultRequest.java b/src/main/java/org/opensearch/ad/transport/AnomalyResultRequest.java
@@ -22,11 +22,11 @@
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.ad.constant.CommonErrorMessages;
 import org.opensearch.ad.constant.CommonName;
-import org.opensearch.common.Strings;
 import org.opensearch.common.io.stream.InputStreamStreamInput;
 import org.opensearch.common.io.stream.OutputStreamStreamOutput;
 import org.opensearch.common.io.stream.StreamInput;
 import org.opensearch.common.io.stream.StreamOutput;
+import org.opensearch.core.common.Strings;
 import org.opensearch.core.xcontent.ToXContentObject;
 import org.opensearch.core.xcontent.XContentBuilder;
 

diff --git a/src/main/java/org/opensearch/ad/transport/DeleteAnomalyDetectorRequest.java b/src/main/java/org/opensearch/ad/transport/DeleteAnomalyDetectorRequest.java
@@ -18,9 +18,9 @@
 import org.opensearch.action.ActionRequest;
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.ad.constant.CommonErrorMessages;
-import org.opensearch.common.Strings;
 import org.opensearch.common.io.stream.StreamInput;
 import org.opensearch.common.io.stream.StreamOutput;
+import org.opensearch.core.common.Strings;
 
 public class DeleteAnomalyDetectorRequest extends ActionRequest {
 

diff --git a/src/main/java/org/opensearch/ad/transport/DeleteModelRequest.java b/src/main/java/org/opensearch/ad/transport/DeleteModelRequest.java
@@ -20,9 +20,9 @@
 import org.opensearch.ad.constant.CommonErrorMessages;
 import org.opensearch.ad.constant.CommonName;
 import org.opensearch.cluster.node.DiscoveryNode;
-import org.opensearch.common.Strings;
 import org.opensearch.common.io.stream.StreamInput;
 import org.opensearch.common.io.stream.StreamOutput;
+import org.opensearch.core.common.Strings;
 import org.opensearch.core.xcontent.ToXContentObject;
 import org.opensearch.core.xcontent.XContentBuilder;
 

diff --git a/src/main/java/org/opensearch/ad/transport/EntityProfileRequest.java b/src/main/java/org/opensearch/ad/transport/EntityProfileRequest.java
@@ -24,9 +24,9 @@
 import org.opensearch.ad.model.Entity;
 import org.opensearch.ad.model.EntityProfileName;
 import org.opensearch.ad.util.Bwc;
-import org.opensearch.common.Strings;
 import org.opensearch.common.io.stream.StreamInput;
 import org.opensearch.common.io.stream.StreamOutput;
+import org.opensearch.core.common.Strings;
 import org.opensearch.core.xcontent.ToXContentObject;
 import org.opensearch.core.xcontent.XContentBuilder;
 

diff --git a/src/main/java/org/opensearch/ad/transport/EntityResultRequest.java b/src/main/java/org/opensearch/ad/transport/EntityResultRequest.java
@@ -26,9 +26,9 @@
 import org.opensearch.ad.constant.CommonName;
 import org.opensearch.ad.model.Entity;
 import org.opensearch.ad.util.Bwc;
-import org.opensearch.common.Strings;
 import org.opensearch.common.io.stream.StreamInput;
 import org.opensearch.common.io.stream.StreamOutput;
+import org.opensearch.core.common.Strings;
 import org.opensearch.core.xcontent.ToXContentObject;
 import org.opensearch.core.xcontent.XContentBuilder;
 

diff --git a/src/main/java/org/opensearch/ad/transport/GetAnomalyDetectorTransportAction.java b/src/main/java/org/opensearch/ad/transport/GetAnomalyDetectorTransportAction.java
@@ -62,11 +62,11 @@
 import org.opensearch.client.Client;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.CheckedConsumer;
-import org.opensearch.common.Strings;
 import org.opensearch.common.inject.Inject;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.concurrent.ThreadContext;
 import org.opensearch.commons.authuser.User;
+import org.opensearch.core.common.Strings;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.core.xcontent.XContentParser;
 import org.opensearch.rest.RestStatus;

diff --git a/src/main/java/org/opensearch/ad/transport/RCFPollingRequest.java b/src/main/java/org/opensearch/ad/transport/RCFPollingRequest.java
@@ -19,9 +19,9 @@
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.ad.constant.CommonErrorMessages;
 import org.opensearch.ad.constant.CommonName;
-import org.opensearch.common.Strings;
 import org.opensearch.common.io.stream.StreamInput;
 import org.opensearch.common.io.stream.StreamOutput;
+import org.opensearch.core.common.Strings;
 import org.opensearch.core.xcontent.ToXContentObject;
 import org.opensearch.core.xcontent.XContentBuilder;
 

diff --git a/src/main/java/org/opensearch/ad/transport/RCFResultRequest.java b/src/main/java/org/opensearch/ad/transport/RCFResultRequest.java
@@ -19,9 +19,9 @@
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.ad.constant.CommonErrorMessages;
 import org.opensearch.ad.constant.CommonName;
-import org.opensearch.common.Strings;
 import org.opensearch.common.io.stream.StreamInput;
 import org.opensearch.common.io.stream.StreamOutput;
+import org.opensearch.core.common.Strings;
 import org.opensearch.core.xcontent.ToXContentObject;
 import org.opensearch.core.xcontent.XContentBuilder;
 

