I'm trying to read the Weblinks from the CoAP endpoint /.well-known/core using the Californium CoapClient.discover(). The discover method returns the Weblinks all the time without any reported errors during execution. But the problem is with the number of weblinks it will return, e.g, If the expected weblink count is 240 Weblinks, the method return a random number of weblinks like 80, 125, 160 and this varies each time. Sometimes the weblinks discovered is 240 and it is not deterministic. I'm using the default properties to connect with the device.
CoapClient client = new CoapClient("coap://" + deviceIpAddress + ":" + port);
Set<WebLink> links = client.discover();
I have also tried using the CoapClient.get() instead of using discover() and the result is same when using get().
CoapClient client = new CoapClient("coap://" + deviceIpAddress + ":" + port+"/.well-known/core");
CoapResponse response = client.get();
This error is observed if the response size is bigger(weblink count is >42), in this test the response size is 8Kb(Weblink count=240). If the response weblink count is <42 the Weblinks reading is always as expected.
I have also tried some of the options PREFERRED_BLOCK_SIZE, MAX_MESSAGE_SIZE, MAX_RESOURCE_BODY_SIZE provided by the californium library but the result is the same.
I'm using the Californium library version 3.8.0 and observed this behavior with an old version 2.4.1(my application was using this old version when we have noticed this issue, and later on upgraded to latest version 3.8.0).
I have also tried get on /.well-known/core using the Copper Plugin for Firefox. This works without any issue.
Can someone suggest if I'm doing anything incorrectly here or do I need to use any additional properties to read the data correctly.