[MINOR] Resolve a number of miscellaneous build warnings

## What changes were proposed in this pull request?

This change resolves a number of build warnings that have accumulated, before 2.x. It does not address a large number of deprecation warnings, especially related to the Accumulator API. That will happen separately.

## How was this patch tested?

Jenkins

Author: Sean Owen <sowen@cloudera.com>

Closes #13377 from srowen/BuildWarnings.

1 files changed, 3 insertions, 1 deletions

diff --git a/mllib/src/test/java/org/apache/spark/mllib/fpm/JavaPrefixSpanSuite.java b/mllib/src/test/java/org/apache/spark/mllib/fpm/JavaPrefixSpanSuite.java
index 75b0ec6480..32d3141149 100644
--- a/mllib/src/test/java/org/apache/spark/mllib/fpm/JavaPrefixSpanSuite.java
+++ b/mllib/src/test/java/org/apache/spark/mllib/fpm/JavaPrefixSpanSuite.java
@@ -72,7 +72,9 @@ public class JavaPrefixSpanSuite extends SharedSparkSession {
 
     try {
       model.save(spark.sparkContext(), outputPath);
-      PrefixSpanModel newModel = PrefixSpanModel.load(spark.sparkContext(), outputPath);
+      @SuppressWarnings("unchecked")
+      PrefixSpanModel<Integer> newModel =
+          (PrefixSpanModel<Integer>) PrefixSpanModel.load(spark.sparkContext(), outputPath);
       JavaRDD<FreqSequence<Integer>> freqSeqs = newModel.freqSequences().toJavaRDD();
       List<FreqSequence<Integer>> localFreqSeqs = freqSeqs.collect();
       Assert.assertEquals(5, localFreqSeqs.size());