FilterFunction (Flink : Core 1.20.1-cp1 API)

Type Parameters:

T - The type of the filtered elements.

All Superinterfaces:

org.apache.flink.api.common.functions.Function, Serializable

All Known Implementing Classes:

RichFilterFunction

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
```
@Public
@FunctionalInterface
public interface FilterFunction<T>
extends org.apache.flink.api.common.functions.Function, Serializable
```
A filter function is a predicate applied individually to each record. The predicate decides whether to keep the element, or to discard it.
The basic syntax for using a FilterFunction is as follows:
```
 DataSet<X> input = ...;

 DataSet<X> result = input.filter(new MyFilterFunction());
 
```
IMPORTANT: The system assumes that the function does not modify the elements on which the predicate is applied. Violating this assumption can lead to incorrect results.

- Method Summary
  
  All Methods Instance Methods Abstract Methods
  Modifier and Type Method Description
  
  boolean filter(T value)
  The filter function that evaluates the predicate.

- Method Detail
  - filter
```
boolean filter(T value)
        throws Exception
```
    The filter function that evaluates the predicate.
    IMPORTANT: The system assumes that the function does not modify the elements on which the predicate is applied. Violating this assumption can lead to incorrect results.
    
    Parameters:
    
    value - The value to be filtered.
    
    Returns:
    
    True for values that should be retained, false for values to be filtered out.
    
    Throws:
    
    Exception - This method may throw exceptions. Throwing an exception will cause the operation to fail and may trigger recovery.