com.twitter.hbc.core.HttpHosts.java Source code

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Here is the source code for com.twitter.hbc.core.HttpHosts.java

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/**
 * Copyright 2013 Twitter, Inc.
 * Licensed 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 com.twitter.hbc.core;

import com.google.common.base.Preconditions;
import com.google.common.collect.Iterables;
import com.google.common.collect.Iterators;
import com.google.common.collect.Lists;

import java.util.Collections;
import java.util.Iterator;
import java.util.List;

public class HttpHosts implements Hosts {

    private final Iterator<String> hosts;

    public HttpHosts(String address) {
        this(Collections.singletonList(address));
    }

    /**
     * All httpHosts must start with the http scheme("http:// or https://")
     */
    public HttpHosts(Iterable<String> addresses) {
        Preconditions.checkNotNull(addresses);
        Preconditions.checkArgument(!Iterables.isEmpty(addresses));
        for (String address : addresses) {
            if (!address.toLowerCase().startsWith(HttpConstants.HTTP_SCHEME + "://")
                    && !address.toLowerCase().startsWith(HttpConstants.HTTPS_SCHEME + "://")) {
                throw new IllegalArgumentException("Address doesn't have an http scheme: " + address);
            }
        }
        List<String> copy = Lists.newArrayList(addresses);
        Collections.shuffle(copy);
        this.hosts = Iterators.cycle(copy);
    }

    @Override
    public String nextHost() {
        return hosts.next();
    }

    public static final HttpHosts STREAM_HOST = new HttpHosts("https://stream.twitter.com");
    public static final HttpHosts USERSTREAM_HOST = new HttpHosts("https://userstream.twitter.com");
    public static final HttpHosts SITESTREAM_HOST = new HttpHosts("https://sitestream.twitter.com");
}