From 56c63fa98d2c5b38d9da6b01395d69509446e272 Mon Sep 17 00:00:00 2001
From: zane-neo <zaniu@amazon.com>
Date: Tue, 8 Aug 2023 10:29:38 +0800
Subject: [PATCH] Use builder.toString() to get a builder string value and
 format code

Signed-off-by: zane-neo <zaniu@amazon.com>
---
 .../java/org/opensearch/ml/common/connector/Connector.java  | 3 +--
 .../java/org/opensearch/ml/common/utils/StringUtils.java    | 6 ------
 .../src/test/java/org/opensearch/ml/common/TestHelper.java  | 3 +--
 .../opensearch/ml/common/dataframe/BooleanValueTest.java    | 3 +--
 .../org/opensearch/ml/common/dataframe/ColumnMetaTest.java  | 3 +--
 .../ml/common/dataframe/DefaultDataFrameTest.java           | 3 +--
 .../org/opensearch/ml/common/dataframe/DoubleValueTest.java | 3 +--
 .../org/opensearch/ml/common/dataframe/FloatValueTest.java  | 3 +--
 .../org/opensearch/ml/common/dataframe/IntValueTest.java    | 3 +--
 .../org/opensearch/ml/common/dataframe/LongValueTest.java   | 3 +--
 .../org/opensearch/ml/common/dataframe/NullValueTest.java   | 3 +--
 .../java/org/opensearch/ml/common/dataframe/RowTest.java    | 3 +--
 .../org/opensearch/ml/common/dataframe/ShortValueTest.java  | 3 +--
 .../org/opensearch/ml/common/dataframe/StringValueTest.java | 3 +--
 .../java/org/opensearch/ml/common/input/MLInputTest.java    | 3 +--
 .../anomalylocalization/AnomalyLocalizationInputTests.java  | 5 ++---
 .../opensearch/ml/common/input/nlp/TextDocsMLInputTest.java | 3 +--
 .../opensearch/ml/common/output/MLPredictionOutputTest.java | 5 ++---
 .../opensearch/ml/common/output/MLTrainingOutputTest.java   | 3 +--
 .../anomalylocalization/AnomalyLocalizationOutputTests.java | 3 +--
 .../samplecalculator/LocalSampleCalculatorOutputTest.java   | 5 ++---
 .../ml/common/output/sample/SampleAlgoOutputTest.java       | 5 ++---
 .../transport/connector/MLConnectorGetResponseTests.java    | 3 +--
 .../transport/connector/MLCreateConnectorInputTests.java    | 5 ++---
 .../transport/deploy/MLDeployModelNodesResponseTest.java    | 3 +--
 .../common/transport/deploy/MLDeployModelResponseTest.java  | 3 +--
 .../common/transport/execute/MLExecuteTaskResponseTest.java | 3 +--
 .../ml/common/transport/forward/MLForwardResponseTest.java  | 3 +--
 .../ml/common/transport/model/MLModelGetResponseTest.java   | 3 +--
 .../transport/prediction/MLPredictionTaskResponseTest.java  | 3 +--
 .../common/transport/register/MLRegisterModelInputTest.java | 5 ++---
 .../transport/register/MLRegisterModelResponseTest.java     | 3 +--
 .../ml/common/transport/sync/MLSyncUpResponseTest.java      | 3 +--
 .../ml/common/transport/task/MLTaskGetResponseTest.java     | 3 +--
 .../common/transport/undeploy/MLUndeployModelInputTest.java | 3 +--
 .../undeploy/MLUndeployModelNodesResponseTest.java          | 3 +--
 .../transport/upload_chunk/MLUploadModelChunkInputTest.java | 3 +--
 .../ml/action/connector/TransportCreateConnectorAction.java | 2 +-
 .../org/opensearch/ml/action/handler/MLSearchHandler.java   | 3 +--
 .../action/model_group/TransportUpdateModelGroupAction.java | 2 +-
 .../org/opensearch/ml/helper/ModelAccessControlHelper.java  | 2 +-
 .../java/org/opensearch/ml/model/MLModelGroupManager.java   | 2 +-
 .../main/java/org/opensearch/ml/utils/MLExceptionUtils.java | 3 +--
 .../deploy/TransportDeployModelOnNodeActionTests.java       | 2 +-
 .../action/undeploy/TransportUndeployModelActionTests.java  | 2 +-
 .../ml/autoredeploy/MLModelAutoReDeployerTests.java         | 2 +-
 .../java/org/opensearch/ml/cluster/MLSyncUpCronTests.java   | 2 +-
 .../org/opensearch/ml/rest/RestMLProfileActionTests.java    | 2 +-
 .../java/org/opensearch/ml/rest/RestMLStatsActionTests.java | 2 +-
 .../test/java/org/opensearch/ml/utils/IntegTestUtils.java   | 3 +--
 .../src/test/java/org/opensearch/ml/utils/TestHelper.java   | 2 +-
 51 files changed, 56 insertions(+), 101 deletions(-)

diff --git a/common/src/main/java/org/opensearch/ml/common/connector/Connector.java b/common/src/main/java/org/opensearch/ml/common/connector/Connector.java
index 32d8ad78f4..19ed549db2 100644
--- a/common/src/main/java/org/opensearch/ml/common/connector/Connector.java
+++ b/common/src/main/java/org/opensearch/ml/common/connector/Connector.java
@@ -32,7 +32,6 @@
 import org.opensearch.ml.common.AccessMode;
 import org.opensearch.ml.common.MLCommonsClassLoader;
 import org.opensearch.ml.common.output.model.ModelTensor;
-import org.opensearch.ml.common.utils.StringUtils;
 
