content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.camel.coap;
  
  import java.io.IOException;
  
  import org.apache.camel.Exchange;
  import org.apache.camel.Processor;
  import org.apache.camel.support.DefaultConsumer;
  import org.eclipse.californium.core.CoapClient;
  import org.eclipse.californium.core.CoapHandler;
  import org.eclipse.californium.core.CoapResponse;
  
  /**
   * The CoAP observer.
   */
  public class CoAPObserver extends DefaultConsumer implements CoapHandler {
      private final CoAPEndpoint endpoint;
      private CoapClient client;
  
      public CoAPObserver(final CoAPEndpoint endpoint, final Processor processor) {
          super(endpoint, processor);
          this.endpoint = endpoint;
      }
  
      @Override
      protected void doStart() throws Exception {
          super.doStart();
          if (this.client == null) {
              client = endpoint.createCoapClient(endpoint.getUri());
          }
          startObserve();
      }
  
      @Override
      public void onLoad(CoapResponse response) {
          Exchange camelExchange = createExchange(false);
          try {
              CoAPHelper.convertCoapResponseToMessage(response, camelExchange.getMessage());
              getProcessor().process(camelExchange);
          } catch (Exception e) {
              camelExchange.setException(e);
          } finally {
              Exception exception = camelExchange.getException();
              if (exception != null) {
                  getExceptionHandler().handleException("Error processing observed update", camelExchange, exception);
              }
              releaseExchange(camelExchange, false);
          }
      }
  
      @Override
      public void onError() {
          getExceptionHandler().handleException(new IOException("CoAP request timed out or has been rejected by the server"));
          startObserve();
      }
  
      private void startObserve() {
          this.client.observe(this);
      }
  }
  