GeneratorFunction (Flink : 2.0-SNAPSHOT API)

Type Parameters:

T - Type of the input elements.

O - Type of the returned elements.

All Superinterfaces:

Function, Serializable

All Known Implementing Classes:

CarGeneratorFunction, EventsGeneratorFunction, FromElementsGeneratorFunction, IndexLookupGeneratorFunction
```
@Experimental
public interface GeneratorFunction<T,O>
extends Function
```
Base interface for data generator functions. Data generator functions take elements and transform them, element-wise. They are the core building block of the DataGeneratorSource that drives the data generation process by supplying "index" values of type Long. It makes it possible to produce specific elements at concrete positions of the generated data stream.
Example:
```
 GeneratorFunction<Long, String> generatorFunction = index -> "Number: " + index;
 DataGeneratorSource<String> source =
         new DataGeneratorSource<>(generatorFunction, 1000, Types.STRING);
 
```

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`default void`	`close()`	Tear-down method for the function.
`O`	`map(T value)`
`default void`	`open(SourceReaderContext readerContext)`	Initialization method for the function.

- Method Detail
  - open
```
default void open(SourceReaderContext readerContext)
           throws Exception
```
    Initialization method for the function. It is called once before the actual data mapping methods.
    
    Throws:
    
    Exception
  - close
```
default void close()
            throws Exception
```
    Tear-down method for the function.
    
    Throws:
    
    Exception
  - map
```
O map(T value)
throws Exception
```
    Throws:
    
    Exception