Java tutorial
/* * Licensed to CRATE Technology GmbH ("Crate") under one or more contributor * license agreements. See the NOTICE file distributed with this work for * additional information regarding copyright ownership. Crate 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. * * However, if you have executed another commercial license agreement * with Crate these terms will supersede the license and you may use the * software solely pursuant to the terms of the relevant commercial agreement. */ package io.crate.external; import com.amazonaws.AmazonClientException; import com.amazonaws.ClientConfiguration; import com.amazonaws.Protocol; import com.amazonaws.auth.*; import com.amazonaws.retry.PredefinedRetryPolicies; import com.amazonaws.services.s3.AmazonS3; import com.amazonaws.services.s3.AmazonS3Client; import com.carrotsearch.hppc.IntObjectMap; import com.carrotsearch.hppc.IntObjectOpenHashMap; import javax.annotation.Nullable; import javax.annotation.concurrent.NotThreadSafe; import java.io.IOException; import java.net.URI; @NotThreadSafe public class S3ClientHelper { private final static AWSCredentialsProvider DEFAULT_CREDENTIALS_PROVIDER_CHAIN = new AWSCredentialsProviderChain( new EnvironmentVariableCredentialsProvider(), new SystemPropertiesCredentialsProvider(), new InstanceProfileCredentialsProvider()) { private AWSCredentials ANONYMOUS_CREDENTIALS = new AnonymousAWSCredentials(); public AWSCredentials getCredentials() { try { return super.getCredentials(); } catch (AmazonClientException ace) { // allow for anonymous access return ANONYMOUS_CREDENTIALS; } } }; private final static ClientConfiguration CLIENT_CONFIGURATION = new ClientConfiguration() .withProtocol(Protocol.HTTPS); static { CLIENT_CONFIGURATION.setRetryPolicy(PredefinedRetryPolicies.getDefaultRetryPolicyWithCustomMaxRetries(5)); CLIENT_CONFIGURATION.setUseTcpKeepAlive(true); } private final static String INVALID_URI_MSG = "Invalid URI. Please make sure that given URI is encoded properly."; private final IntObjectMap<AmazonS3> clientMap = new IntObjectOpenHashMap<>(1); protected AmazonS3 initClient(@Nullable String accessKey, @Nullable String secretKey) throws IOException { if (accessKey == null || secretKey == null) { return new AmazonS3Client(DEFAULT_CREDENTIALS_PROVIDER_CHAIN, CLIENT_CONFIGURATION); } return new AmazonS3Client(new BasicAWSCredentials(accessKey, secretKey), CLIENT_CONFIGURATION); } public AmazonS3 client(URI uri) throws IOException { String accessKey = null; String secretKey = null; if (uri.getHost() == null) { throw new IllegalArgumentException(INVALID_URI_MSG); } if (uri.getUserInfo() != null) { String[] userInfoParts = uri.getUserInfo().split(":"); try { accessKey = userInfoParts[0]; secretKey = userInfoParts[1]; } catch (ArrayIndexOutOfBoundsException e) { // ignore } // if the URI contains '@' and ':', a UserInfo is in fact given, but could not // be parsed properly because the URI is not valid (e.g. not properly encoded). } else if (uri.toString().contains("@") && uri.toString().contains(":")) { throw new IllegalArgumentException(INVALID_URI_MSG); } return client(accessKey, secretKey); } private AmazonS3 client(@Nullable String accessKey, @Nullable String secretKey) throws IOException { int hash = hash(accessKey, secretKey); AmazonS3 client = clientMap.get(hash); if (client == null) { client = initClient(accessKey, secretKey); clientMap.put(hash, client); } return client; } private static int hash(@Nullable String accessKey, @Nullable String secretKey) { return 31 * (accessKey == null ? 1 : accessKey.hashCode()) + (secretKey == null ? 1 : secretKey.hashCode()); } }