org.springframework.messaging.simp.stomp

Class StompDecoder

java.lang.Object

org.springframework.messaging.simp.stomp.StompDecoder

public class StompDecoder
extends Object

Decodes one or more STOMP frames contained in a ByteBuffer.

An attempt is made to read all complete STOMP frames from the buffer, which could be zero, one, or more. If there is any left-over content, i.e. an incomplete STOMP frame, at the end the buffer is reset to point to the beginning of the partial content. The caller is then responsible for dealing with that incomplete content by buffering until there is more input available.

Since:

4.0

Author:

Andy Wilkinson, Rossen Stoyanchev

Constructor Summary

Constructors

Constructor and Description
StompDecoder()

Method Summary

Modifier and Type	Method and Description
List<Message<byte[]>>	decode(ByteBuffer byteBuffer) Decodes one or more STOMP frames from the given ByteBuffer into a list of Messages.
List<Message<byte[]>>	decode(ByteBuffer byteBuffer, MultiValueMap<String,String> partialMessageHeaders) Decodes one or more STOMP frames from the given buffer and returns a list of Messages.
MessageHeaderInitializer	getHeaderInitializer() Return the configured MessageHeaderInitializer, if any.
void	setHeaderInitializer(MessageHeaderInitializer headerInitializer) Configure a MessageHeaderInitializer to apply to the headers of Messages from decoded STOMP frames.
protected void	skipEol(ByteBuffer byteBuffer) Skip one ore more EOL characters at the start of the given ByteBuffer.

Methods inherited from class java.lang.Object

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

Constructor Detail

StompDecoder

public StompDecoder()

Method Detail

setHeaderInitializer

public void setHeaderInitializer(@Nullable
                                 MessageHeaderInitializer headerInitializer)

Configure a MessageHeaderInitializer to apply to the headers of Messages from decoded STOMP frames.

getHeaderInitializer

@Nullable
public MessageHeaderInitializer getHeaderInitializer()

Return the configured MessageHeaderInitializer, if any.

decode

public List<Message<byte[]>> decode(ByteBuffer byteBuffer)

Decodes one or more STOMP frames from the given ByteBuffer into a list of Messages. If the input buffer contains partial STOMP frame content, or additional content with a partial STOMP frame, the buffer is reset and null is returned.

Parameters:

byteBuffer - the buffer to decode the STOMP frame from

Returns:

the decoded messages, or an empty list if none

Throws:

StompConversionException - raised in case of decoding issues

decode

public List<Message<byte[]>> decode(ByteBuffer byteBuffer,
                                    @Nullable
                                    MultiValueMap<String,String> partialMessageHeaders)

Decodes one or more STOMP frames from the given buffer and returns a list of Messages.

If the given ByteBuffer contains only partial STOMP frame content and no complete STOMP frames, an empty list is returned, and the buffer is reset to to where it was.

If the buffer contains one ore more STOMP frames, those are returned and the buffer reset to point to the beginning of the unused partial content.

The output partialMessageHeaders map is used to store successfully parsed headers in case of partial content. The caller can then check if a "content-length" header was read, which helps to determine how much more content is needed before the next attempt to decode.

Parameters:

byteBuffer - the buffer to decode the STOMP frame from

partialMessageHeaders - an empty output map that will store the last successfully parsed partialMessageHeaders in case of partial message content in cases where the partial buffer ended with a partial STOMP frame

Returns:

the decoded messages, or an empty list if none

Throws:

StompConversionException - raised in case of decoding issues

skipEol

protected void skipEol(ByteBuffer byteBuffer)

Skip one ore more EOL characters at the start of the given ByteBuffer. STOMP, section 2.1 says: "The NULL octet can be optionally followed by multiple EOLs."