Class KafkaMessageHeaderAccessor

java.lang.Object

org.springframework.messaging.support.MessageHeaderAccessor

org.springframework.kafka.support.KafkaMessageHeaderAccessor

public class KafkaMessageHeaderAccessor
extends MessageHeaderAccessor

A header accessor to provide convenient access to certain headers in a type specific manner.

Since:

3.0.10

Author:

Gary Russell

Field Summary

Fields inherited from class org.springframework.messaging.support.MessageHeaderAccessor

DEFAULT_CHARSET

Constructor Summary

Constructors

Constructor	Description
KafkaMessageHeaderAccessor(Message<?> message)	Construct an instance for the provided message.

Method Summary

Modifier and Type	Method	Description
protected MessageHeaderAccessor	createAccessor(Message<?> message)
int	getBlockingRetryDeliveryAttempt()	Access the header value when the blocking delivery attempt header is present.
<T> @Nullable T	getHeader(String key, Class<T> type)	Get a header value with a specific type.
int	getNonBlockingRetryDeliveryAttempt()	When using non-blocking retries, get the delivery attempt header value as an int.
static KafkaMessageHeaderAccessor	wrap(Message<?> message)	Create an instance from the payload and headers of the given Message.

Methods inherited from class org.springframework.messaging.support.MessageHeaderAccessor

copyHeaders, copyHeadersIfAbsent, fromMap, fromMessageHeaders, getAccessor, getAccessor, getAccessor, getContentType, getDetailedLogMessage, getDetailedPayloadLogMessage, getErrorChannel, getHeader, getId, getMessageHeaders, getMutableAccessor, getReplyChannel, getShortLogMessage, getShortPayloadLogMessage, getTimestamp, isModified, isMutable, isReadableContentType, isReadOnly, removeHeader, removeHeaders, setContentType, setErrorChannel, setErrorChannelName, setHeader, setHeaderIfAbsent, setImmutable, setLeaveMutable, setModified, setReplyChannel, setReplyChannelName, toMap, toMessageHeaders, toString, verifyType

Methods inherited from class java.lang.Object

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

Constructor Details

KafkaMessageHeaderAccessor

public KafkaMessageHeaderAccessor(Message<?> message)

Construct an instance for the provided message.

Parameters:

message - the message.

Method Details

getBlockingRetryDeliveryAttempt

public int getBlockingRetryDeliveryAttempt()

Access the header value when the blocking delivery attempt header is present.

Returns:

The decoded header value if the header is present.

Throws:

IllegalStateException - if the header is not present.

See Also:

• ContainerProperties.setDeliveryAttemptHeader(boolean)

getNonBlockingRetryDeliveryAttempt

public int getNonBlockingRetryDeliveryAttempt()

When using non-blocking retries, get the delivery attempt header value as an int.

Returns:

1 if there is no header present; the decoded header value otherwise.

getHeader

public <T> @Nullable T getHeader(String key,
 Class<T> type)

Get a header value with a specific type.

Type Parameters:

T - the type.

Parameters:

key - the header name.

type - the type's Class.

Returns:

the value, if present.

Throws:

IllegalArgumentException - if the type is not correct.

createAccessor

protected MessageHeaderAccessor createAccessor(Message<?> message)

Overrides:

createAccessor in class MessageHeaderAccessor

wrap

public static KafkaMessageHeaderAccessor wrap(Message<?> message)

Create an instance from the payload and headers of the given Message.

Parameters:

message - the message.

Returns:

the accessor.