fix compile errors

resource-managers/kubernetes/core/src/main/scala/org/apache/spark/deploy/k8s/SparkKubernetesDiagnosticsSetter.scala

@@ -18,6 +18,8 @@ package org.apache.spark.deploy.k8s
 
 import io.fabric8.kubernetes.api.model.{Pod, PodBuilder}
 import io.fabric8.kubernetes.client.KubernetesClient
+import org.apache.hadoop.util.StringUtils
+
 import org.apache.spark.SparkConf
 import org.apache.spark.deploy.SparkDiagnosticsSetter
 import org.apache.spark.deploy.k8s.Config._
@@ -59,8 +61,7 @@ private[spark] class SparkKubernetesDiagnosticsSetter(
   override def setDiagnostics(throwable: Throwable, conf: SparkConf): Unit = {
     require(conf.get(KUBERNETES_DRIVER_POD_NAME).isDefined,
       "Driver pod name must be set in order to set diagnostics on the driver pod.")
-    val diagnostics = SparkStringUtils.abbreviate(
-      org.apache.hadoop.util.StringUtils.stringifyException(throwable),
+    val diagnostics = SparkStringUtils.abbreviate(StringUtils.stringifyException(throwable),
       KUBERNETES_DIAGNOSTICS_MESSAGE_LIMIT_BYTES)
     Utils.tryWithResource(clientProvider.create(conf)) { client =>
       conf.get(KUBERNETES_DRIVER_POD_NAME).foreach { podName =>

resource-managers/kubernetes/core/src/test/scala/org/apache/spark/deploy/k8s/SparkKubernetesDiagnosticsSetterSuite.scala

@@ -21,6 +21,7 @@ import java.util.function.UnaryOperator
 import io.fabric8.kubernetes.api.model.Pod
 import io.fabric8.kubernetes.client.KubernetesClient
 import io.fabric8.kubernetes.client.dsl.PodResource
+import org.apache.hadoop.util.StringUtils
 import org.mockito.{ArgumentCaptor, Mock, MockitoAnnotations}
 import org.mockito.ArgumentMatchers.any
 import org.mockito.Mockito._
@@ -75,12 +76,12 @@ class SparkKubernetesDiagnosticsSetterSuite extends SparkFunSuite
       .set(KUBERNETES_NAMESPACE, namespace)
 
     assertThrows[IllegalArgumentException] {
-      setter.setDiagnostics("diag", conf)
+      setter.setDiagnostics(new Throwable("diag"), conf)
     }
   }
 
   test("setDiagnostics should patch pod with diagnostics annotation") {
-    val diagnostics = "Fake diagnostics stack trace"
+    val diagnostics = new Throwable("Fake diagnostics stack trace")
     val conf = new SparkConf()
       .set(KUBERNETES_DRIVER_MASTER_URL, k8sClusterManagerUrl)
       .set(KUBERNETES_NAMESPACE, namespace)
@@ -96,6 +97,7 @@ class SparkKubernetesDiagnosticsSetterSuite extends SparkFunSuite
     val initialPod = SparkPod.initialPod().pod
     val editedPod = fn.apply(initialPod)
 
-    assert(editedPod.getMetadata.getAnnotations.get(DIAGNOSTICS_ANNOTATION) == diagnostics)
+    assert(editedPod.getMetadata.getAnnotations.get(DIAGNOSTICS_ANNOTATION)
+      == StringUtils.stringifyException(diagnostics))
   }
 }