 /**
  * Connector defines how to connect to a remote service.
@@ -93,7 +92,7 @@ static Connector fromStream(StreamInput in) throws IOException {
     }
 
     static Connector createConnector(XContentBuilder builder, String connectorProtocol) throws IOException {
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         return createConnector(jsonStr, connectorProtocol);
     }
 
diff --git a/common/src/main/java/org/opensearch/ml/common/utils/StringUtils.java b/common/src/main/java/org/opensearch/ml/common/utils/StringUtils.java
index 34631b95b4..968cda1575 100644
--- a/common/src/main/java/org/opensearch/ml/common/utils/StringUtils.java
+++ b/common/src/main/java/org/opensearch/ml/common/utils/StringUtils.java
@@ -11,8 +11,6 @@
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
-import org.opensearch.core.common.bytes.BytesReference;
-import org.opensearch.core.xcontent.XContentBuilder;
 
 import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
@@ -84,8 +82,4 @@ public static Map<String, String> getParameterMap(Map<String, ?> parameterObjs)
         }
         return parameters;
     }
-
-    public static String xContentBuilderToString(XContentBuilder builder) {
-        return BytesReference.bytes(builder).utf8ToString();
-    }
 }
diff --git a/common/src/test/java/org/opensearch/ml/common/TestHelper.java b/common/src/test/java/org/opensearch/ml/common/TestHelper.java
index 0b72e790d6..81810aef92 100644
--- a/common/src/test/java/org/opensearch/ml/common/TestHelper.java
+++ b/common/src/test/java/org/opensearch/ml/common/TestHelper.java
@@ -14,7 +14,6 @@
 import org.opensearch.core.xcontent.ToXContentObject;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.core.xcontent.XContentParser;
-import org.opensearch.ml.common.utils.StringUtils;
 
 import java.io.IOException;
 import java.util.function.Function;
@@ -34,7 +33,7 @@ public static <T> void testParse(ToXContentObject obj, Function<XContentParser,
         if (wrapWithObject) {
             builder.endObject();
         }
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         testParseFromString(obj, jsonStr, function);
     }
 
diff --git a/common/src/test/java/org/opensearch/ml/common/dataframe/BooleanValueTest.java b/common/src/test/java/org/opensearch/ml/common/dataframe/BooleanValueTest.java
index 2735567129..d33564a1bc 100644
--- a/common/src/test/java/org/opensearch/ml/common/dataframe/BooleanValueTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/dataframe/BooleanValueTest.java
@@ -6,7 +6,6 @@
 package org.opensearch.ml.common.dataframe;
 
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
 
@@ -32,7 +31,7 @@ public void testToXContent() throws IOException {
         value.toXContent(builder);
 
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"column_type\":\"BOOLEAN\",\"value\":true}", jsonStr);
     }
 }
diff --git a/common/src/test/java/org/opensearch/ml/common/dataframe/ColumnMetaTest.java b/common/src/test/java/org/opensearch/ml/common/dataframe/ColumnMetaTest.java
index 9dc24a5622..0655ab9b3e 100644
--- a/common/src/test/java/org/opensearch/ml/common/dataframe/ColumnMetaTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/dataframe/ColumnMetaTest.java
@@ -7,7 +7,6 @@
 
 import org.junit.Before;
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -54,7 +53,7 @@ public void testToXContent() throws IOException {
         columnMeta.toXContent(builder);
 
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"name\":\"columnMetaName\",\"column_type\":\"STRING\"}", jsonStr);
     }
 
diff --git a/common/src/test/java/org/opensearch/ml/common/dataframe/DefaultDataFrameTest.java b/common/src/test/java/org/opensearch/ml/common/dataframe/DefaultDataFrameTest.java
index 9ce7f10b4c..eb1460f24e 100644
--- a/common/src/test/java/org/opensearch/ml/common/dataframe/DefaultDataFrameTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/dataframe/DefaultDataFrameTest.java
@@ -20,7 +20,6 @@
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.core.xcontent.XContentParser;
 import org.opensearch.ml.common.TestHelper;
-import org.opensearch.ml.common.utils.StringUtils;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
@@ -232,7 +231,7 @@ public void testToXContent() throws IOException {
         builder.endObject();
 
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"column_metas\":[" +
              "{\"name\":\"c1\",\"column_type\":\"STRING\"}," +
              "{\"name\":\"c2\",\"column_type\":\"INTEGER\"}," +
diff --git a/common/src/test/java/org/opensearch/ml/common/dataframe/DoubleValueTest.java b/common/src/test/java/org/opensearch/ml/common/dataframe/DoubleValueTest.java
index ae4ad0bb11..84e79a1561 100644
--- a/common/src/test/java/org/opensearch/ml/common/dataframe/DoubleValueTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/dataframe/DoubleValueTest.java
@@ -11,7 +11,6 @@
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
-import org.opensearch.ml.common.utils.StringUtils;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
@@ -50,7 +49,7 @@ public void testToXContent() throws IOException {
         doubleValue.toXContent(builder);
 
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"column_type\":\"DOUBLE\",\"value\":5.0}", jsonStr);
     }
 }
diff --git a/common/src/test/java/org/opensearch/ml/common/dataframe/FloatValueTest.java b/common/src/test/java/org/opensearch/ml/common/dataframe/FloatValueTest.java
index 31c87b57ad..ce30022bd2 100644
--- a/common/src/test/java/org/opensearch/ml/common/dataframe/FloatValueTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/dataframe/FloatValueTest.java
@@ -6,7 +6,6 @@
 package org.opensearch.ml.common.dataframe;
 
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
 
@@ -33,7 +32,7 @@ public void testToXContent() throws IOException {
         floatValue.toXContent(builder);
 
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"column_type\":\"FLOAT\",\"value\":2.1}", jsonStr);
     }
 }
diff --git a/common/src/test/java/org/opensearch/ml/common/dataframe/IntValueTest.java b/common/src/test/java/org/opensearch/ml/common/dataframe/IntValueTest.java
index a1a890826f..1c307ab1b9 100644
--- a/common/src/test/java/org/opensearch/ml/common/dataframe/IntValueTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/dataframe/IntValueTest.java
@@ -8,7 +8,6 @@
 import org.junit.Test;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
-import org.opensearch.ml.common.utils.StringUtils;
 
 import java.io.IOException;
 
@@ -32,7 +31,7 @@ public void testToXContent() throws IOException {
         intValue.toXContent(builder);
 
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"column_type\":\"INTEGER\",\"value\":2}", jsonStr);
     }
 }
diff --git a/common/src/test/java/org/opensearch/ml/common/dataframe/LongValueTest.java b/common/src/test/java/org/opensearch/ml/common/dataframe/LongValueTest.java
index 80d14bd5b3..0266c24fc5 100644
--- a/common/src/test/java/org/opensearch/ml/common/dataframe/LongValueTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/dataframe/LongValueTest.java
@@ -6,7 +6,6 @@
 package org.opensearch.ml.common.dataframe;
 
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
 
@@ -32,7 +31,7 @@ public void testToXContent() throws IOException {
         longValue.toXContent(builder);
 
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"column_type\":\"LONG\",\"value\":2}", jsonStr);
     }
 }
diff --git a/common/src/test/java/org/opensearch/ml/common/dataframe/NullValueTest.java b/common/src/test/java/org/opensearch/ml/common/dataframe/NullValueTest.java
index f7738923ce..a4c42424f4 100644
--- a/common/src/test/java/org/opensearch/ml/common/dataframe/NullValueTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/dataframe/NullValueTest.java
@@ -6,7 +6,6 @@
 package org.opensearch.ml.common.dataframe;
 
