[SPARK-9534] [BUILD] Enable javac lint for scalac parity; fix a lot of build warnings, 1.5.0 edition

Enable most javac lint warnings; fix a lot of build warnings. In a few cases, touch up surrounding code in the process.

I'll explain several of the changes inline in comments.

Author: Sean Owen <sowen@cloudera.com>

Closes #7862 from srowen/SPARK-9534 and squashes the following commits:

ea51618 [Sean Owen] Enable most javac lint warnings; fix a lot of build warnings. In a few cases, touch up surrounding code in the process.

2 files changed, 3 insertions, 2 deletions

diff --git a/examples/src/main/java/org/apache/spark/examples/ml/JavaOneVsRestExample.java b/examples/src/main/java/org/apache/spark/examples/ml/JavaOneVsRestExample.java
index 75063dbf80..e7f2f6f615 100644
--- a/examples/src/main/java/org/apache/spark/examples/ml/JavaOneVsRestExample.java
+++ b/examples/src/main/java/org/apache/spark/examples/ml/JavaOneVsRestExample.java
@@ -178,6 +178,7 @@ public class JavaOneVsRestExample {
     return params;
   }
 
+  @SuppressWarnings("static")
   private static Options generateCommandlineOptions() {
     Option input = OptionBuilder.withArgName("input")
       .hasArg()
diff --git a/examples/src/main/java/org/apache/spark/examples/streaming/JavaStatefulNetworkWordCount.java b/examples/src/main/java/org/apache/spark/examples/streaming/JavaStatefulNetworkWordCount.java
index dbf2ef02d7..02f58f48b0 100644
--- a/examples/src/main/java/org/apache/spark/examples/streaming/JavaStatefulNetworkWordCount.java
+++ b/examples/src/main/java/org/apache/spark/examples/streaming/JavaStatefulNetworkWordCount.java
@@ -85,7 +85,7 @@ public class JavaStatefulNetworkWordCount {
     @SuppressWarnings("unchecked")
     List<Tuple2<String, Integer>> tuples = Arrays.asList(new Tuple2<String, Integer>("hello", 1),
             new Tuple2<String, Integer>("world", 1));
-    JavaPairRDD<String, Integer> initialRDD = ssc.sc().parallelizePairs(tuples);
+    JavaPairRDD<String, Integer> initialRDD = ssc.sparkContext().parallelizePairs(tuples);
 
     JavaReceiverInputDStream<String> lines = ssc.socketTextStream(
             args[0], Integer.parseInt(args[1]), StorageLevels.MEMORY_AND_DISK_SER_2);
@@ -107,7 +107,7 @@ public class JavaStatefulNetworkWordCount {
 
     // This will give a Dstream made of state (which is the cumulative count of the words)
     JavaPairDStream<String, Integer> stateDstream = wordsDstream.updateStateByKey(updateFunction,
-            new HashPartitioner(ssc.sc().defaultParallelism()), initialRDD);
+            new HashPartitioner(ssc.sparkContext().defaultParallelism()), initialRDD);
 
     stateDstream.print();
     ssc.start();