org.apache.flink.table.runtime.operators.window.assigners

类 WindowAssigner<W extends Window>

java.lang.Object

org.apache.flink.table.runtime.operators.window.assigners.WindowAssigner<W>

类型参数:

W - The type of Window that this assigner assigns.

所有已实现的接口:

Serializable

直接已知子类:

CountSlidingWindowAssigner, CountTumblingWindowAssigner, MergingWindowAssigner, PanedWindowAssigner, TumblingWindowAssigner

public abstract class WindowAssigner<W extends Window>
extends Object
implements Serializable

A WindowAssigner assigns zero or more Windows to an element.

In a window operation, elements are grouped by their key (if available) and by the windows to which it was assigned. The set of elements with the same key and window is called a pane. When a Trigger decides that a certain pane should fire the window to produce output elements for that pane.

另请参阅:

序列化表格

构造器概要

构造器

构造器和说明
WindowAssigner()

方法概要

限定符和类型	方法和说明
abstract Collection<W>	assignWindows(org.apache.flink.table.data.RowData element, long timestamp) Given the timestamp and element, returns the set of windows into which it should be placed.
abstract org.apache.flink.api.common.typeutils.TypeSerializer<W>	getWindowSerializer(org.apache.flink.api.common.ExecutionConfig executionConfig) Returns a TypeSerializer for serializing windows that are assigned by this WindowAssigner.
abstract boolean	isEventTime() Returns true if elements are assigned to windows based on event time, false otherwise.
void	open(InternalWindowProcessFunction.Context<?,W> ctx) Initialization method for the function.
abstract String	toString()

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

构造器详细资料

WindowAssigner

public WindowAssigner()

方法详细资料

open

public void open(InternalWindowProcessFunction.Context<?,W> ctx)
          throws Exception

Initialization method for the function. It is called before the actual working methods.

抛出:

Exception

assignWindows

public abstract Collection<W> assignWindows(org.apache.flink.table.data.RowData element,
                                            long timestamp)
                                     throws IOException

Given the timestamp and element, returns the set of windows into which it should be placed.

参数:

element - The element to which windows should be assigned.

timestamp - The timestamp of the element when isEventTime() returns true, or the current system time when isEventTime() returns false.

抛出:

IOException

getWindowSerializer

public abstract org.apache.flink.api.common.typeutils.TypeSerializer<W> getWindowSerializer(org.apache.flink.api.common.ExecutionConfig executionConfig)

Returns a TypeSerializer for serializing windows that are assigned by this WindowAssigner.

isEventTime

public abstract boolean isEventTime()

Returns true if elements are assigned to windows based on event time, false otherwise.

toString

public abstract String toString()

覆盖:

toString 在类中 Object