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -33,7 +32,7 @@ public void testToXContent() throws IOException {
         value.toXContent(builder, ToXContent.EMPTY_PARAMS);
 
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"column_type\":\"NULL\"}", jsonStr);
     }
 }
diff --git a/common/src/test/java/org/opensearch/ml/common/dataframe/RowTest.java b/common/src/test/java/org/opensearch/ml/common/dataframe/RowTest.java
index d5263dbcad..0fb081d105 100644
--- a/common/src/test/java/org/opensearch/ml/common/dataframe/RowTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/dataframe/RowTest.java
@@ -13,7 +13,6 @@
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -136,7 +135,7 @@ public void testToXContent() throws IOException {
         row.toXContent(builder);
 
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
 
         assertEquals("{\"values\":[{\"column_type\":\"INTEGER\",\"value\":0}]}", jsonStr);
     }
diff --git a/common/src/test/java/org/opensearch/ml/common/dataframe/ShortValueTest.java b/common/src/test/java/org/opensearch/ml/common/dataframe/ShortValueTest.java
index ad4c0f928a..2ef5d4f411 100644
--- a/common/src/test/java/org/opensearch/ml/common/dataframe/ShortValueTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/dataframe/ShortValueTest.java
@@ -6,7 +6,6 @@
 package org.opensearch.ml.common.dataframe;
 
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
 
@@ -32,7 +31,7 @@ public void testToXContent() throws IOException {
         shortValue.toXContent(builder);
 
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"column_type\":\"SHORT\",\"value\":2}", jsonStr);
     }
 }
diff --git a/common/src/test/java/org/opensearch/ml/common/dataframe/StringValueTest.java b/common/src/test/java/org/opensearch/ml/common/dataframe/StringValueTest.java
index 1c2fd613c7..0f4df02a47 100644
--- a/common/src/test/java/org/opensearch/ml/common/dataframe/StringValueTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/dataframe/StringValueTest.java
@@ -6,7 +6,6 @@
 package org.opensearch.ml.common.dataframe;
 
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -37,7 +36,7 @@ public void testToXContent() throws IOException {
         value.toXContent(builder, ToXContent.EMPTY_PARAMS);
 
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"column_type\":\"STRING\",\"value\":\"str\"}", jsonStr);
     }
 }
diff --git a/common/src/test/java/org/opensearch/ml/common/input/MLInputTest.java b/common/src/test/java/org/opensearch/ml/common/input/MLInputTest.java
index e34541d914..1ebfff99f7 100644
--- a/common/src/test/java/org/opensearch/ml/common/input/MLInputTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/input/MLInputTest.java
@@ -10,7 +10,6 @@
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.common.settings.Settings;
@@ -153,7 +152,7 @@ private void testParse(FunctionName algorithm, MLInputDataset inputDataset, Stri
         XContentBuilder builder = XContentFactory.jsonBuilder();
         input.toXContent(builder, ToXContent.EMPTY_PARAMS);
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals(expectedInputStr, jsonStr);
 
         XContentParser parser = XContentType.JSON.xContent().createParser(new NamedXContentRegistry(new SearchModule(Settings.EMPTY,
diff --git a/common/src/test/java/org/opensearch/ml/common/input/execute/anomalylocalization/AnomalyLocalizationInputTests.java b/common/src/test/java/org/opensearch/ml/common/input/execute/anomalylocalization/AnomalyLocalizationInputTests.java
index 33306a3a5c..bf1a809501 100644
--- a/common/src/test/java/org/opensearch/ml/common/input/execute/anomalylocalization/AnomalyLocalizationInputTests.java
+++ b/common/src/test/java/org/opensearch/ml/common/input/execute/anomalylocalization/AnomalyLocalizationInputTests.java
@@ -10,7 +10,6 @@
 import java.util.Optional;
 
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.core.common.io.stream.NamedWriteableAwareStreamInput;
 import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
@@ -36,7 +35,7 @@ public void testXContentFullObject() throws Exception {
                 Optional.of(QueryBuilders.matchAllQuery()));
         XContentBuilder builder = XContentFactory.jsonBuilder();
         builder = input.toXContent(builder, null);
-        String json = StringUtils.xContentBuilderToString(builder);
+        String json = builder.toString();
 
         XContentParser parser = XContentType.JSON.xContent().createParser(new NamedXContentRegistry(new SearchModule(Settings.EMPTY,
                 Collections.emptyList()).getNamedXContents()), null, json);
@@ -52,7 +51,7 @@ public void testXContentMissingAnomalyStartFilter() throws Exception {
                 "@timestamp", 0L, 10L, 1L, 2, Optional.empty(), Optional.empty());
         XContentBuilder builder = XContentFactory.jsonBuilder();
         builder = input.toXContent(builder, null);
-        String json = StringUtils.xContentBuilderToString(builder);
+        String json = builder.toString();
 
         XContentParser parser = XContentType.JSON.xContent().createParser(new NamedXContentRegistry(new SearchModule(Settings.EMPTY,
                 Collections.emptyList()).getNamedXContents()), null, json);
diff --git a/common/src/test/java/org/opensearch/ml/common/input/nlp/TextDocsMLInputTest.java b/common/src/test/java/org/opensearch/ml/common/input/nlp/TextDocsMLInputTest.java
index 52522fead7..6578cd42bd 100644
--- a/common/src/test/java/org/opensearch/ml/common/input/nlp/TextDocsMLInputTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/input/nlp/TextDocsMLInputTest.java
@@ -4,7 +4,6 @@
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.XContentType;
@@ -47,7 +46,7 @@ public void setUp() throws Exception {
     public void parseTextDocsMLInput() throws IOException {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         input.toXContent(builder, ToXContent.EMPTY_PARAMS);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         parseMLInput(jsonStr);
     }
 
diff --git a/common/src/test/java/org/opensearch/ml/common/output/MLPredictionOutputTest.java b/common/src/test/java/org/opensearch/ml/common/output/MLPredictionOutputTest.java
index c4f522ce1c..9ba54314e2 100644
--- a/common/src/test/java/org/opensearch/ml/common/output/MLPredictionOutputTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/output/MLPredictionOutputTest.java
@@ -7,7 +7,6 @@
 
