[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.

2 files changed, 5 insertions, 4 deletions

diff --git a/external/flume/src/main/scala/org/apache/spark/streaming/flume/FlumeTestUtils.scala b/external/flume/src/main/scala/org/apache/spark/streaming/flume/FlumeTestUtils.scala
index 3f87ce46e5..945cfa7295 100644
--- a/external/flume/src/main/scala/org/apache/spark/streaming/flume/FlumeTestUtils.scala
+++ b/external/flume/src/main/scala/org/apache/spark/streaming/flume/FlumeTestUtils.scala
@@ -19,12 +19,12 @@ package org.apache.spark.streaming.flume
 
 import java.net.{InetSocketAddress, ServerSocket}
 import java.nio.ByteBuffer
+import java.nio.charset.StandardCharsets
 import java.util.{List => JList}
 import java.util.Collections
 
 import scala.collection.JavaConverters._
 
-import com.google.common.base.Charsets.UTF_8
 import org.apache.avro.ipc.NettyTransceiver
 import org.apache.avro.ipc.specific.SpecificRequestor
 import org.apache.commons.lang3.RandomUtils
@@ -65,7 +65,7 @@ private[flume] class FlumeTestUtils {
 
     val inputEvents = input.asScala.map { item =>
       val event = new AvroFlumeEvent
-      event.setBody(ByteBuffer.wrap(item.getBytes(UTF_8)))
+      event.setBody(ByteBuffer.wrap(item.getBytes(StandardCharsets.UTF_8)))
       event.setHeaders(Collections.singletonMap("test", "header"))
       event
     }
diff --git a/external/flume/src/main/scala/org/apache/spark/streaming/flume/PollingFlumeTestUtils.scala b/external/flume/src/main/scala/org/apache/spark/streaming/flume/PollingFlumeTestUtils.scala
index 9515d07c5e..1a96df6e94 100644
--- a/external/flume/src/main/scala/org/apache/spark/streaming/flume/PollingFlumeTestUtils.scala
+++ b/external/flume/src/main/scala/org/apache/spark/streaming/flume/PollingFlumeTestUtils.scala
@@ -17,12 +17,12 @@
 
 package org.apache.spark.streaming.flume
 
+import java.nio.charset.StandardCharsets
 import java.util.{Collections, List => JList, Map => JMap}
 import java.util.concurrent._
 
 import scala.collection.mutable.ArrayBuffer
 
-import com.google.common.base.Charsets.UTF_8
 import org.apache.flume.event.EventBuilder
 import org.apache.flume.Context
 import org.apache.flume.channel.MemoryChannel
@@ -193,7 +193,8 @@ private[flume] class PollingFlumeTestUtils {
         val tx = channel.getTransaction
         tx.begin()
         for (j <- 0 until eventsPerBatch) {
-          channel.put(EventBuilder.withBody(s"${channel.getName}-$t".getBytes(UTF_8),
+          channel.put(EventBuilder.withBody(
+            s"${channel.getName}-$t".getBytes(StandardCharsets.UTF_8),
             Collections.singletonMap(s"test-$t", "header")))
           t += 1
         }