Question about MessageHeaders.REPLY_CHANNEL.endsWith(headerName) usage in MessageHeaderAccessor#verifyType

[NineSu]

Hi Spring team,

While reading the source code of org.springframework.messaging.support.MessageHeaderAccessor, I noticed something that seems potentially unintended in the verifyType method:

protected void verifyType(@Nullable String headerName, @Nullable Object headerValue) {
	if (headerName != null && headerValue != null) {
		if (MessageHeaders.ERROR_CHANNEL.equals(headerName) ||
				MessageHeaders.REPLY_CHANNEL.endsWith(headerName)) {
			if (!(headerValue instanceof MessageChannel || headerValue instanceof String)) {
				throw new IllegalArgumentException(
						"'" + headerName + "' header value must be a MessageChannel or String");
			}
		}
	}
}

My question is about the use of MessageHeaders.REPLY_CHANNEL.endsWith(headerName) — is this intended to be endsWith, or should it be equals, similar to how ERROR_CHANNEL is compared? Using endsWith might lead to false positives when the header name is a suffix of "replyChannel".

Could you please clarify if this is intentional or if it might be a bug?

Thanks for your great work!

[NineSu]

@rstoyanchev

[rstoyanchev]

Thanks for spotting this very old issue that can be traced all the way back to commit 059aef in Spring Integration. It appears to be an oversight as it would only apply to header names that are a subset of "replyChannel", and that doesn't make much sense.

[rstoyanchev]

Superseded by #34949.