Josh Rosen 0f673c21f6 [SPARK-3266] Use intermediate abstract classes to fix type erasure issues in Java APIs ... This PR addresses a Scala compiler bug ([SI-8905](https://issues.scala-lang.org/browse/SI-8905)) that was breaking some of the Spark Java APIs. In a nutshell, it seems that methods whose implementations are inherited from generic traits sometimes have their type parameters erased to Object. This was causing methods like `DoubleRDD.min()` to throw confusing NoSuchMethodErrors at runtime. The fix implemented here is to introduce an intermediate layer of abstract classes and inherit from those instead of directly extends the `Java*Like` traits. This should not break binary compatibility. I also improved the test coverage of the Java API, adding several new tests for methods that failed at runtime due to this bug. Author: Josh Rosen <joshrosen@databricks.com> Closes #5050 from JoshRosen/javardd-si-8905-fix and squashes the following commits: 2feb068 [Josh Rosen] Use intermediate abstract classes to work around SPARK-3266 d5f3e5d [Josh Rosen] Add failing regression tests for SPARK-3266		2015-03-17 09:18:57 -07:00
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org/apache/spark	[SPARK-3266] Use intermediate abstract classes to fix type erasure issues in Java APIs	2015-03-17 09:18:57 -07:00
test/org/apache/spark	[SPARK-5549] Define TaskContext interface in Scala.	2015-02-03 00:46:04 -08:00