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.operation.collect.files; import com.amazonaws.services.s3.AmazonS3; import com.amazonaws.services.s3.model.ObjectListing; import com.amazonaws.services.s3.model.S3Object; import com.amazonaws.services.s3.model.S3ObjectSummary; import com.google.common.base.Predicate; import io.crate.external.S3ClientHelper; import org.elasticsearch.common.logging.ESLogger; import org.elasticsearch.common.logging.Loggers; import java.io.IOException; import java.io.InputStream; import java.net.URI; import java.util.ArrayList; import java.util.List; public class S3FileInput implements FileInput { private AmazonS3 client; // to prevent early GC during getObjectContent() in getStream() private static final ESLogger logger = Loggers.getLogger(S3FileInput.class); final S3ClientHelper clientBuilder; public S3FileInput() { clientBuilder = new S3ClientHelper(); } public S3FileInput(S3ClientHelper clientBuilder) { this.clientBuilder = clientBuilder; } @Override public List<URI> listUris(URI uri, Predicate<URI> uriPredicate) throws IOException { String bucketName = uri.getHost(); if (client == null) { client = clientBuilder.client(uri); } String prefix = uri.getPath().length() > 1 ? uri.getPath().substring(1) : ""; List<URI> uris = new ArrayList<>(); ObjectListing list = client.listObjects(bucketName, prefix); addKeyUris(uris, list, uri, uriPredicate); while (list.isTruncated()) { list = client.listNextBatchOfObjects(list); addKeyUris(uris, list, uri, uriPredicate); } return uris; } private void addKeyUris(List<URI> uris, ObjectListing list, URI uri, Predicate<URI> uriPredicate) { List<S3ObjectSummary> summaries = list.getObjectSummaries(); for (S3ObjectSummary summary : summaries) { String key = summary.getKey(); if (!key.endsWith("/")) { URI keyUri = uri.resolve("/" + key); if (uriPredicate.apply(keyUri)) { uris.add(keyUri); if (logger.isDebugEnabled()) { logger.debug("{}", keyUri); } } } } } @Override public InputStream getStream(URI uri) throws IOException { if (client == null) { client = clientBuilder.client(uri); } S3Object object = client.getObject(uri.getHost(), uri.getPath().substring(1)); if (object != null) { return object.getObjectContent(); } return null; } @Override public boolean sharedStorageDefault() { return true; } }