 import org.junit.Before;
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.common.xcontent.XContentFactory;
@@ -47,7 +46,7 @@ public void setUp() {
     public void toXContent() throws IOException {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         output.toXContent(builder, ToXContent.EMPTY_PARAMS);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"task_id\":\"test_task_id\",\"status\":\"test_status\",\"prediction_result\":" +
                 "{\"column_metas\":[{\"name\":\"test\",\"column_type\":\"INTEGER\"}],\"rows\":[{\"values\":" +
                 "[{\"column_type\":\"INTEGER\",\"value\":1}]},{\"values\":[{\"column_type\":\"INTEGER\"," +
@@ -59,7 +58,7 @@ public void toXContent_EmptyOutput() throws IOException {
         MLPredictionOutput output = MLPredictionOutput.builder().build();
         XContentBuilder builder = XContentFactory.jsonBuilder();
         output.toXContent(builder, ToXContent.EMPTY_PARAMS);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{}", jsonStr);
     }
 
diff --git a/common/src/test/java/org/opensearch/ml/common/output/MLTrainingOutputTest.java b/common/src/test/java/org/opensearch/ml/common/output/MLTrainingOutputTest.java
index 8cd8695f13..6671da9e98 100644
--- a/common/src/test/java/org/opensearch/ml/common/output/MLTrainingOutputTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/output/MLTrainingOutputTest.java
@@ -6,7 +6,6 @@
 package org.opensearch.ml.common.output;
 
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.XContentBuilder;
@@ -22,7 +21,7 @@ public void parse_MLTrain() throws IOException {
                 .modelId("test_modelId").status("test_status").build();
         XContentBuilder builder = XContentFactory.jsonBuilder();
         output.toXContent(builder, ToXContent.EMPTY_PARAMS);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"model_id\":\"test_modelId\",\"status\":\"test_status\"}", jsonStr);
     }
 }
diff --git a/common/src/test/java/org/opensearch/ml/common/output/execute/anomalylocalization/AnomalyLocalizationOutputTests.java b/common/src/test/java/org/opensearch/ml/common/output/execute/anomalylocalization/AnomalyLocalizationOutputTests.java
index f14b9817b8..d14508ea43 100644
--- a/common/src/test/java/org/opensearch/ml/common/output/execute/anomalylocalization/AnomalyLocalizationOutputTests.java
+++ b/common/src/test/java/org/opensearch/ml/common/output/execute/anomalylocalization/AnomalyLocalizationOutputTests.java
@@ -9,7 +9,6 @@
 
 import org.junit.Before;
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.XContentType;
@@ -51,7 +50,7 @@ public void testXContent() throws Exception {
         builder.startObject();
         builder = output.toXContent(builder, null);
         builder.endObject();
-        String json = StringUtils.xContentBuilderToString(builder);
+        String json = builder.toString();
         XContentParser parser = XContentType.JSON.xContent().createParser(NamedXContentRegistry.EMPTY, null, json);
         AnomalyLocalizationOutput newOutput = AnomalyLocalizationOutput.parse(parser);
 
diff --git a/common/src/test/java/org/opensearch/ml/common/output/execute/samplecalculator/LocalSampleCalculatorOutputTest.java b/common/src/test/java/org/opensearch/ml/common/output/execute/samplecalculator/LocalSampleCalculatorOutputTest.java
index ea45e71ab5..d22b24b316 100644
--- a/common/src/test/java/org/opensearch/ml/common/output/execute/samplecalculator/LocalSampleCalculatorOutputTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/output/execute/samplecalculator/LocalSampleCalculatorOutputTest.java
@@ -7,7 +7,6 @@
 
 import org.junit.Before;
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.common.xcontent.XContentFactory;
@@ -34,7 +33,7 @@ public void toXContent() throws IOException {
         builder.startObject();
         output.toXContent(builder, ToXContent.EMPTY_PARAMS);
         builder.endObject();
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"result\":1.0}", jsonStr);
     }
 
@@ -45,7 +44,7 @@ public void toXContent_EmptyOutput() throws IOException {
         builder.startObject();
         output.toXContent(builder, ToXContent.EMPTY_PARAMS);
         builder.endObject();
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{}", jsonStr);
     }
 
diff --git a/common/src/test/java/org/opensearch/ml/common/output/sample/SampleAlgoOutputTest.java b/common/src/test/java/org/opensearch/ml/common/output/sample/SampleAlgoOutputTest.java
index 52ae46e3d2..1fd5a51176 100644
--- a/common/src/test/java/org/opensearch/ml/common/output/sample/SampleAlgoOutputTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/output/sample/SampleAlgoOutputTest.java
@@ -7,7 +7,6 @@
 
 import org.junit.Before;
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.common.xcontent.XContentFactory;
@@ -32,7 +31,7 @@ public void setUp() {
     public void toXContent() throws IOException {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         output.toXContent(builder, ToXContent.EMPTY_PARAMS);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"sample_result\":1.0}", jsonStr);
     }
 
@@ -41,7 +40,7 @@ public void toXContent_EmptyOutput() throws IOException {
         SampleAlgoOutput output = SampleAlgoOutput.builder().build();
         XContentBuilder builder = XContentFactory.jsonBuilder();
         output.toXContent(builder, ToXContent.EMPTY_PARAMS);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{}", jsonStr);
     }
 
diff --git a/common/src/test/java/org/opensearch/ml/common/transport/connector/MLConnectorGetResponseTests.java b/common/src/test/java/org/opensearch/ml/common/transport/connector/MLConnectorGetResponseTests.java
index 6b1b2362a7..040cda0ec7 100644
--- a/common/src/test/java/org/opensearch/ml/common/transport/connector/MLConnectorGetResponseTests.java
+++ b/common/src/test/java/org/opensearch/ml/common/transport/connector/MLConnectorGetResponseTests.java
@@ -16,7 +16,6 @@
 import org.junit.Before;
 import org.junit.Test;
 import org.opensearch.action.ActionResponse;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.common.io.stream.StreamOutput;
@@ -57,7 +56,7 @@ public void toXContentTest() throws IOException {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         mlConnectorGetResponse.toXContent(builder, ToXContent.EMPTY_PARAMS);
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"name\":\"test_connector_name\"," +
                 "\"version\":\"1\",\"description\":\"this is a test connector\",\"protocol\":\"http\"," +
                 "\"parameters\":{\"input\":\"test input value\"},\"credential\":{\"key\":\"test_key_value\"}," +
diff --git a/common/src/test/java/org/opensearch/ml/common/transport/connector/MLCreateConnectorInputTests.java b/common/src/test/java/org/opensearch/ml/common/transport/connector/MLCreateConnectorInputTests.java
index 57fb1748f2..4749111946 100644
--- a/common/src/test/java/org/opensearch/ml/common/transport/connector/MLCreateConnectorInputTests.java
+++ b/common/src/test/java/org/opensearch/ml/common/transport/connector/MLCreateConnectorInputTests.java
@@ -21,7 +21,6 @@
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.LoggingDeprecationHandler;
@@ -144,7 +143,7 @@ public void testToXContent_FullFields() throws Exception {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         mlCreateConnectorInput.toXContent(builder, ToXContent.EMPTY_PARAMS);
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals(expectedInputStr, jsonStr);
     }
 
