ProcessJoinFunction (Flink : Runtime 2.0.0 API)

java.lang.Object
- org.apache.flink.api.common.functions.AbstractRichFunction
- - org.apache.flink.streaming.api.functions.co.ProcessJoinFunction<IN1,IN2,OUT>

Type Parameters:

IN1 - Type of the first input

IN2 - Type of the second input

OUT - Type of the output

All Implemented Interfaces:

Serializable, org.apache.flink.api.common.functions.Function, org.apache.flink.api.common.functions.RichFunction
```
@PublicEvolving
public abstract class ProcessJoinFunction<IN1,IN2,OUT>
extends org.apache.flink.api.common.functions.AbstractRichFunction
```
A function that processes two joined elements and produces a single output one.
This function will get called for every joined pair of elements the joined two streams. The timestamp of the joined pair as well as the timestamp of the left element and the right element can be accessed through the ProcessJoinFunction.Context.

See Also:

Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`class`	`ProcessJoinFunction.Context`	The context that is available during an invocation of `#processElement(Object, Object, Context, Collector)`.

Constructor Summary

Constructors
Constructor Description

ProcessJoinFunction()

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`abstract void`	`processElement(IN1 left, IN2 right, ProcessJoinFunction.Context ctx, org.apache.flink.util.Collector<OUT> out)`	This method is called for each joined pair of elements.

Methods inherited from class org.apache.flink.api.common.functions.AbstractRichFunction
close, getIterationRuntimeContext, getRuntimeContext, open, setRuntimeContext

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ProcessJoinFunction
```
public ProcessJoinFunction()
```
- Method Detail
  - processElement
```
public abstract void processElement(IN1 left,
                                    IN2 right,
                                    ProcessJoinFunction.Context ctx,
                                    org.apache.flink.util.Collector<OUT> out)
                             throws Exception
```
    This method is called for each joined pair of elements. It can output zero or more elements through the provided Collector and has access to the timestamps of the joined elements and the result through the ProcessJoinFunction.Context.
    
    Parameters:
    
    left - The left element of the joined pair.
    
    right - The right element of the joined pair.
    
    ctx - A context that allows querying the timestamps of the left, right and joined pair. In addition, this context allows to emit elements on a side output.
    
    out - The collector to emit resulting elements to.
    
    Throws:
    
    Exception - This function may throw exceptions which cause the streaming program to fail and go in recovery mode.