Package org.apache.kafka.streams.kstream

Class Printed<K,V>

java.lang.Object

org.apache.kafka.streams.kstream.Printed<K,V>

Type Parameters:

K - key type

V - value type

public class Printed<K,V>
extends java.lang.Object

An object to define the options used when printing a KStream.

See Also:

KStream.print(Printed)

Field Summary

Fields

Modifier and Type	Field	Description
protected java.lang.String	label
protected KeyValueMapper<? super K,? super V,java.lang.String>	mapper
protected java.io.PrintWriter	printWriter

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Printed(Printed<K,V> printed)	Copy constructor.

Method Summary

Modifier and Type	Method	Description
static <K,V> Printed<K,V>	toFile(java.lang.String filePath)	Print the records of a KStream to a file.
static <K,V> Printed<K,V>	toSysOut()	Print the records of a KStream to system out.
Printed<K,V>	withKeyValueMapper(KeyValueMapper<? super K,? super V,java.lang.String> mapper)	Print the records of a KStream with the provided KeyValueMapper The provided KeyValueMapper's mapped value type must be String.
Printed<K,V>	withLabel(java.lang.String label)	Print the records of a KStream with the provided label.

Methods inherited from class java.lang.Object

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

Field Detail

printWriter

protected final java.io.PrintWriter printWriter

label

protected java.lang.String label

mapper

protected KeyValueMapper<? super K,? super V,java.lang.String> mapper

Constructor Detail

Printed

protected Printed(Printed<K,V> printed)

Copy constructor.

Parameters:

printed - instance of Printed to copy

Method Detail

toFile

public static <K,V> Printed<K,V> toFile(java.lang.String filePath)

Print the records of a KStream to a file.

Type Parameters:

K - key type

V - value type

Parameters:

filePath - path of the file

Returns:

a new Printed instance

toSysOut

public static <K,V> Printed<K,V> toSysOut()

Print the records of a KStream to system out.

Type Parameters:

K - key type

V - value type

Returns:

a new Printed instance

withLabel

public Printed<K,V> withLabel(java.lang.String label)

Print the records of a KStream with the provided label.

Parameters:

label - label to use

Returns:

this

withKeyValueMapper

public Printed<K,V> withKeyValueMapper(KeyValueMapper<? super K,? super V,java.lang.String> mapper)

Print the records of a KStream with the provided KeyValueMapper The provided KeyValueMapper's mapped value type must be String.

The example below shows how to customize output data.

 final KeyValueMapper<Integer, String, String> mapper = new KeyValueMapper<Integer, String, String>() {
     public String apply(Integer key, String value) {
         return String.format("(%d, %s)", key, value);
     }
 };
 

Implementors will need to override toString() for keys and values that are not of type String, Integer etc. to get meaningful information.

Parameters:

mapper - mapper to use

Returns:

this