Package org.springframework.kafka.support

Class SimpleKafkaHeaderMapper

java.lang.Object

org.springframework.kafka.support.AbstractKafkaHeaderMapper

org.springframework.kafka.support.SimpleKafkaHeaderMapper

All Implemented Interfaces:

KafkaHeaderMapper

public class SimpleKafkaHeaderMapper
extends AbstractKafkaHeaderMapper

A simple header mapper that maps headers directly; for outbound, only byte[] headers are mapped; for inbound, headers are mapped unchanged, as byte[]. Strings can also be mapped to/from byte. See AbstractKafkaHeaderMapper.setRawMappedHeaders(Map). Most headers in KafkaHeaders are not mapped on outbound messages. The exceptions are correlation and reply headers for request/reply

Since:

2.1.3

Author:

Gary Russell

Nested Class Summary

Nested classes/interfaces inherited from class org.springframework.kafka.support.AbstractKafkaHeaderMapper

AbstractKafkaHeaderMapper.HeaderMatcher, AbstractKafkaHeaderMapper.NeverMatchHeaderMatcher, AbstractKafkaHeaderMapper.SimplePatternBasedHeaderMatcher

Field Summary

Fields inherited from class org.springframework.kafka.support.AbstractKafkaHeaderMapper

logger

Constructor Summary

Constructors

Constructor	Description
SimpleKafkaHeaderMapper()	Construct an instance with the default object mapper and default header patterns for outbound headers; all inbound headers are mapped.
SimpleKafkaHeaderMapper(String... patterns)	Construct an instance with a default object mapper and the provided header patterns for outbound headers; all inbound headers are mapped.

Method Summary

Modifier and Type	Method	Description
static SimpleKafkaHeaderMapper	forInboundOnlyWithMatchers(String... patterns)	Create an instance for inbound mapping only with pattern matching.
void	fromHeaders(MessageHeaders headers, org.apache.kafka.common.header.Headers target)	Map from the given MessageHeaders to the specified target headers.
void	toHeaders(org.apache.kafka.common.header.Headers source, Map<String,Object> target)	Map from the given native headers to a map of headers for the eventual MessageHeaders.

Methods inherited from class org.springframework.kafka.support.AbstractKafkaHeaderMapper

addMatchers, addRawMappedHeader, getCharset, headerValueToAddIn, headerValueToAddOut, matches, matches, matchesForInbound, setCharset, setMapAllStringsOut, setRawMappedHeaders

Methods inherited from class java.lang.Object

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

Constructor Details

SimpleKafkaHeaderMapper

public SimpleKafkaHeaderMapper()

Construct an instance with the default object mapper and default header patterns for outbound headers; all inbound headers are mapped. The default pattern list is "!id", "!timestamp" and "*". In addition, most of the headers in KafkaHeaders are never mapped as headers since they represent data in consumer/producer records.

SimpleKafkaHeaderMapper

public SimpleKafkaHeaderMapper(String... patterns)

Construct an instance with a default object mapper and the provided header patterns for outbound headers; all inbound headers are mapped. The patterns are applied in order, stopping on the first match (positive or negative). Patterns are negated by preceding them with "!". The patterns will replace the default patterns; you generally should not map the "id" and "timestamp" headers. Note: most of the headers in KafkaHeaders are never mapped as headers since they represent data in consumer/producer records.

Parameters:

patterns - the patterns.

See Also:

• PatternMatchUtils.simpleMatch(String, String)

Method Details

forInboundOnlyWithMatchers

public static SimpleKafkaHeaderMapper forInboundOnlyWithMatchers(String... patterns)

Create an instance for inbound mapping only with pattern matching.

Parameters:

patterns - the patterns to match.

Returns:

the header mapper.

Since:

2.8.8

fromHeaders

public void fromHeaders(MessageHeaders headers,
 org.apache.kafka.common.header.Headers target)

Description copied from interface: KafkaHeaderMapper

Map from the given MessageHeaders to the specified target headers.

Parameters:

headers - the abstracted MessageHeaders.

target - the native target headers.

toHeaders

public void toHeaders(org.apache.kafka.common.header.Headers source,
 Map<String,Object> target)

Description copied from interface: KafkaHeaderMapper

Map from the given native headers to a map of headers for the eventual MessageHeaders.

Parameters:

source - the native headers.

target - the target headers.