[SPARK-18076][CORE][SQL] Fix default Locale used in DateFormat, NumberFormat to Locale.US

## What changes were proposed in this pull request?

Fix `Locale.US` for all usages of `DateFormat`, `NumberFormat`
## How was this patch tested?

Existing tests.

Author: Sean Owen <sowen@cloudera.com>

Closes #15610 from srowen/SPARK-18076.

1 files changed, 5 insertions, 6 deletions

diff --git a/mesos/src/main/scala/org/apache/spark/deploy/rest/mesos/MesosRestServer.scala b/mesos/src/main/scala/org/apache/spark/deploy/rest/mesos/MesosRestServer.scala
index 3b96488a12..ff60b88c6d 100644
--- a/mesos/src/main/scala/org/apache/spark/deploy/rest/mesos/MesosRestServer.scala
+++ b/mesos/src/main/scala/org/apache/spark/deploy/rest/mesos/MesosRestServer.scala
@@ -19,7 +19,7 @@ package org.apache.spark.deploy.rest.mesos
 
 import java.io.File
 import java.text.SimpleDateFormat
-import java.util.Date
+import java.util.{Date, Locale}
 import java.util.concurrent.atomic.AtomicLong
 import javax.servlet.http.HttpServletResponse
 
@@ -62,11 +62,10 @@ private[mesos] class MesosSubmitRequestServlet(
   private val DEFAULT_CORES = 1.0
 
   private val nextDriverNumber = new AtomicLong(0)
-  private def createDateFormat = new SimpleDateFormat("yyyyMMddHHmmss")  // For application IDs
-  private def newDriverId(submitDate: Date): String = {
-    "driver-%s-%04d".format(
-      createDateFormat.format(submitDate), nextDriverNumber.incrementAndGet())
-  }
+  // For application IDs
+  private def createDateFormat = new SimpleDateFormat("yyyyMMddHHmmss", Locale.US)
+  private def newDriverId(submitDate: Date): String =
+    f"driver-${createDateFormat.format(submitDate)}-${nextDriverNumber.incrementAndGet()}%04d"
 
   /**
    * Build a driver description from the fields specified in the submit request.