[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, 2 insertions, 1 deletions

diff --git a/mllib/src/main/scala/org/apache/spark/mllib/api/python/PythonMLLibAPI.scala b/mllib/src/main/scala/org/apache/spark/mllib/api/python/PythonMLLibAPI.scala
index 132dc174a8..53935f328a 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/api/python/PythonMLLibAPI.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/api/python/PythonMLLibAPI.scala
@@ -19,6 +19,7 @@ package org.apache.spark.mllib.api.python
 
 import java.io.OutputStream
 import java.nio.{ByteBuffer, ByteOrder}
+import java.nio.charset.StandardCharsets
 import java.util.{ArrayList => JArrayList, List => JList, Map => JMap}
 
 import scala.collection.JavaConverters._
@@ -1226,7 +1227,7 @@ private[spark] object SerDe extends Serializable {
     def pickle(obj: Object, out: OutputStream, pickler: Pickler): Unit = {
       if (obj == this) {
         out.write(Opcodes.GLOBAL)
-        out.write((module + "\n" + name + "\n").getBytes)
+        out.write((module + "\n" + name + "\n").getBytes(StandardCharsets.UTF_8))
       } else {
         pickler.save(this)  // it will be memorized by Pickler
         saveState(obj, out, pickler)