Dynamic URL for Custom Http-Client - Spring-XD - spring

Question

We have written a custom Http-client for spring XD and planning to use this custom processor for invoking different APIs. However, We have a situation where we need to invoke two different API based on the payload. Apart from using dynamic-router (which writes to a named channel) is there a way we can set the URL dynamically for the http-client to invoke? Here is the current configuration.
<header-filter input-channel="input" output-channel="inputX"
header-names="x-death" />
<service-activator input-channel="inputX" ref="gw" />
<gateway id="gw" default-request-channel="toHttp"
default-reply-timeout="0" error-channel="errors" />
<beans:bean id="inputfields"
class="com.batch.httpclient.HTTPInputProperties">
<beans:property name="nonRetryErrorCodes" value="${nonRetryErrorCodes}" />
</beans:bean>
<beans:bean id="responseInterceptor"
class="com.batch.httpclient.ResponseInterceptor">
<beans:property name="inputProperties" ref="inputfields" />
</beans:bean>
<chain input-channel="errors" output-channel="output">
<transformer ref="responseInterceptor" />
</chain>
<int-http:outbound-gateway id='batch-http'
header-mapper="headerMapper" request-channel='toHttp' url-expression="${url}"
http-method="${httpMethod}" expected-response-type='java.lang.String'
charset='${charset}' reply-timeout='${replyTimeout}' reply-channel='output'>
</int-http:outbound-gateway>
<beans:bean id="headerMapper"
class="org.springframework.integration.http.support.DefaultHttpHeaderMapper"
factory-method="outboundMapper">
<beans:property name="outboundHeaderNames" value="*" />
<beans:property name="userDefinedHeaderPrefix" value="" />
</beans:bean>
<channel id="output" />
<channel id="input" />
<channel id="inputX" />
<channel id="toHttp" />

Answer 1

If it's based on the payload type, something like this should work...
url-expression="payload.getClass().getSimpleName().equals("Bar") ? 'http://foo/bar' : 'http://foo/baz'"
If it's a property on the payload, then
url-expression="payload.foo.equals("bar") ? 'http://foo/bar' : 'http://foo/baz'"
EDIT
or
url-expression="payload.foo.equals("bar") ? '${url1}' : '${url2}'"
This would need changing the property metadata class to rename url and add url2.