RichReduceFunction (Flink : Core 1.18.1-cp1 API)

java.lang.Object
- org.apache.flink.api.common.functions.AbstractRichFunction
- - org.apache.flink.api.common.functions.RichReduceFunction<T>

Type Parameters:

T - Type of the elements that this function processes.

All Implemented Interfaces:

Serializable, Function, ReduceFunction<T>, RichFunction
```
@Public
public abstract class RichReduceFunction<T>
extends AbstractRichFunction
implements ReduceFunction<T>
```
Rich variant of the ReduceFunction. As a RichFunction, it gives access to the RuntimeContext and provides setup and teardown methods: RichFunction.open(org.apache.flink.configuration.Configuration) and RichFunction.close().

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor Description

RichReduceFunction()

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`abstract T`	`reduce(T value1, T value2)`	The core method of ReduceFunction, combining two values into one value of the same type.

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
  - RichReduceFunction
```
public RichReduceFunction()
```
- Method Detail
  - reduce
```
public abstract T reduce(T value1,
                         T value2)
                  throws Exception
```
    Description copied from interface: ReduceFunction
    
    The core method of ReduceFunction, combining two values into one value of the same type. The reduce function is consecutively applied to all values of a group until only a single value remains.
    
    Specified by:
    
    reduce in interface ReduceFunction<T>
    
    Parameters:
    
    value1 - The first value to combine.
    
    value2 - The second value to combine.
    
    Returns:
    
    The combined value of both input values.
    
    Throws:
    
    Exception - This method may throw exceptions. Throwing an exception will cause the operation to fail and may trigger recovery.