Eclipse Community Forums: OM2M » CoAP blockwise transfer

Home » Eclipse Projects » OM2M » CoAP blockwise transfer(Californium 0.18.6 does not handle blockwise transfer correctly)

Show: Today's Messages :: Show Polls :: Message Navigator

CoAP blockwise transfer [message #1764508]

Tue, 30 May 2017 15:55

Regis DARGENT

Messages: 3
Registered: November 2016

Junior Member

Hi everybody,
I recently fell on a problem using OneM2M server and CoAP protocol :
When the payload is too high, we have to split the frame into several blocks (CoAP blockwise transfer) ;
The Californium CoAP stack of OneM2M server should then re-assemble the different blocks, but I can see in the logs that it is not done correctly : the headers are lost in the process, so the data is dropped.

I successfully ported the last stable version of californium (1.0.5) to OneM2M :

I changed "californium-0.18.6-final.jar" to "californium-core-1.0.5.jar"
and "element-connector-0.2-final.jar" to "element-connector-1.0.5.jar"
in the 3 files:
org.eclipse.om2m.binding.coap/META-INF/MANIFEST.MF
org.eclipse.om2m.binding.coap/.classpath
org.eclipse.om2m.binding.coap/build.properties

I then modified the attached .java files (I mainly changed the 'import' lines, and changed the name of the CoapServer class to Om2mCoapServerClass, as the previous name is now used in Californium).

I it may be usefull to someone...

Attachment: CoapClient.java
(Size: 11.93KB, Downloaded 109 times)
Attachment: Om2mCoapServer.java
(Size: 15.68KB, Downloaded 102 times)
Attachment: Activator.java
(Size: 3.15KB, Downloaded 89 times)