@@ -153,7 +152,7 @@ public void testToXContent_NullFields() throws Exception {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         mlCreateDryRunConnectorInput.toXContent(builder, ToXContent.EMPTY_PARAMS);
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{}", jsonStr);
     }
 
diff --git a/common/src/test/java/org/opensearch/ml/common/transport/deploy/MLDeployModelNodesResponseTest.java b/common/src/test/java/org/opensearch/ml/common/transport/deploy/MLDeployModelNodesResponseTest.java
index 3856add001..f3a146aa06 100644
--- a/common/src/test/java/org/opensearch/ml/common/transport/deploy/MLDeployModelNodesResponseTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/transport/deploy/MLDeployModelNodesResponseTest.java
@@ -9,7 +9,6 @@
 import org.opensearch.action.FailedNodeException;
 import org.opensearch.cluster.ClusterName;
 import org.opensearch.cluster.node.DiscoveryNode;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.common.xcontent.XContentFactory;
@@ -77,7 +76,7 @@ public void testToXContent() throws IOException {
         MLDeployModelNodesResponse response = new MLDeployModelNodesResponse(clusterName, nodes, failures);
         XContentBuilder builder = XContentFactory.jsonBuilder();
         response.toXContent(builder, ToXContent.EMPTY_PARAMS);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals(
                 "{\"foo1\":{\"stats\":{\"modelName:version1\":\"response\"}},\"foo2\":{\"stats\":{\"modelName:version2\":\"response\"}}}",
                 jsonStr
diff --git a/common/src/test/java/org/opensearch/ml/common/transport/deploy/MLDeployModelResponseTest.java b/common/src/test/java/org/opensearch/ml/common/transport/deploy/MLDeployModelResponseTest.java
index c59064af6e..e80f3aefd6 100644
--- a/common/src/test/java/org/opensearch/ml/common/transport/deploy/MLDeployModelResponseTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/transport/deploy/MLDeployModelResponseTest.java
@@ -2,7 +2,6 @@
 
 import org.junit.Before;
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.ToXContent;
@@ -45,7 +44,7 @@ public void testToXContent() throws IOException {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         response.toXContent(builder, ToXContent.EMPTY_PARAMS);
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         // Verify the results
         assertEquals("{\"task_id\":\"test_id\"," +
                 "\"status\":\"test\"}", jsonStr);
diff --git a/common/src/test/java/org/opensearch/ml/common/transport/execute/MLExecuteTaskResponseTest.java b/common/src/test/java/org/opensearch/ml/common/transport/execute/MLExecuteTaskResponseTest.java
index 5a1eb59caa..b1ec905e44 100644
--- a/common/src/test/java/org/opensearch/ml/common/transport/execute/MLExecuteTaskResponseTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/transport/execute/MLExecuteTaskResponseTest.java
@@ -1,7 +1,6 @@
 package org.opensearch.ml.common.transport.execute;
 
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.ToXContent;
@@ -89,7 +88,7 @@ public void toXContentTest() throws IOException {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         response.toXContent(builder, ToXContent.EMPTY_PARAMS);
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"function_name\":\"METRICS_CORRELATION\"," +
                 "\"output\":{\"inference_results\":[{" +
                 "\"event_window\":[4.0,5.0,6.0]," +
diff --git a/common/src/test/java/org/opensearch/ml/common/transport/forward/MLForwardResponseTest.java b/common/src/test/java/org/opensearch/ml/common/transport/forward/MLForwardResponseTest.java
index f6779109ea..941e40dfa1 100644
--- a/common/src/test/java/org/opensearch/ml/common/transport/forward/MLForwardResponseTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/transport/forward/MLForwardResponseTest.java
@@ -5,7 +5,6 @@
 import org.junit.runner.RunWith;
 import org.mockito.junit.MockitoJUnitRunner;
 import org.opensearch.action.ActionResponse;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.common.xcontent.XContentFactory;
@@ -62,7 +61,7 @@ public void testToXContent() throws IOException {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         response.toXContent(builder, ToXContent.EMPTY_PARAMS);
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         // Verify the results
         assertEquals("{\"result\":{\"task_id\":\"taskId\",\"status\":\"Success\",\"prediction_result\":{\"column_metas\":[{\"name\":\"key1\",\"column_type\":\"DOUBLE\"}],\"rows\":[{\"values\":[{\"column_type\":\"DOUBLE\",\"value\":2.0}]}]}}}", jsonStr);
     }
diff --git a/common/src/test/java/org/opensearch/ml/common/transport/model/MLModelGetResponseTest.java b/common/src/test/java/org/opensearch/ml/common/transport/model/MLModelGetResponseTest.java
index 14a4d88ea8..f91c94d1c2 100644
--- a/common/src/test/java/org/opensearch/ml/common/transport/model/MLModelGetResponseTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/transport/model/MLModelGetResponseTest.java
@@ -16,7 +16,6 @@
 import org.junit.Before;
 import org.junit.Test;
 import org.opensearch.action.ActionResponse;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.commons.authuser.User;
@@ -63,7 +62,7 @@ public void toXContentTest() throws IOException {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         mlModelGetResponse.toXContent(builder, ToXContent.EMPTY_PARAMS);
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"name\":\"model\"," +
                 "\"algorithm\":\"KMEANS\"," +
                 "\"model_version\":\"1.0.0\"," +
diff --git a/common/src/test/java/org/opensearch/ml/common/transport/prediction/MLPredictionTaskResponseTest.java b/common/src/test/java/org/opensearch/ml/common/transport/prediction/MLPredictionTaskResponseTest.java
index ade18f6ca7..27ac14c962 100644
--- a/common/src/test/java/org/opensearch/ml/common/transport/prediction/MLPredictionTaskResponseTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/transport/prediction/MLPredictionTaskResponseTest.java
@@ -7,7 +7,6 @@
 
