diff --git a/common/network-shuffle/src/test/java/org/apache/spark/network/shuffle/ExternalShuffleBlockResolverSuite.java b/common/network-shuffle/src/test/java/org/apache/spark/network/shuffle/ExternalShuffleBlockResolverSuite.java
index 311827dbed4c5..3e068d4573688 100644
--- a/common/network-shuffle/src/test/java/org/apache/spark/network/shuffle/ExternalShuffleBlockResolverSuite.java
+++ b/common/network-shuffle/src/test/java/org/apache/spark/network/shuffle/ExternalShuffleBlockResolverSuite.java
@@ -19,15 +19,14 @@
 
 import java.io.IOException;
 import java.io.InputStream;
-import java.io.InputStreamReader;
 import java.nio.charset.StandardCharsets;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.google.common.io.CharStreams;
 import org.apache.spark.network.shuffle.protocol.ExecutorShuffleInfo;
 import org.apache.spark.network.util.MapConfigProvider;
 import org.apache.spark.network.util.TransportConf;
 import org.apache.spark.network.shuffle.ExternalShuffleBlockResolver.AppExecId;
+import org.apache.spark.util.SparkStreamUtils$;
 import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
@@ -83,23 +82,17 @@ public void testSortShuffleBlocks() throws IOException {
 
     try (InputStream block0Stream = resolver.getBlockData(
         "app0", "exec0", 0, 0, 0).createInputStream()) {
-      String block0 =
-        CharStreams.toString(new InputStreamReader(block0Stream, StandardCharsets.UTF_8));
-      assertEquals(sortBlock0, block0);
+      assertEquals(sortBlock0, SparkStreamUtils$.MODULE$.toString(block0Stream));
     }
 
     try (InputStream block1Stream = resolver.getBlockData(
         "app0", "exec0", 0, 0, 1).createInputStream()) {
-      String block1 =
-        CharStreams.toString(new InputStreamReader(block1Stream, StandardCharsets.UTF_8));
-      assertEquals(sortBlock1, block1);
+      assertEquals(sortBlock1, SparkStreamUtils$.MODULE$.toString(block1Stream));
     }
 
     try (InputStream blocksStream = resolver.getContinuousBlocksData(
         "app0", "exec0", 0, 0, 0, 2).createInputStream()) {
-      String blocks =
-        CharStreams.toString(new InputStreamReader(blocksStream, StandardCharsets.UTF_8));
-      assertEquals(sortBlock0 + sortBlock1, blocks);
+      assertEquals(sortBlock0 + sortBlock1, SparkStreamUtils$.MODULE$.toString(blocksStream));
     }
   }
 
diff --git a/core/src/test/scala/org/apache/spark/deploy/ExternalShuffleServiceDbSuite.scala b/core/src/test/scala/org/apache/spark/deploy/ExternalShuffleServiceDbSuite.scala
index 921175bd41038..224f47f1d89c7 100644
--- a/core/src/test/scala/org/apache/spark/deploy/ExternalShuffleServiceDbSuite.scala
+++ b/core/src/test/scala/org/apache/spark/deploy/ExternalShuffleServiceDbSuite.scala
@@ -17,11 +17,8 @@
 
 package org.apache.spark.deploy
 
-import java.io._
 import java.nio.charset.StandardCharsets
 
-import com.google.common.io.CharStreams
-
 import org.apache.spark.{SecurityManager, SparkConf, SparkFunSuite}
 import org.apache.spark.internal.config._
 import org.apache.spark.network.shuffle.{ExternalBlockHandler, ExternalShuffleBlockResolver}
@@ -110,7 +107,7 @@ abstract class ExternalShuffleServiceDbSuite extends SparkFunSuite {
       blockResolver = blockHandler.getBlockResolver
 
