Package org.apache.beam.sdk.transforms

Class ToString

java.lang.Object

org.apache.beam.sdk.transforms.ToString

public final class ToString
extends Object

PTransforms for converting a PCollection<?>, PCollection<KV<?,?>>, or PCollection<Iterable<?>> to a PCollection<String>.

Note: For any custom string conversion and formatting, we recommend applying your own ProcessFunction using MapElements.via(ProcessFunction)

Method Summary

Modifier and Type	Method	Description
static PTransform<PCollection<?>,PCollection<String>>	elements()	Transforms each element of the input PCollection to a String using the Object.toString() method.
static PTransform<PCollection<? extends Iterable<?>>,PCollection<String>>	iterables()	Transforms each item in the iterable of the input PCollection to a String using the Object.toString() method followed by a "," until the last element in the iterable.
static PTransform<PCollection<? extends Iterable<?>>,PCollection<String>>	iterables(String delimiter)	Transforms each item in the iterable of the input PCollection to a String using the Object.toString() method followed by the specified delimiter until the last element in the iterable.
static PTransform<PCollection<? extends KV<?,?>>,PCollection<String>>	kvs()	Transforms each element of the input PCollection to a String by using the Object.toString() on the key followed by a "," followed by the Object.toString() of the value.
static PTransform<PCollection<? extends KV<?,?>>,PCollection<String>>	kvs(String delimiter)	Transforms each element of the input PCollection to a String by using the Object.toString() on the key followed by the specified delimiter followed by the Object.toString() of the value.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

elements

public static PTransform<PCollection<?>,PCollection<String>> elements()

Transforms each element of the input PCollection to a String using the Object.toString() method.

kvs

public static PTransform<PCollection<? extends KV<?,?>>,PCollection<String>> kvs()

Transforms each element of the input PCollection to a String by using the Object.toString() on the key followed by a "," followed by the Object.toString() of the value.

kvs

public static PTransform<PCollection<? extends KV<?,?>>,PCollection<String>> kvs(String delimiter)

Transforms each element of the input PCollection to a String by using the Object.toString() on the key followed by the specified delimiter followed by the Object.toString() of the value.

Parameters:

delimiter - The delimiter to put between the key and value

iterables

public static PTransform<PCollection<? extends Iterable<?>>,PCollection<String>> iterables()

Transforms each item in the iterable of the input PCollection to a String using the Object.toString() method followed by a "," until the last element in the iterable. There is no trailing delimiter.

iterables

public static PTransform<PCollection<? extends Iterable<?>>,PCollection<String>> iterables(String delimiter)

Transforms each item in the iterable of the input PCollection to a String using the Object.toString() method followed by the specified delimiter until the last element in the iterable. There is no trailing delimiter.

Parameters:

delimiter - The delimiter to put between the items in the iterable.