Reading an ActiveMQ Topic using cURL - Getting message bodies

Question

I'm trying to debug some JMS code by running an ActiveMQ locally - Using the Docker image rmohr/activemq:5.15.4-alpine - and using cURL to read the messages posted to the topic. This is mostly working, but I'm not getting the actual body of the message.

What I'm doing is:

curl -v -XGET http://admin:admin@localhost:8161/api/message?destination=topic://Events&json=true&oneShot=true

And this works as follows:

> GET /api/message?destination=topic://Events&json=true&oneShot=true HTTP/1.1
> Host: localhost:8161
> Authorization: Basic YWRtaW46YWRtaW4=
> User-Agent: curl/7.54.0
> Accept: */*
>

< HTTP/1.1 200 OK
< Date: Tue, 20 Nov 2018 17:09:03 GMT
< X-FRAME-OPTIONS: SAMEORIGIN
< Set-Cookie: JSESSIONID=mcjaka6dsuz6534j0gj0gfnv;Path=/api
< Expires: Thu, 01 Jan 1970 00:00:00 GMT
< Cache-Control: no-cache, no-store, must-revalidate
< Pragma: no-cache
< Content-Type: application/x-www-form-urlencoded; charset=ISO-8859-1
< destination: topic://Events
< id: ID:b8b750274409-46243-1542707161912-1:23:1:1:6
< eventTime$iso8601: 2018-11-20T17:09:13.216Z
< eventTime$millis: 1542733753216
< eventName: ProcessItemEvent
< Transfer-Encoding: chunked
< Server: Jetty(9.2.22.v20170606)
<

However, the actual payload of the message is not returned. If I take off the json=true&oneShot=true then I get this instead:

{ [5 bytes data]

But still no more than that. And there should be a lot more than 5 bytes of payload data for these messages.

What am I missing in getting these messages to come through correctly?

Cheers

Answer 1

You are subscribing to topic://Events . Could it be that all the event information is in the header of the http response, and ActiveMQ is not adding anything extra in the body?

< destination: topic://Events
< id: ID:b8b750274409-46243-1542707161912-1:23:1:1:6
< eventTime$iso8601: 2018-11-20T17:09:13.216Z
< eventTime$millis: 1542733753216
< eventName: ProcessItemEven

If you want the messages posted to a specific topic, say 'foo.bar' you need to subscribe to topic://foo.bar .

Answer 2

I tried your command. As you can see below, I am getting the message body.

Could it be that you are receiving binary data that is not displaying in the terminal? Can you try saving the message body to a file. e.g. curl -o body.dat -v -XGET ...

$ curl -v -XGET 'http://admin:admin@localhost:8161/api/message?destination=topic://bayCarrState'
> GET /api/message?destination=topic://bayCarrState HTTP/1.1
> Authorization: Basic YWRtaW46YnJva2VyYWRtaW4=
> User-Agent: curl/7.29.0
> Host: localhost:8161
> Accept: */*
> 
< HTTP/1.1 200 OK
< Date: Fri, 23 Nov 2018 04:55:59 GMT
< X-FRAME-OPTIONS: SAMEORIGIN
< Set-Cookie: JSESSIONID=sbwv48hmp5w9zw4zgttrbmyn;Path=/api
< Expires: Thu, 01 Jan 1970 00:00:00 GMT
< Cache-Control: no-cache, no-store, must-revalidate
< Pragma: no-cache
< Content-Type: text/plain; charset=ISO-8859-1
< destination: topic://bayCarrState
< id: ID:prd-rh7.mirrabooka.local-40596-1541746708502-3:160:-1:1:105
< Transfer-Encoding: chunked
< Server: Jetty(9.2.22.v20170606)
< 
[{"elemId":"BayCarrState1","elemType":"BayCarrState","elemValue":{"bayId":"1","binFullWt":0,"binTipng":0,"binUntipdWt":0,"continuableRailSam
":0,"delivType":"R","frontPos":14,"lastSamTipng":0,"lastTickTipng":0,"locNum":1,"milltrainId":"A","rearPos":1,"samInProgress":0,"samTipng":0
,"tickTipng":0,"tipInProgress":0,"tipReady":0},"version":294},{"elemId":"BayCarrState2","elemType":"BayCarrState","elemValue":{"bayId":"2","
binFullWt":0,"binTipng":0,"binUntipdWt":0,"continuableRailSam":0,"delivType":"T","frontPos":28,"lastSamTipng":0,"lastTickTipng":0,"locNum":1
,"milltrainId":"A","rearPos":15,"samInProgress":0,"samTipng":0,"tickTipng":0,"tipInProgress":0,"tipReady":0},"version":294}]
* Connection #0 to host localhost left intact