IN
- The type of the input value.OUT
- The type of the output value.KEY
- The type of the key.W
- The type of Window
that this window function can be applied on.@Public public interface WindowFunction<IN,OUT,KEY,W extends Window> extends org.apache.flink.api.common.functions.Function, Serializable
void apply(KEY key, W window, Iterable<IN> input, org.apache.flink.util.Collector<OUT> out) throws Exception
key
- The key for which this window is evaluated.window
- The window that is being evaluated.input
- The elements in the window being evaluated.out
- A collector for emitting elements.Exception
- The function may throw exceptions to fail the program and trigger recovery.Copyright © 2014–2019 The Apache Software Foundation. All rights reserved.