[SPARK-13823][CORE][STREAMING][SQL] Always specify Charset in String <-> byte[] conversions (and remaining Coverity items)

## What changes were proposed in this pull request?

- Fixes calls to `new String(byte[])` or `String.getBytes()` that rely on platform default encoding, to use UTF-8
- Same for `InputStreamReader` and `OutputStreamWriter` constructors
- Standardizes on UTF-8 everywhere
- Standardizes specifying the encoding with `StandardCharsets.UTF-8`, not the Guava constant or "UTF-8" (which means handling `UnuspportedEncodingException`)
- (also addresses the other remaining Coverity scan issues, which are pretty trivial; these are separated into commit https://github.com/srowen/spark/commit/1deecd8d9ca986d8adb1a42d315890ce5349d29c )

## How was this patch tested?

Jenkins tests

Author: Sean Owen <sowen@cloudera.com>

Closes #11657 from srowen/SPARK-13823.

1 files changed, 3 insertions, 1 deletions

diff --git a/streaming/src/main/scala/org/apache/spark/streaming/dstream/SocketInputDStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/dstream/SocketInputDStream.scala
index 4414774791..f7519c10c8 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/dstream/SocketInputDStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/dstream/SocketInputDStream.scala
@@ -19,6 +19,7 @@ package org.apache.spark.streaming.dstream
 
 import java.io._
 import java.net.{ConnectException, Socket}
+import java.nio.charset.StandardCharsets
 
 import scala.reflect.ClassTag
 import scala.util.control.NonFatal
@@ -113,7 +114,8 @@ object SocketReceiver  {
    * to '\n' delimited strings and returns an iterator to access the strings.
    */
   def bytesToLines(inputStream: InputStream): Iterator[String] = {
-    val dataInputStream = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"))
+    val dataInputStream = new BufferedReader(
+      new InputStreamReader(inputStream, StandardCharsets.UTF_8))
     new NextIterator[String] {
       protected override def getNext() = {
         val nextValue = dataInputStream.readLine()