 import org.junit.Test;
 import org.opensearch.action.ActionResponse;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.core.common.io.stream.StreamOutput;
 import org.opensearch.common.xcontent.XContentFactory;
@@ -122,7 +121,7 @@ public void toXContentTest() throws IOException {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         response.toXContent(builder, ToXContent.EMPTY_PARAMS);
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"task_id\":\"b5009b99-268f-476d-a676-379a30f82457\"," +
              "\"status\":\"Success\"," +
              "\"prediction_result\":{" +
diff --git a/common/src/test/java/org/opensearch/ml/common/transport/register/MLRegisterModelInputTest.java b/common/src/test/java/org/opensearch/ml/common/transport/register/MLRegisterModelInputTest.java
index 456e528ded..c28d4ccb1e 100644
--- a/common/src/test/java/org/opensearch/ml/common/transport/register/MLRegisterModelInputTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/transport/register/MLRegisterModelInputTest.java
@@ -7,7 +7,6 @@
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
 import org.mockito.junit.MockitoJUnitRunner;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.common.settings.Settings;
@@ -148,7 +147,7 @@ public void testToXContent() throws Exception {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         input.toXContent(builder, ToXContent.EMPTY_PARAMS);
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals(expectedInputStr, jsonStr);
     }
 
@@ -164,7 +163,7 @@ public void testToXContent_Incomplete() throws Exception {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         input.toXContent(builder, ToXContent.EMPTY_PARAMS);
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals(expectedIncompleteInputStr, jsonStr);
     }
 
diff --git a/common/src/test/java/org/opensearch/ml/common/transport/register/MLRegisterModelResponseTest.java b/common/src/test/java/org/opensearch/ml/common/transport/register/MLRegisterModelResponseTest.java
index 4670905e0e..555c9163e5 100644
--- a/common/src/test/java/org/opensearch/ml/common/transport/register/MLRegisterModelResponseTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/transport/register/MLRegisterModelResponseTest.java
@@ -2,7 +2,6 @@
 
 import org.junit.Before;
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.ToXContent;
@@ -45,7 +44,7 @@ public void testToXContent() throws IOException {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         response.toXContent(builder, ToXContent.EMPTY_PARAMS);
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         // Verify the results
         assertEquals("{\"task_id\":\"test_id\"," +
                 "\"status\":\"test\"}", jsonStr);
diff --git a/common/src/test/java/org/opensearch/ml/common/transport/sync/MLSyncUpResponseTest.java b/common/src/test/java/org/opensearch/ml/common/transport/sync/MLSyncUpResponseTest.java
index 49ce35f12b..c183841431 100644
--- a/common/src/test/java/org/opensearch/ml/common/transport/sync/MLSyncUpResponseTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/transport/sync/MLSyncUpResponseTest.java
@@ -4,7 +4,6 @@
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.junit.MockitoJUnitRunner;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.ToXContent;
@@ -44,7 +43,7 @@ public void testToXContent() throws IOException {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         response.toXContent(builder, ToXContent.EMPTY_PARAMS);
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         // Verify the results
         assertEquals("{\"status\":\"test\"}", jsonStr);
     }
diff --git a/common/src/test/java/org/opensearch/ml/common/transport/task/MLTaskGetResponseTest.java b/common/src/test/java/org/opensearch/ml/common/transport/task/MLTaskGetResponseTest.java
index 0ec850ca6b..8eeff0916e 100644
--- a/common/src/test/java/org/opensearch/ml/common/transport/task/MLTaskGetResponseTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/transport/task/MLTaskGetResponseTest.java
@@ -2,7 +2,6 @@
 
 import org.junit.Before;
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.commons.authuser.User;
@@ -71,7 +70,7 @@ public void toXContentTest() throws IOException {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         mlTaskGetResponse.toXContent(builder, ToXContent.EMPTY_PARAMS);
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals("{\"task_id\":\"id\"," +
                 "\"model_id\":\"model id\"," +
                 "\"task_type\":\"EXECUTION\"," +
diff --git a/common/src/test/java/org/opensearch/ml/common/transport/undeploy/MLUndeployModelInputTest.java b/common/src/test/java/org/opensearch/ml/common/transport/undeploy/MLUndeployModelInputTest.java
index ecd8bc5d75..44e820dc37 100644
--- a/common/src/test/java/org/opensearch/ml/common/transport/undeploy/MLUndeployModelInputTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/transport/undeploy/MLUndeployModelInputTest.java
@@ -2,7 +2,6 @@
 
 import org.junit.Before;
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.common.settings.Settings;
@@ -38,7 +37,7 @@ public void testToXContent() throws Exception {
         XContentBuilder builder = XContentFactory.jsonBuilder();
         input.toXContent(builder, ToXContent.EMPTY_PARAMS);
         assertNotNull(builder);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals(expectedInputStr, jsonStr);
     }
 
diff --git a/common/src/test/java/org/opensearch/ml/common/transport/undeploy/MLUndeployModelNodesResponseTest.java b/common/src/test/java/org/opensearch/ml/common/transport/undeploy/MLUndeployModelNodesResponseTest.java
index 3c3ab462b9..e27b53dbb2 100644
--- a/common/src/test/java/org/opensearch/ml/common/transport/undeploy/MLUndeployModelNodesResponseTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/transport/undeploy/MLUndeployModelNodesResponseTest.java
@@ -9,7 +9,6 @@
 import org.opensearch.action.FailedNodeException;
 import org.opensearch.cluster.ClusterName;
 import org.opensearch.cluster.node.DiscoveryNode;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.common.xcontent.XContentFactory;
@@ -90,7 +89,7 @@ public void testToXContent() throws IOException {
         MLUndeployModelNodesResponse response = new MLUndeployModelNodesResponse(clusterName, nodes, failures);
         XContentBuilder builder = XContentFactory.jsonBuilder();
         response.toXContent(builder, ToXContent.EMPTY_PARAMS);
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         assertEquals(
                 "{\"foo1\":{\"stats\":{\"modelId1\":\"response\"}},\"foo2\":{\"stats\":{\"modelId2\":\"response\"}}}",
                 jsonStr
diff --git a/common/src/test/java/org/opensearch/ml/common/transport/upload_chunk/MLUploadModelChunkInputTest.java b/common/src/test/java/org/opensearch/ml/common/transport/upload_chunk/MLUploadModelChunkInputTest.java
index 90b70617d7..cafec77356 100644
--- a/common/src/test/java/org/opensearch/ml/common/transport/upload_chunk/MLUploadModelChunkInputTest.java
+++ b/common/src/test/java/org/opensearch/ml/common/transport/upload_chunk/MLUploadModelChunkInputTest.java
@@ -15,7 +15,6 @@
 
