Californium Framework CoAP and PUT request - eclipse

Question

I am trying to do a request to coap server (er-rest-example) using Californium.
I succesfully do a POST request.
But with PUT I am getting a BAD REQUEST, I try using this URLs in url:
coap://[aaaa::c30c:0000:0000:0002]:5683/actuators/leds
coap://[aaaa::c30c:0000:0000:0002]:5683/actuators/leds?
coap://[aaaa::c30c:0000:0000:0002]:5683/actuators/leds?color=r
But with no one get success.
What I am doing wrong?.
This is my simple script:
package coap_client;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.Arrays;
import java.util.Timer;
import java.util.TimerTask;
import org.eclipse.californium.core.CoapClient;
import org.eclipse.californium.core.CoapResponse;
import org.eclipse.californium.core.coap.MediaTypeRegistry;
public class cliente {
public static void main(String[] args) throws Exception {
Timer timer;
timer = new Timer();
TimerTask task = new TimerTask(){
#Override
public void run(){
String url="coap://[aaaa::c30c:0000:0000:0002]:5683/actuators/leds";
URI uri= null;
try {
uri = new URI(url);
} catch (URISyntaxException e) {
e.printStackTrace();
}
CoapClient client = new CoapClient(uri);
CoapResponse response = client.put("color=r",MediaTypeRegistry.TEXT_PLAIN);
System.out.println(response.isSuccess());
if (response!=null) {
byte[] myreponse=response.getPayload();
String respuesta2 = new String(myreponse);
System.out.println(respuesta2);
}
}
};
timer.schedule(task, 10,10*1000);
}
}

Answer 1

In Contiki er-rest-example, see the POST/PUT handler(1) for the LED CoAP resource. It expects a mode param without which you will get a BAD_REQUEST as response. I assume that has to go in the request body.