http pass through to a REST service

[iwright]

I'm probably missing something obvious here but I can't see it and it's my first attempt at using Spring Integration.

What I want to do is to receive an HTTP GET request, send it to a REST service and return the response.

I've got the request being handed off the service working fine.

The part that I can't get working is to return the response body - I've set the expected-response-type to java.lang.String but nothing is coming back (The response is XML)

Config below.


<bean class="org.springframework.web.servlet.handler.Sim pleUrlHandlerMapping">
<property name="mappings">
<props>
<prop key="files">httpInbound</prop>
</props>
</property>
</bean>

<int-http:inbound-gateway id="httpInbound"
reply-timeout="10000"
request-channel="httpRequestChannel"
reply-channel="httpReplyChannel"
mapped-request-headers="HTTP_REQUEST_HEADERS, X-*"
mapped-response-headers="HTTP_RESPONSE_HEADERS, X-*"
extract-reply-payload="true"

/>

<int-http:outbound-gateway id="httpOutbound"
request-channel="httpRequestChannel"
url="http://localhost:8080/myService/service/action"
charset="UTF-8"
reply-channel="httpReplyChannel"
http-method="GET"
expected-response-type="java.lang.String"
mapped-request-headers="HTTP_REQUEST_HEADERS, X-*"
mapped-response-headers="HTTP_RESPONSE_HEADERS, X-*">
</int-http:outbound-gateway>

<int:channel id="httpReplyChannel"/>

[Gary Russell]

Can you zip and post a log with the org.springframework.integration logger set to DEBUG?

[iwright]

Hi,
Here is the log file

Thanks,
Ian

[Gary Russell]

Everything looks fine to me...

...postSend (sent=true) on channel 'httpReplyChannel', message: [Payload=<?xml version=...

What are you seeing on your client?

[iwright]

There is no data coming back from the server, however the (partial) header is as follows:

< Content-Type: text/plain;charset=ISO-8859-1
< Content-Length: 161
<

Some further info:
I've got 3 services I'm trying to call like this and having tried a different one it works... - a bit more investigation shows that when I call these services directly the ones that don't work have the following header:
< Server: Apache-Coyote/1.1
< Content-Type: application/xml
< Transfer-Encoding: chunked

The one that does work has:
< Server: Apache-Coyote/1.1
< Content-Type: application/xml;charset=ISO-8859-1
< Content-Language: en-GB
< Content-Length: 3055938



Thanks.

[Gary Russell]

I see you removed the comment about the bridge - it is an internal bridge to bridge from your httpReplyChannel to the channel in the message's replyChannel header.

I believe the problem is the transfer-encoding header is being copied and confusing the client. From the log where the output message is being built...

setting headerName=[Transfer-Encoding], value=chunked

You should be able to remove this header with a filter...

<header-filter input-channel="httpReplyChannel" output-channel="filteredHttpReplyChannel"
    header-names="Transfer-Encoding" />

and change your input gateway's reply-channel to 'filteredHttpReplyChannel".

We should probably not map that header on output; please open a JIRA issue.

[simonso]

Any plans for fixing this?

https://jira.springsource.org/browse/INT-2524

Minor but annoying... Everywhere in the code I either have to put the filter tag or remove the header with java code...

[Mark Fisher]

We are going to address it for 2.2. Thanks for drawing our attention to it again.

-Mark

[simonso]

Thanks so much!

Really looking forward to 2.2 - using 2.2 M4 already - I love the int:chain which supports embedding http:outbound-gateway!