 import org.junit.Before;
 import org.junit.Test;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.core.common.io.stream.StreamInput;
 import org.opensearch.common.settings.Settings;
@@ -90,7 +89,7 @@ public void testToXContent() throws IOException {
 	public void testMLUploadModelChunkInputParser() throws IOException {
 		XContentBuilder builder = XContentFactory.jsonBuilder();
 		builder = mlUploadModelChunkInput.toXContent(builder, null);
-		String json = StringUtils.xContentBuilderToString(builder);
+		String json = builder.toString();
 		XContentParser parser = XContentType.JSON.xContent().createParser(new NamedXContentRegistry(
 				new SearchModule(Settings.EMPTY, Collections.emptyList()).getNamedXContents()), null, json);
 		parser.nextToken();
diff --git a/plugin/src/main/java/org/opensearch/ml/action/connector/TransportCreateConnectorAction.java b/plugin/src/main/java/org/opensearch/ml/action/connector/TransportCreateConnectorAction.java
index 08e1ff848d..971a0c5db3 100644
--- a/plugin/src/main/java/org/opensearch/ml/action/connector/TransportCreateConnectorAction.java
+++ b/plugin/src/main/java/org/opensearch/ml/action/connector/TransportCreateConnectorAction.java
@@ -22,11 +22,11 @@
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.inject.Inject;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.core.common.util.CollectionUtils;
 import org.opensearch.common.util.concurrent.ThreadContext;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.commons.authuser.User;
+import org.opensearch.core.common.util.CollectionUtils;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.ml.common.AccessMode;
diff --git a/plugin/src/main/java/org/opensearch/ml/action/handler/MLSearchHandler.java b/plugin/src/main/java/org/opensearch/ml/action/handler/MLSearchHandler.java
index 812ba61fbe..ab3d28d3d7 100644
--- a/plugin/src/main/java/org/opensearch/ml/action/handler/MLSearchHandler.java
+++ b/plugin/src/main/java/org/opensearch/ml/action/handler/MLSearchHandler.java
@@ -21,9 +21,9 @@
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.client.Client;
 import org.opensearch.cluster.service.ClusterService;
-import org.opensearch.core.common.util.CollectionUtils;
 import org.opensearch.common.util.concurrent.ThreadContext;
 import org.opensearch.commons.authuser.User;
+import org.opensearch.core.common.util.CollectionUtils;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.index.IndexNotFoundException;
@@ -44,7 +44,6 @@
 import org.opensearch.search.builder.SearchSourceBuilder;
 import org.opensearch.search.fetch.subphase.FetchSourceContext;
 
-
 import lombok.extern.log4j.Log4j2;
 
 /**
diff --git a/plugin/src/main/java/org/opensearch/ml/action/model_group/TransportUpdateModelGroupAction.java b/plugin/src/main/java/org/opensearch/ml/action/model_group/TransportUpdateModelGroupAction.java
index b1e52abf46..8ba6173739 100644
--- a/plugin/src/main/java/org/opensearch/ml/action/model_group/TransportUpdateModelGroupAction.java
+++ b/plugin/src/main/java/org/opensearch/ml/action/model_group/TransportUpdateModelGroupAction.java
@@ -25,9 +25,9 @@
 import org.opensearch.client.Client;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.inject.Inject;
-import org.opensearch.core.common.util.CollectionUtils;
 import org.opensearch.common.util.concurrent.ThreadContext;
 import org.opensearch.commons.authuser.User;
+import org.opensearch.core.common.util.CollectionUtils;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.core.xcontent.XContentParser;
diff --git a/plugin/src/main/java/org/opensearch/ml/helper/ModelAccessControlHelper.java b/plugin/src/main/java/org/opensearch/ml/helper/ModelAccessControlHelper.java
index a5f183215f..4a85f511cd 100644
--- a/plugin/src/main/java/org/opensearch/ml/helper/ModelAccessControlHelper.java
+++ b/plugin/src/main/java/org/opensearch/ml/helper/ModelAccessControlHelper.java
@@ -21,9 +21,9 @@
 import org.opensearch.client.Client;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.core.common.util.CollectionUtils;
 import org.opensearch.common.util.concurrent.ThreadContext;
 import org.opensearch.commons.authuser.User;
+import org.opensearch.core.common.util.CollectionUtils;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.core.xcontent.XContentParser;
 import org.opensearch.index.IndexNotFoundException;
diff --git a/plugin/src/main/java/org/opensearch/ml/model/MLModelGroupManager.java b/plugin/src/main/java/org/opensearch/ml/model/MLModelGroupManager.java
index 4a34ab30e5..26aeadc820 100644
--- a/plugin/src/main/java/org/opensearch/ml/model/MLModelGroupManager.java
+++ b/plugin/src/main/java/org/opensearch/ml/model/MLModelGroupManager.java
@@ -19,10 +19,10 @@
 import org.opensearch.client.Client;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.inject.Inject;
-import org.opensearch.core.common.util.CollectionUtils;
 import org.opensearch.common.util.concurrent.ThreadContext;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.commons.authuser.User;
+import org.opensearch.core.common.util.CollectionUtils;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.IndexNotFoundException;
diff --git a/plugin/src/main/java/org/opensearch/ml/utils/MLExceptionUtils.java b/plugin/src/main/java/org/opensearch/ml/utils/MLExceptionUtils.java
index 45529a3ce6..e59e2ee0fe 100644
--- a/plugin/src/main/java/org/opensearch/ml/utils/MLExceptionUtils.java
+++ b/plugin/src/main/java/org/opensearch/ml/utils/MLExceptionUtils.java
@@ -10,7 +10,6 @@
 
 import org.apache.commons.lang3.exception.ExceptionUtils;
 import org.apache.logging.log4j.Logger;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.ml.common.exception.MLLimitExceededException;
@@ -39,7 +38,7 @@ public static String toJsonString(Map<String, String> nodeErrors) throws IOExcep
             builder.field(entry.getKey(), entry.getValue());
         }
         builder.endObject();
-        return StringUtils.xContentBuilderToString(builder);
+        return builder.toString();
     }
 