       val block0Stream = blockResolver.getBlockData("app0", "exec0", 0, 0, 0).createInputStream
-      val block0 = CharStreams.toString(new InputStreamReader(block0Stream, StandardCharsets.UTF_8))
+      val block0 = Utils.toString(block0Stream)
       block0Stream.close()
       assert(sortBlock0 == block0)
       // pass
diff --git a/core/src/test/scala/org/apache/spark/network/netty/NettyBlockTransferSecuritySuite.scala b/core/src/test/scala/org/apache/spark/network/netty/NettyBlockTransferSecuritySuite.scala
index 124c089b47108..2733800727c0f 100644
--- a/core/src/test/scala/org/apache/spark/network/netty/NettyBlockTransferSecuritySuite.scala
+++ b/core/src/test/scala/org/apache/spark/network/netty/NettyBlockTransferSecuritySuite.scala
@@ -17,7 +17,6 @@
 
 package org.apache.spark.network.netty
 
-import java.io.InputStreamReader
 import java.nio._
 import java.nio.charset.StandardCharsets
 import java.util.concurrent.TimeUnit
@@ -26,7 +25,6 @@ import scala.concurrent.Promise
 import scala.concurrent.duration._
 import scala.util.{Failure, Success, Try}
 
-import com.google.common.io.CharStreams
 import org.mockito.Mockito._
 import org.scalatest.matchers.must.Matchers
 import org.scalatest.matchers.should.Matchers._
@@ -40,7 +38,7 @@ import org.apache.spark.network.buffer.{ManagedBuffer, NioManagedBuffer}
 import org.apache.spark.network.shuffle.BlockFetchingListener
 import org.apache.spark.serializer.{JavaSerializer, SerializerManager}
 import org.apache.spark.storage.{BlockId, ShuffleBlockId}
-import org.apache.spark.util.{SslTestUtils, ThreadUtils}
+import org.apache.spark.util.{SslTestUtils, ThreadUtils, Utils}
 
 class NettyBlockTransferSecuritySuite extends SparkFunSuite with MockitoSugar with Matchers {
 
@@ -150,9 +148,7 @@ class NettyBlockTransferSecuritySuite extends SparkFunSuite with MockitoSugar wi
 
     val result = fetchBlock(exec0, exec1, "1", blockId) match {
       case Success(buf) =>
-        val actualString = CharStreams.toString(
-          new InputStreamReader(buf.createInputStream(), StandardCharsets.UTF_8))
-        actualString should equal(blockString)
+        Utils.toString(buf.createInputStream()) should equal(blockString)
         buf.release()
         Success(())
       case Failure(t) =>
diff --git a/dev/checkstyle.xml b/dev/checkstyle.xml
index 7d34afc99345c..f9f08ed124fc7 100644
--- a/dev/checkstyle.xml
+++ b/dev/checkstyle.xml
@@ -229,6 +229,10 @@
             <property name="format" value="FileUtils\.deleteQuietly"/>
             <property name="message" value="Use deleteQuietly of JavaUtils/SparkFileUtils/Utils instead." />
         </module>
+        <module name="RegexpSinglelineJava">
+            <property name="format" value="CharStreams\.toString"/>
+            <property name="message" value="Use toString of SparkStreamUtils or Utils instead." />
+        </module>
         <!-- support structured logging -->
         <module name="RegexpSinglelineJava">
             <property name="format" value="org\.slf4j\.(Logger|LoggerFactory)" />
diff --git a/scalastyle-config.xml b/scalastyle-config.xml
index 75794f0bbc1a5..abb771a78d37e 100644
--- a/scalastyle-config.xml
+++ b/scalastyle-config.xml
@@ -722,6 +722,11 @@ This file is divided into 3 sections:
     <customMessage>Use toString of SparkStreamUtils or Utils instead.</customMessage>
   </check>
 
+  <check customId="charstreamstostring" level="error" class="org.scalastyle.file.RegexChecker" enabled="true">
+    <parameters><parameter name="regex">\bCharStreams\.toString\b</parameter></parameters>
+    <customMessage>Use toString of SparkStreamUtils or Utils instead.</customMessage>
+  </check>
+
   <check customId="ioutilswrite" level="error" class="org.scalastyle.file.RegexChecker" enabled="true">
     <parameters><parameter name="regex">\bIOUtils\.write\b</parameter></parameters>
     <customMessage>Use Java `write` instead.</customMessage>