[SPARK-12136] [STREAMING] rddToFileName does not properly handle prefix and suffix parameters

[bomeng]

The original code does not properly handle the cases where the prefix is null, but suffix is not null - the suffix should be used but is not.

The fix is using StringBuilder to construct the proper file name.

[srowen]

I think it's fine; it might be simpler without bothering with StringBuilder but not by much.
(In your code you should use val result and you do not need to assign result each time.)

var result = time.milliseconds.toString
if (prefix != null && prefix.length > 0) {
  result = prefix + "-" result
}
if (suffix != null && suffix.length > 0) {
  result = result + "." + suffix
}
result

[bomeng]

The code was changed according to your comments by using String instead.

[SparkQA]

Test build #2179 has finished for PR 10185 at commit 21d7bcd.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):\n * public class JavaQuantileDiscretizerExample\n * public abstract static class PrefixComputer\n

[tdas]

lets use string interpolation for this.

[srowen]

LGTM

[SparkQA]

Test build #2189 has finished for PR 10185 at commit 4d82c43.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):\n * public class JavaQuantileDiscretizerExample\n * public abstract static class PrefixComputer\n

[srowen]

Merged to master/1.6