[FLINK-10359] Scala example in DataSet docs is broken

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.5.3, 1.6.0, 1.7.0
• Fix Version/s: 1.6.3, 1.7.1, 1.8.0
• Component/s: Documentation
• Labels: pull-request-available
• Assignee: vinoyang
• Reporter: Fabian Hueske
• Created: 17/Sep/18 21:28
• Updated: 15/Mar/19 12:21
• Resolved: 11/Dec/18 13:50

Description

The Scala example of https://ci.apache.org/projects/flink/flink-docs-release-1.6/dev/batch/dataset_transformations.html#combinable-groupreducefunctions is broken.

The asScala and the reduce call fetch the Java Iterator which may only fetched once.

The Iterable can be iterated over only once. Only the first call to 'iterator()' will succeed.

While we are on it, it would make sense to check the other examples as well.

Issue Links

• links to: GitHub Pull Request #7266