Payload Enricher doesnot work when palyload is empty.

[oleg.zhurakousky]

Also, in the code that I posted I am modifying the actual Map to sort of fit what you were trying to do initially. However you can produce a whole different payload type. Basically whatever you return from that method is going to be a new Message payload and in your case I would recommend that since you really don't want to depend on some Spring specific class (e.g., LinkedMultiValueMap). So you can create a new HashMap (if you stil need a Map) or something completely different. . .

[Cleric]

Hello, folks!
I've just reproduced it:

@Test
	public void testMultiValueMap() {
		QueueChannel replyChannel = new QueueChannel();
		DirectChannel requestChannel = new DirectChannel();
		requestChannel.subscribe(new AbstractReplyProducingMessageHandler() {
			@Override
			protected Object handleRequestMessage(Message<?> requestMessage) {
				return new Source("John", "Doe");
			}
		});
		ContentEnricher enricher = new ContentEnricher();
		enricher.setRequestChannel(requestChannel);

		SpelExpressionParser parser = new SpelExpressionParser();
		Map<String, Expression> propertyExpressions = new HashMap<String, Expression>();
		propertyExpressions.put("name", parser.parseExpression("payload.lastName + ', ' + payload.firstName"));
		enricher.setPropertyExpressions(propertyExpressions);
		enricher.afterPropertiesSet();

		Message<?> requestMessage = MessageBuilder.withPayload(new LinkedMultiValueMap()).setReplyChannel(replyChannel).build();
		enricher.handleMessage(requestMessage);
		Message<?> reply = replyChannel.receive(0);
		MultiValueMap result = (MultiValueMap) reply.getPayload();
		assertEquals("test", result.get("name"));
	}

The problem is really laying on MultiValueMap. It requeries that the value should be java.util.List.
The simple fix of it - just wrap the expression with {}:

<int:enricher id="deletePaymentInstrumentEnricher" input-channel="deletePayloadEnricher" >
<introperty name="paymentInstrumentToken" value="{onewerewrwerwe}" />
</int:enricher> 

So, there is no any reason to open new JIRA.

Best regards,
Artem Bilan

[oleg.zhurakousky]

Right! I totally forgot abou that as well as us using MapAccessor which allows treating key/value as properties on both read and write.
So thanks Artem!

[Cleric]

Sorry, I explain a bit my post:
1. {} is an inline List: http://static.springsource.org/sprin....html#d0e12704
2. You also can use on your <http:inbound-gateway> this one:

<http:inbound-gateway
	payload-expression="requestParams.toSingleValueMap()"/>

3. Or use the same method in the 'expression' of simple <transformer> before <enricher>

Hope I'm clear