CODEWITHSUNDEEP
spring-integrationmqttspring-xd
peez80
peez80

Reputation: 1643

SpringXD receive MQTT and publish to MQTT on different topic

I'm currently working on my first SpringXD Stream. It should receive a message on an MQTT topic, do a HTTP POST on a service and publish this result on another MQTT topic.

Currently I'm stuck at publishing to a different MQTT topic than the initial one.

This is my stream:

stream create test --definition "in:mqtt --url='tcp://hivemq:1883' --topics='+/+/+/my/downlink' --username='test' --password='test' --clientId='client_downlink' 
| header-enricher --headers={\"mqtt_topic\":\"headers['mqtt_topic'].replace('/downlink', '/uplink')\"} 
| out:mqtt --url='tcp://hivemq:1883' --username='test' --password='test' --clientId='client_uplink'" --deploy

The approach is to replace "/downlink" by "/uplink" in the header 'mqtt_topic' for Publishing but header-enricher doesn't overwrite existing header values, so the publish is made on the same topic as we received the message.

Any Idea how I could achieve this?

Upvotes: 1

Views: 129

Answers (1)

dturanski
dturanski

Reputation: 1723

I am working on an enhancement for this. Meanwhile you can edit the header-enricher groovy script modules/processor/header-enricher/config/header-enricher.groovy and make this change:

si.'header'(name:k,expression:v,overwrite:true)

Upvotes: 3

Related Questions