software.amazon.awssdk.regions.providers.AwsRegionProviderChain Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of bundle

A single bundled dependency that includes all service and dependent JARs with third-party libraries relocated to different namespaces.

There is a newer version: 2.5.20

Show newest version

/*
 * Copyright 2010-2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *  http://aws.amazon.com/apache2.0
 *
 * or in the "license" file accompanying this file. This file 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 software.amazon.awssdk.regions.providers;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import software.amazon.awssdk.annotations.SdkProtectedApi;
import software.amazon.awssdk.core.exception.SdkClientException;
import software.amazon.awssdk.regions.Region;

/**
 * Composite {@link AwsRegionProvider} that sequentially delegates to a chain of providers looking
 * for region information.
 *
 * Throws an {@link SdkClientException} if region could not be find in any of the providers.
 */
@SdkProtectedApi
public class AwsRegionProviderChain implements AwsRegionProvider {

    private static final Logger log = LoggerFactory.getLogger(AwsRegionProviderChain.class);

    private final List providers;

    public AwsRegionProviderChain(AwsRegionProvider... providers) {
        this.providers = new ArrayList<>(providers.length);
        Collections.addAll(this.providers, providers);
    }

    @Override
    public Region getRegion() throws SdkClientException {
        List exceptionMessages = null;

        for (AwsRegionProvider provider : providers) {
            try {
                final Region region = provider.getRegion();
                if (region != null) {
                    return region;
                }
            } catch (Exception e) {
                // Ignore any exceptions and move onto the next provider
                log.debug("Unable to load region from {}:{}", provider.toString(), e.getMessage());

                String message = provider.toString() + ": " + e.getMessage();
                if (exceptionMessages == null) {
                    exceptionMessages = new ArrayList<>();
                }
                exceptionMessages.add(message);
            }
        }

        throw SdkClientException.builder()
                                .message("Unable to load region from any of the providers in the chain " + this
                                     + ": " + exceptionMessages)
                                .build();
    }
}