public void onLoad(CoapResponse coapResponse) {
    String payloadString = coapResponse.advanced().getPayloadString();
    String source1 = coapResponse.advanced().getSource().getCanonicalHostName();
    String source2 = coapResponse.advanced().getSource().getHostName();
    String source3 = coapResponse.advanced().getSource().getHostAddress();

    System.out.print(
        "Observable Response: "
            + payloadString
            + ", Source 1: "
            + source1
            + ", Source 2: "
            + source2
            + ", Source3: "
            + source3
            + "\n");
  }