org.jclouds.aws.suppliers.DefaultLocationSupplier.java Source code

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Here is the source code for org.jclouds.aws.suppliers.DefaultLocationSupplier.java

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/**
 *
 * Copyright (C) 2010 Cloud Conscious, LLC. <info@cloudconscious.com>
 *
 * ====================================================================
 * 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 org.jclouds.aws.suppliers;

import java.util.NoSuchElementException;
import java.util.Set;

import javax.inject.Inject;
import javax.inject.Singleton;

import org.jclouds.aws.Region;
import org.jclouds.collect.Memoized;
import org.jclouds.domain.Location;
import org.jclouds.domain.LocationScope;

import com.google.common.base.Predicate;
import com.google.common.base.Supplier;
import com.google.common.collect.Iterables;

/**
 * @author Adrian Cole
 */
@Singleton
public class DefaultLocationSupplier implements Supplier<Location> {
    private final String region;
    private final Supplier<Set<? extends Location>> set;

    @Inject
    DefaultLocationSupplier(@Region final String region, @Memoized Supplier<Set<? extends Location>> set) {
        this.region = region;
        this.set = set;
    }

    @Override
    @Singleton
    public Location get() {
        try {
            Location toReturn = Iterables.find(set.get(), new Predicate<Location>() {

                @Override
                public boolean apply(Location input) {
                    switch (input.getScope()) {
                    case ZONE:
                        return input.getParent().getId().equals(region);
                    case REGION:
                        return input.getId().equals(region);
                    default:
                        return false;
                    }
                }

            });
            return toReturn.getScope() == LocationScope.REGION ? toReturn : toReturn.getParent();
        } catch (NoSuchElementException e) {
            throw new IllegalStateException(String.format("region: %s not found in %s", region, set));
        }
    }
}