diff --git a/src/main/java/org/opensearch/ad/transport/SearchTopAnomalyResultTransportAction.java b/src/main/java/org/opensearch/ad/transport/SearchTopAnomalyResultTransportAction.java
@@ -39,8 +39,8 @@
 import org.opensearch.ad.model.AnomalyResultBucket;
 import org.opensearch.ad.transport.handler.ADSearchHandler;
 import org.opensearch.client.Client;
-import org.opensearch.common.Strings;
 import org.opensearch.common.inject.Inject;
+import org.opensearch.core.common.Strings;
 import org.opensearch.index.query.BoolQueryBuilder;
 import org.opensearch.index.query.ExistsQueryBuilder;
 import org.opensearch.index.query.QueryBuilder;

diff --git a/src/main/java/org/opensearch/ad/transport/StopDetectorRequest.java b/src/main/java/org/opensearch/ad/transport/StopDetectorRequest.java
@@ -21,11 +21,11 @@
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.ad.constant.CommonErrorMessages;
 import org.opensearch.ad.constant.CommonName;
-import org.opensearch.common.Strings;
 import org.opensearch.common.io.stream.InputStreamStreamInput;
 import org.opensearch.common.io.stream.OutputStreamStreamOutput;
 import org.opensearch.common.io.stream.StreamInput;
 import org.opensearch.common.io.stream.StreamOutput;
+import org.opensearch.core.common.Strings;
 import org.opensearch.core.xcontent.ToXContentObject;
 import org.opensearch.core.xcontent.XContentBuilder;
 

diff --git a/src/main/java/org/opensearch/ad/transport/ThresholdResultRequest.java b/src/main/java/org/opensearch/ad/transport/ThresholdResultRequest.java
@@ -19,9 +19,9 @@
 import org.opensearch.action.ActionRequestValidationException;
 import org.opensearch.ad.constant.CommonErrorMessages;
 import org.opensearch.ad.constant.CommonName;
-import org.opensearch.common.Strings;
 import org.opensearch.common.io.stream.StreamInput;
 import org.opensearch.common.io.stream.StreamOutput;
+import org.opensearch.core.common.Strings;
 import org.opensearch.core.xcontent.ToXContentObject;
 import org.opensearch.core.xcontent.XContentBuilder;
 

diff --git a/src/main/java/org/opensearch/ad/util/ADSafeSecurityInjector.java b/src/main/java/org/opensearch/ad/util/ADSafeSecurityInjector.java
@@ -19,10 +19,10 @@
 import org.opensearch.ad.NodeStateManager;
 import org.opensearch.ad.common.exception.EndRunException;
 import org.opensearch.ad.model.AnomalyDetector;
-import org.opensearch.common.Strings;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.concurrent.ThreadContext;
 import org.opensearch.commons.authuser.User;
+import org.opensearch.core.common.Strings;
 
 public class ADSafeSecurityInjector extends SafeSecurityInjector {
     private static final Logger LOG = LogManager.getLogger(ADSafeSecurityInjector.class);

diff --git a/src/main/java/org/opensearch/ad/util/RestHandlerUtils.java b/src/main/java/org/opensearch/ad/util/RestHandlerUtils.java
@@ -31,6 +31,7 @@
 import org.opensearch.ad.constant.CommonErrorMessages;
 import org.opensearch.ad.model.AnomalyDetector;
 import org.opensearch.ad.model.Feature;
+import org.opensearch.common.Nullable;
 import org.opensearch.common.Strings;
 import org.opensearch.common.bytes.BytesReference;
 import org.opensearch.common.xcontent.LoggingDeprecationHandler;
@@ -96,7 +97,7 @@ private RestHandlerUtils() {}
      * @return instance of {@link org.opensearch.search.fetch.subphase.FetchSourceContext}
      */
     public static FetchSourceContext getSourceContext(RestRequest request, SearchSourceBuilder searchSourceBuilder) {
-        String userAgent = Strings.coalesceToEmpty(request.header("User-Agent"));
+        String userAgent = coalesceToEmpty(request.header("User-Agent"));
 
         // If there is a _source given in request than we either add UI_Metadata to exclude or not depending on if request
         // is from OpenSearch-Dashboards, if no _source field then we either exclude UI_metadata or return nothing at all.
@@ -238,4 +239,8 @@ public static boolean isProperExceptionToReturn(Throwable e) {
         }
         return e instanceof OpenSearchStatusException || e instanceof IndexNotFoundException || e instanceof InvalidIndexNameException;
     }
+
+    private static String coalesceToEmpty(@Nullable String s) {
+        return s == null ? "" : s;
+    }
 }
diff --git a/src/test/java/org/opensearch/EntityProfileRequest1_0.java b/src/test/java/org/opensearch/EntityProfileRequest1_0.java
@@ -22,9 +22,9 @@
 import org.opensearch.ad.constant.CommonErrorMessages;
 import org.opensearch.ad.constant.CommonName;
 import org.opensearch.ad.model.EntityProfileName;
-import org.opensearch.common.Strings;
 import org.opensearch.common.io.stream.StreamInput;
 import org.opensearch.common.io.stream.StreamOutput;
+import org.opensearch.core.common.Strings;
 import org.opensearch.core.xcontent.ToXContentObject;
 import org.opensearch.core.xcontent.XContentBuilder;