/*
* Copyright 2013-2016 Amazon Technologies, 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://aws.amazon.com/apache2.0
*
* 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 com.amazonaws.regions;
import static com.amazonaws.SDKGlobalConfiguration.REGIONS_FILE_OVERRIDE_SYSTEM_PROPERTY;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.LinkedList;
import java.util.List;
/**
* Utilities for working with regions.
*/
public class RegionUtils {
private static List<Region> regions;
// Use the same logger as the http client
private static final Log log = LogFactory.getLog("com.amazonaws.request");
/**
* Returns a list of the available AWS regions.
*/
public synchronized static List<Region> getRegions() {
if (regions == null) {
init();
}
return regions;
}
/**
* Returns a list of the regions that support the service given.
*
* @see ServiceAbbreviations
*/
public synchronized static List<Region> getRegionsForService(String serviceAbbreviation) {
List<Region> regions = new LinkedList<Region>();
for (Region r : getRegions()) {
if (r.isServiceSupported(serviceAbbreviation)) {
regions.add(r);
}
}
return regions;
}
/**
* Returns the region with the id given, if it exists. Otherwise, returns
* null.
*/
public static Region getRegion(String regionName) {
for (Region r : getRegions()) {
if (r.getName().equals(regionName)) {
return r;
}
}
return null;
}
/**
* Searches through all known regions to find one with any service at the
* specified endpoint. If no region is found with a service at that
* endpoint, an exception is thrown.
*
* @param endpoint The endpoint for any service residing in the desired
* region.
* @return The region containing any service running at the specified
* endpoint, otherwise an exception is thrown if no region is found
* with a service at the specified endpoint.
* @throws MalformedURLException If the given URL is malformed, or if the
* one of the service URLs on record is malformed.
*/
public static Region getRegionByEndpoint(String endpoint) {
URI targetEndpointUri = getUriByEndpoint(endpoint);
String targetHost = targetEndpointUri.getHost();
for (Region region : getRegions()) {
for (String serviceEndpoint : region.getServiceEndpoints().values()) {
URI serviceEndpointUrl = getUriByEndpoint(serviceEndpoint);
if (serviceEndpointUrl.getHost().equals(targetHost))
return region;
}
}
throw new IllegalArgumentException("No region found with any service for endpoint "
+ endpoint);
}
/**
* There is no need to call this method, it is public only for
* Compatibility. Every regions method makes sure this method has already
* been called. This method will load the regions (specified by the
* developer if the system property
* SDKGlobalConfiguraiton.REGIONS_FILE_OVERRIDE_SYSTEM_PROPERTY is set, or
* the defaults shipped with the SDK) into memory.
*/
public static synchronized void init() {
if (System.getProperty(REGIONS_FILE_OVERRIDE_SYSTEM_PROPERTY) != null) {
try {
loadRegionsFromOverrideFile();
} catch (FileNotFoundException e) {
throw new RuntimeException("Couldn't find regions override file specified", e);
}
}
// Fall back onto the version we ship with the SDK
if (regions == null) {
initSDKRegions();
}
// Throw out RuntimeException explicitly
if (regions == null) {
throw new RuntimeException("Failed to initialize the regions.");
}
}
private static void loadRegionsFromOverrideFile() throws FileNotFoundException {
String overrideFilePath = System.getProperty(REGIONS_FILE_OVERRIDE_SYSTEM_PROPERTY);
if (log.isDebugEnabled()) {
log.debug("Using local override of the regions file ("
+ overrideFilePath
+ ") to initiate regions data...");
}
File regionsFile = new File(overrideFilePath);
FileInputStream override = new FileInputStream(regionsFile);
initRegions(override);
}
/**
* Tries to initialize the regions list from the stream given.
*
* @param regionsFile The input stream pointing to the retrieved region
* file.
*/
private static void initRegions(InputStream regionsFile) {
try {
RegionMetadataParser parser = new RegionMetadataParser();
regions = parser.parseRegionMetadata(regionsFile);
} catch (Exception e) {
log.warn("Failed to parse regional endpoints", e);
}
}
/**
* Failsafe method to initialize the regions list from the list bundled with
* the SDK, in case it cannot be fetched from the remote source.
*/
private static void initSDKRegions() {
if (log.isDebugEnabled()) {
log.debug("Initializing the regions with default regions");
}
regions = RegionDefaults.getRegions();
}
/**
* Get the URI object for the given endpoint. URI class cannot correctly
* parse the endpoint if it doesn't include protocol. This method will add
* the protocol if this happens.
*/
private static URI getUriByEndpoint(String endpoint) {
URI targetEndpointUri = null;
try {
targetEndpointUri = new URI(endpoint);
if (targetEndpointUri.getHost() == null) {
targetEndpointUri = new URI("http://" + endpoint);
}
} catch (URISyntaxException e) {
throw new RuntimeException("Unable to parse service endpoint: " + e.getMessage());
}
return targetEndpointUri;
}
}