org.jclouds.openstack.marconi.v1.domain.MessageStream.java Source code

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Here is the source code for org.jclouds.openstack.marconi.v1.domain.MessageStream.java

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/*
 * 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.marconi.v1.domain;

import com.google.common.base.Function;
import com.google.common.base.Optional;
import com.google.common.base.Predicate;
import com.google.common.collect.Iterables;
import com.google.common.collect.Multimap;
import org.jclouds.openstack.marconi.v1.options.StreamMessagesOptions;
import org.jclouds.openstack.v2_0.domain.Link;
import org.jclouds.openstack.v2_0.domain.PaginatedCollection;

import static org.jclouds.http.utils.Queries.queryParser;

public class MessageStream extends PaginatedCollection<Message> {
    protected MessageStream(Iterable<Message> resources, Iterable<Link> links) {
        super(resources, links);
    }

    /**
     * Only call this method if {@code nextMarker().isPresent()} returns true.
     *
     * @return The options necessary to get the next page of messages.
     */
    public StreamMessagesOptions nextStreamOptions() {
        return StreamMessagesOptions.class.cast(nextMarker().get());
    }

    @Override
    public Optional<Object> nextMarker() {
        Optional<Link> nextMarkerLink = Iterables.tryFind(getLinks(), IS_NEXT_LINK);
        return nextMarkerLink.transform(TO_LIST_OPTIONS);
    }

    private static final Predicate<Link> IS_NEXT_LINK = new Predicate<Link>() {
        @Override
        public boolean apply(Link link) {
            return Link.Relation.NEXT == link.getRelation();
        }
    };

    private static final Function<Link, Object> TO_LIST_OPTIONS = new Function<Link, Object>() {
        @Override
        public Object apply(Link link) {
            Multimap<String, String> queryParams = queryParser().apply(link.getHref().getRawQuery());
            StreamMessagesOptions paginationOptions = StreamMessagesOptions.Builder.queryParameters(queryParams);

            return paginationOptions;
        }
    };
}