public class NullBinaryRowKeySelector extends Object implements BaseRowKeySelector
Modifier and Type | Field and Description |
---|---|
static NullBinaryRowKeySelector |
INSTANCE |
Constructor and Description |
---|
NullBinaryRowKeySelector() |
Modifier and Type | Method and Description |
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BaseRow |
getKey(BaseRow value)
User-defined function that deterministically extracts the key from an object.
|
BaseRowTypeInfo |
getProducedType()
Gets the data type (as a
TypeInformation ) produced by this function or input format. |
public static final NullBinaryRowKeySelector INSTANCE
public BaseRow getKey(BaseRow value) throws Exception
KeySelector
For example for a class:
public class Word { String word; int count; }The key extractor could return the word as a key to group all Word objects by the String they contain.
The code would look like this
public String getKey(Word w) { return w.word; }
getKey
in interface KeySelector<BaseRow,BaseRow>
value
- The object to get the key from.Exception
- Throwing an exception will cause the execution of the respective task to fail,
and trigger recovery or cancellation of the program.public BaseRowTypeInfo getProducedType()
ResultTypeQueryable
TypeInformation
) produced by this function or input format.getProducedType
in interface ResultTypeQueryable<BaseRow>
getProducedType
in interface BaseRowKeySelector
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