[SPARK-21578] Add JavaSparkContextSuite

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.3.0
• Fix Version/s: 2.3.0
• Component/s: Spark Core
• Assignee: Dongjoon Hyun
• Reporter: Dongjoon Hyun
• Created: 30/Jul/17 22:22
• Updated: 23/Aug/17 18:08
• Resolved: 02/Aug/17 04:59

Description

Due to SI-8479, SPARK-1093 introduced redundant SparkContext constructors. However, SI-8479 is already fixed in Scala 2.10.5 and Scala 2.11.1.

The real reason to provide this constructor is that Java code can access `SparkContext` directly. It's Scala behavior, SI-4278. So, this PR adds an explicit testsuite, `JavaSparkContextSuite` to prevent future regression, and fixes the outdate comment, too.