RichAggregateFunction (Flink : Core 1.20.1-cp1 API)

java.lang.Object
- org.apache.flink.api.common.functions.AbstractRichFunction
- - org.apache.flink.api.common.functions.RichAggregateFunction<IN,ACC,OUT>

Type Parameters:

IN - The type of the values that are aggregated (input values)

ACC - The type of the accumulator (intermediate aggregate state).

OUT - The type of the aggregated result

All Implemented Interfaces:

Serializable, org.apache.flink.api.common.functions.AggregateFunction<IN,ACC,OUT>, org.apache.flink.api.common.functions.Function, RichFunction
```
@PublicEvolving
public abstract class RichAggregateFunction<IN,ACC,OUT>
extends AbstractRichFunction
implements org.apache.flink.api.common.functions.AggregateFunction<IN,ACC,OUT>
```
Rich variant of the AggregateFunction. As a RichFunction, it gives access to the RuntimeContext and provides setup and teardown methods: RichFunction.open(OpenContext) and RichFunction.close().

See Also:

AggregateFunction, Serialized Form

Constructor Summary

Constructors
Constructor Description

RichAggregateFunction()

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`abstract ACC`	`add(IN value, ACC accumulator)`
`abstract ACC`	`createAccumulator()`
`abstract OUT`	`getResult(ACC accumulator)`
`abstract ACC`	`merge(ACC a, ACC b)`

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

Methods inherited from interface org.apache.flink.api.common.functions.RichFunction
open

- Constructor Detail
  - RichAggregateFunction
```
public RichAggregateFunction()
```
- Method Detail
  - createAccumulator
```
public abstract ACC createAccumulator()
```
    Specified by:
    
    createAccumulator in interface org.apache.flink.api.common.functions.AggregateFunction<IN,ACC,OUT>
  - add
```
public abstract ACC add(IN value,
                        ACC accumulator)
```
    Specified by:
    
    add in interface org.apache.flink.api.common.functions.AggregateFunction<IN,ACC,OUT>
  - getResult
```
public abstract OUT getResult(ACC accumulator)
```
    Specified by:
    
    getResult in interface org.apache.flink.api.common.functions.AggregateFunction<IN,ACC,OUT>
  - merge
```
public abstract ACC merge(ACC a,
                          ACC b)
```
    Specified by:
    
    merge in interface org.apache.flink.api.common.functions.AggregateFunction<IN,ACC,OUT>