openstack-neutron/src/main/java/org/jclouds/openstack/neutron/v2/fallbacks/EmptySecurityGroupsFallback.java

/*
 * 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.jclouds.openstack.neutron.v2.fallbacks;

import com.google.common.util.concurrent.ListenableFuture;
import org.jclouds.Fallback;
import org.jclouds.openstack.neutron.v2.domain.SecurityGroups;
import org.jclouds.rest.ResourceNotFoundException;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Throwables.propagate;
import static com.google.common.util.concurrent.Futures.immediateFuture;
import static org.jclouds.http.HttpUtils.contains404;
import static org.jclouds.util.Throwables2.getFirstThrowableOfType;

public class EmptySecurityGroupsFallback implements Fallback<SecurityGroups> {

   public ListenableFuture<SecurityGroups> create(Throwable t) throws Exception {
      return immediateFuture(createOrPropagate(t));
   }

   @Override
   public SecurityGroups createOrPropagate(Throwable t) throws Exception {
      if ((getFirstThrowableOfType(checkNotNull(t, "throwable"), ResourceNotFoundException.class) != null)
            || contains404(t)) {
         return SecurityGroups.EMPTY;
      }
      throw propagate(t);
   }
}