kafka-streams-Window.adoc

Window

Window is the base of single window instances that are described by the start and end timestamps and can be checked if they overlap.

package org.apache.kafka.streams.kstream;

abstract class Window {
  // only required methods that have no implementation
  // the others follow
  public abstract boolean overlap(final Window other);
}

Table 1. (Subset of) Window Contract

Method	Description
overlap	Checks whether a window overlaps with another.

Use start method to access the start timestamp of a window.

long start()

Use end method to access the end timestamp of a window.

long end()

Window has the following text representation:

Window{start=[startMs], end=[endMs]}

Table 2. Windows

Window	Description
SessionWindow
TimeWindow
UnlimitedWindow

Creating Window Instance

Window takes the following when created:

• The start timestamp of the window (in milliseconds)

• The end timestamp of the window (in milliseconds)

Window initializes the internal registries and counters.

Window is created when…​MEFIXME

Window is created along with…​MEFIXME

Note	Window is a Java/Scala abstract class and cannot be created directly. It is created indirectly when the concrete FIXMEs are.