[FLINK-701] Change new Java API functions to SAMs

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.6-incubating
• Labels: github-import
• Assignee: Kostas Tzoumas
• Reporter: GitHub Import
• Created: 09/Jun/14 12:47
• Updated: 28/Feb/19 14:29
• Resolved: 01/Aug/14 00:46

Description

In order to support a compact syntax with Java 8 Lambdas, we would need to change the types of the functions to Single Abstract Method types (SAMs). Only those can be implemented by Lambdas.

That means that DataSet.map(MapFunction) would accept an interface MapFunction, not the abstract class that we use now. Many UDFs would not inherit form `AbstractFunction` any more. The inheritance from AbstractFunction would be optional, if life cycle methods (open / close) and runtime contexts are needed.

This may have also implications on the type extraction, as the generic parameters are in generic superinterfaces, rather than in generic superclasses.

---------------- Imported from GitHub ----------------
Url: https://github.com/stratosphere/stratosphere/issues/701
Created by: StephanEwen
Labels: enhancement, java api, user satisfaction,
Milestone: Release 0.6 (unplanned)
Created at: Thu Apr 17 13:06:40 CEST 2014
State: open

Issue Links

• blocks: FLINK-612 Add Java 8 Lambda support to new Java API
• is related to: FLINK-612 Add Java 8 Lambda support to new Java API

Sub-Tasks

• Move combine() from GroupReduceFunction to Interface: Closed