org.apache.flink.streaming.api.scala
ConnectedStreams
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package scala
Applies a CoFlatMap transformation on the connected streams.
Applies a CoFlatMap transformation on the connected streams.
The transformation consists of two separate functions, where the first one is called for each element of the first connected stream, and the second one is called for each element of the second connected stream.
Function called per element of the first input.
Function called per element of the second input.
The resulting data stream.
Applies a CoFlatMap transformation on the connected streams.
Applies a CoFlatMap transformation on the connected streams.
The transformation consists of two separate functions, where the first one is called for each element of the first connected stream, and the second one is called for each element of the second connected stream.
Function called per element of the first input.
Function called per element of the second input.
The resulting data stream.
Applies a CoFlatMap transformation on these connected streams.
Applies a CoFlatMap transformation on these connected streams.
The transformation calls CoFlatMapFunction#flatMap1 for each element in the first stream and CoFlatMapFunction#flatMap2 for each element of the second stream.
On can pass a subclass of org.apache.flink.streaming.api.functions.co.RichCoFlatMapFunction to gain access to the org.apache.flink.api.common.functions.RuntimeContext and to additional life cycle methods.
The CoFlatMapFunction used to transform the two connected streams
The resulting data stream.
Keys the two connected streams together.
Keys the two connected streams together. After this operation, all elements with the same key from both streams will be sent to the same parallel instance of the transformation functions.
The first stream's key function
The second stream's key function
The key-grouped connected streams
Keys the two connected streams together.
Keys the two connected streams together. After this operation, all elements with the same key from both streams will be sent to the same parallel instance of the transformation functions.
The first stream's key expressions
The second stream's key expressions
The key-grouped connected streams
Keys the two connected streams together.
Keys the two connected streams together. After this operation, all elements with the same key from both streams will be sent to the same parallel instance of the transformation functions.
The first stream's key expression
The second stream's key expression
The key-grouped connected streams
Keys the two connected streams together.
Keys the two connected streams together. After this operation, all elements with the same key from both streams will be sent to the same parallel instance of the transformation functions.
The first stream's key fields
The second stream's key fields
The key-grouped connected streams
Keys the two connected streams together.
Keys the two connected streams together. After this operation, all elements with the same key from both streams will be sent to the same parallel instance of the transformation functions.
The first stream's key field
The second stream's key field
The key-grouped connected streams
Applies a CoMap transformation on these connected streams.
Applies a CoMap transformation on these connected streams.
The transformation calls CoMapFunction#map1 for each element in the first stream and CoMapFunction#map2 for each element of the second stream.
On can pass a subclass of org.apache.flink.streaming.api.functions.co.RichCoMapFunction to gain access to the org.apache.flink.api.common.functions.RuntimeContext and to additional life cycle methods.
The CoMapFunction used to transform the two connected streams
The resulting data stream
Applies a CoMap transformation on the connected streams.
Applies a CoMap transformation on the connected streams.
The transformation consists of two separate functions, where the first one is called for each element of the first connected stream, and the second one is called for each element of the second connected stream.
Function called per element of the first input.
Function called per element of the second input.
The resulting data stream.
Applies the given CoProcessFunction on the connected input streams, thereby creating a transformed output stream.
Applies the given CoProcessFunction on the connected input streams, thereby creating a transformed output stream.
The function will be called for every element in the input streams and can produce zero or more output elements. Contrary to the flatMap(CoFlatMapFunction) function, this function can also query the time and set timers. When reacting to the firing of set timers the function can directly emit elements and/or register yet more timers.
A RichCoProcessFunction can be used to gain access to features provided by the org.apache.flink.api.common.functions.RichFunction interface.
The CoProcessFunction that is called for each element in the stream.
The transformed DataStream.
ConnectedStreams represents two connected streams of (possibly) different data types. Connected streams are useful for cases where operations on one stream directly affect the operations on the other stream, usually via shared state between the streams.
An example for the use of connected streams would be to apply rules that change over time onto another stream. One of the connected streams has the rules, the other stream the elements to apply the rules to. The operation on the connected stream maintains the current set of rules in the state. It may receive either a rule update and update the state or a data element and apply the rules in the state to the element.
The connected stream can be conceptually viewed as a union stream of an Either type, that holds either the first stream's type or the second stream's type.