[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, 3 deletions

diff --git a/streaming/src/main/scala/org/apache/spark/streaming/ui/UIUtils.scala b/streaming/src/main/scala/org/apache/spark/streaming/ui/UIUtils.scala
index 9b1c939e93..84ecf81abf 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/ui/UIUtils.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/ui/UIUtils.scala
@@ -18,7 +18,7 @@
 package org.apache.spark.streaming.ui
 
 import java.text.SimpleDateFormat
-import java.util.TimeZone
+import java.util.{Locale, TimeZone}
 import java.util.concurrent.TimeUnit
 
 import scala.xml.Node
@@ -80,11 +80,13 @@ private[streaming] object UIUtils {
 
   // SimpleDateFormat is not thread-safe. Don't expose it to avoid improper use.
   private val batchTimeFormat = new ThreadLocal[SimpleDateFormat]() {
-    override def initialValue(): SimpleDateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss")
+    override def initialValue(): SimpleDateFormat =
+      new SimpleDateFormat("yyyy/MM/dd HH:mm:ss", Locale.US)
   }
 
   private val batchTimeFormatWithMilliseconds = new ThreadLocal[SimpleDateFormat]() {
-    override def initialValue(): SimpleDateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss.SSS")
+    override def initialValue(): SimpleDateFormat =
+      new SimpleDateFormat("yyyy/MM/dd HH:mm:ss.SSS", Locale.US)
   }
 
   /**