Package org.springframework.cloud.stream.binder

Class EmbeddedHeaderUtils

java.lang.Object

org.springframework.cloud.stream.binder.EmbeddedHeaderUtils

public abstract class EmbeddedHeaderUtils
extends Object

Encodes requested headers into payload with format 0xff, n(1), [ [lenHdr(1), hdr, lenValue(4), value] ... ]. The 0xff indicates this new format; n is number of headers (max 255); for each header, the name length (1 byte) is followed by the name, followed by the value length (int) followed by the value (json).

Previously, there was no leading 0xff; the value length was 1 byte and only String header values were supported (no JSON conversion).

Since:

1.2

Author:

Eric Bottard, Gary Russell, Ilayaperumal Gopinathan, Marius Bogoevici

Constructor Summary

Constructors

Constructor	Description
EmbeddedHeaderUtils()

Method Summary

Modifier and Type	Method	Description
static String	decodeExceptionMessage(org.springframework.messaging.Message<?> requestMessage)
static byte[]	embedHeaders(MessageValues original, String... headers)	Return a new message where some of the original headers of original have been embedded into the new message payload.
static MessageValues	extractHeaders(byte[] payload)	Return a message where headers, that were originally embedded into the payload, have been promoted back to actual headers.
static MessageValues	extractHeaders(org.springframework.messaging.Message<byte[]> message, boolean copyRequestHeaders)	Return a message where headers, that were originally embedded into the payload, have been promoted back to actual headers.
static String[]	headersToEmbed(String[] configuredHeaders)
static boolean	mayHaveEmbeddedHeaders(byte[] bytes)	Return true if the bytes might have embedded headers.

Methods inherited from class java.lang.Object

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

Constructor Detail

EmbeddedHeaderUtils

public EmbeddedHeaderUtils()

Method Detail

decodeExceptionMessage

public static String decodeExceptionMessage(org.springframework.messaging.Message<?> requestMessage)

embedHeaders

public static byte[] embedHeaders(MessageValues original,
                                  String... headers)

Return a new message where some of the original headers of original have been embedded into the new message payload.

Parameters:

original - original message

headers - headers to embedd

Returns:

a new message

extractHeaders

public static MessageValues extractHeaders(org.springframework.messaging.Message<byte[]> message,
                                           boolean copyRequestHeaders)
                                    throws Exception

Return a message where headers, that were originally embedded into the payload, have been promoted back to actual headers. The new payload is now the original payload.

Parameters:

message - the message to extract headers

copyRequestHeaders - boolean value to specify if the request headers should be copied

Returns:

wrapped message values

Throws:

Exception - when extraction failed

extractHeaders

public static MessageValues extractHeaders(byte[] payload)
                                    throws Exception

Return a message where headers, that were originally embedded into the payload, have been promoted back to actual headers. The new payload is now the original payload.

Parameters:

payload - the message payload

Returns:

the message with extracted headers

Throws:

Exception - when extraction failed

headersToEmbed

public static String[] headersToEmbed(String[] configuredHeaders)

mayHaveEmbeddedHeaders

public static boolean mayHaveEmbeddedHeaders(byte[] bytes)

Return true if the bytes might have embedded headers. (First byte is 0xff and long enough for at least one header).

Parameters:

bytes - the array.

Returns:

true if it may have embedded headers.