     public static void logException(String errorMessage, Exception e, Logger log) {
diff --git a/plugin/src/test/java/org/opensearch/ml/action/deploy/TransportDeployModelOnNodeActionTests.java b/plugin/src/test/java/org/opensearch/ml/action/deploy/TransportDeployModelOnNodeActionTests.java
index d4038ad8be..2f283cf703 100644
--- a/plugin/src/test/java/org/opensearch/ml/action/deploy/TransportDeployModelOnNodeActionTests.java
+++ b/plugin/src/test/java/org/opensearch/ml/action/deploy/TransportDeployModelOnNodeActionTests.java
@@ -47,8 +47,8 @@
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.common.util.concurrent.ThreadContext;
+import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.ml.breaker.MLCircuitBreakerService;
 import org.opensearch.ml.common.FunctionName;
diff --git a/plugin/src/test/java/org/opensearch/ml/action/undeploy/TransportUndeployModelActionTests.java b/plugin/src/test/java/org/opensearch/ml/action/undeploy/TransportUndeployModelActionTests.java
index 125057fbf7..8de5cf5ec8 100644
--- a/plugin/src/test/java/org/opensearch/ml/action/undeploy/TransportUndeployModelActionTests.java
+++ b/plugin/src/test/java/org/opensearch/ml/action/undeploy/TransportUndeployModelActionTests.java
@@ -39,8 +39,8 @@
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.io.stream.BytesStreamOutput;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.common.util.concurrent.ThreadContext;
+import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.ml.cluster.DiscoveryNodeHelper;
 import org.opensearch.ml.common.MLModel;
diff --git a/plugin/src/test/java/org/opensearch/ml/autoredeploy/MLModelAutoReDeployerTests.java b/plugin/src/test/java/org/opensearch/ml/autoredeploy/MLModelAutoReDeployerTests.java
index 669fcc1a67..ee9d1df5db 100644
--- a/plugin/src/test/java/org/opensearch/ml/autoredeploy/MLModelAutoReDeployerTests.java
+++ b/plugin/src/test/java/org/opensearch/ml/autoredeploy/MLModelAutoReDeployerTests.java
@@ -38,9 +38,9 @@
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.common.bytes.BytesReference;
+import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.ml.common.MLModel;
diff --git a/plugin/src/test/java/org/opensearch/ml/cluster/MLSyncUpCronTests.java b/plugin/src/test/java/org/opensearch/ml/cluster/MLSyncUpCronTests.java
index 3f408f3a4d..00b917b94d 100644
--- a/plugin/src/test/java/org/opensearch/ml/cluster/MLSyncUpCronTests.java
+++ b/plugin/src/test/java/org/opensearch/ml/cluster/MLSyncUpCronTests.java
@@ -57,10 +57,10 @@
 import org.opensearch.cluster.node.DiscoveryNodes;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.common.util.concurrent.ThreadContext;
 import org.opensearch.commons.ConfigConstants;
 import org.opensearch.core.common.bytes.BytesReference;
+import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.ml.common.MLModel;
 import org.opensearch.ml.common.model.MLModelState;
diff --git a/plugin/src/test/java/org/opensearch/ml/rest/RestMLProfileActionTests.java b/plugin/src/test/java/org/opensearch/ml/rest/RestMLProfileActionTests.java
index ef73fe7df9..2a6ce1f9f2 100644
--- a/plugin/src/test/java/org/opensearch/ml/rest/RestMLProfileActionTests.java
+++ b/plugin/src/test/java/org/opensearch/ml/rest/RestMLProfileActionTests.java
@@ -40,10 +40,10 @@
 import org.opensearch.cluster.node.DiscoveryNodeRole;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.commons.authuser.User;
 import org.opensearch.core.common.Strings;
+import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.ml.action.profile.MLProfileAction;
 import org.opensearch.ml.action.profile.MLProfileNodeResponse;
diff --git a/plugin/src/test/java/org/opensearch/ml/rest/RestMLStatsActionTests.java b/plugin/src/test/java/org/opensearch/ml/rest/RestMLStatsActionTests.java
index 50d3c5bbfb..099b09d60d 100644
--- a/plugin/src/test/java/org/opensearch/ml/rest/RestMLStatsActionTests.java
+++ b/plugin/src/test/java/org/opensearch/ml/rest/RestMLStatsActionTests.java
@@ -45,9 +45,9 @@
 import org.opensearch.cluster.node.DiscoveryNodeRole;
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.common.bytes.BytesReference;
+import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.ml.action.stats.MLStatsNodeResponse;
 import org.opensearch.ml.action.stats.MLStatsNodesAction;
diff --git a/plugin/src/test/java/org/opensearch/ml/utils/IntegTestUtils.java b/plugin/src/test/java/org/opensearch/ml/utils/IntegTestUtils.java
index 76ef30380e..16036dd438 100644
--- a/plugin/src/test/java/org/opensearch/ml/utils/IntegTestUtils.java
+++ b/plugin/src/test/java/org/opensearch/ml/utils/IntegTestUtils.java
@@ -22,7 +22,6 @@
 import org.opensearch.action.search.SearchRequest;
 import org.opensearch.action.search.SearchResponse;
 import org.opensearch.action.support.WriteRequest;
-import org.opensearch.ml.common.utils.StringUtils;
 import org.opensearch.common.unit.TimeValue;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.XContentType;
@@ -194,7 +193,7 @@ public static void predictAndVerifyResult(String taskId, MLInputDataset inputDat
         MLPredictionOutput mlPredictionOutput = (MLPredictionOutput) predictionResponse.getOutput();
         mlPredictionOutput.getPredictionResult().toXContent(builder, ToXContent.EMPTY_PARAMS);
         builder.endObject();
-        String jsonStr = StringUtils.xContentBuilderToString(builder);
+        String jsonStr = builder.toString();
         String expectedStr1 = "{\"column_metas\":[{\"name\":\"ClusterID\",\"column_type\":\"INTEGER\"}],"
             + "\"rows\":[{\"values\":[{\"column_type\":\"INTEGER\",\"value\":0}]}]}";
         String expectedStr2 = "{\"column_metas\":[{\"name\":\"ClusterID\",\"column_type\":\"INTEGER\"}],"
diff --git a/plugin/src/test/java/org/opensearch/ml/utils/TestHelper.java b/plugin/src/test/java/org/opensearch/ml/utils/TestHelper.java
index 7f7ac4d7f7..23db025a04 100644
--- a/plugin/src/test/java/org/opensearch/ml/utils/TestHelper.java
+++ b/plugin/src/test/java/org/opensearch/ml/utils/TestHelper.java
@@ -53,12 +53,12 @@
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
-import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.common.xcontent.LoggingDeprecationHandler;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.XContentType;
 import org.opensearch.core.common.bytes.BytesArray;
 import org.opensearch.core.common.bytes.BytesReference;
+import org.opensearch.core.common.transport.TransportAddress;
 import org.opensearch.core.rest.RestStatus;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.core.xcontent.ToXContent;