Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF 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. */ package org.apache.flink.fs.s3hadoop; import org.apache.flink.fs.s3.common.writer.S3AccessHelper; import org.apache.flink.util.MathUtils; import com.amazonaws.SdkBaseException; import com.amazonaws.services.s3.model.CompleteMultipartUploadResult; import com.amazonaws.services.s3.model.ObjectMetadata; import com.amazonaws.services.s3.model.PartETag; import com.amazonaws.services.s3.model.PutObjectRequest; import com.amazonaws.services.s3.model.PutObjectResult; import com.amazonaws.services.s3.model.UploadPartRequest; import com.amazonaws.services.s3.model.UploadPartResult; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.Path; import org.apache.hadoop.fs.s3a.S3AFileSystem; import org.apache.hadoop.fs.s3a.S3AUtils; import org.apache.hadoop.fs.s3a.WriteOperationHelper; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.OutputStream; import java.util.List; import java.util.concurrent.atomic.AtomicInteger; import static org.apache.flink.util.Preconditions.checkNotNull; /** * An implementation of the {@link S3AccessHelper} for the Hadoop S3A filesystem. */ public class HadoopS3AccessHelper implements S3AccessHelper { private final S3AFileSystem s3a; private final InternalWriteOperationHelper s3accessHelper; public HadoopS3AccessHelper(S3AFileSystem s3a, Configuration conf) { this.s3accessHelper = new InternalWriteOperationHelper(checkNotNull(s3a), checkNotNull(conf)); this.s3a = s3a; } @Override public String startMultiPartUpload(String key) throws IOException { return s3accessHelper.initiateMultiPartUpload(key); } @Override public UploadPartResult uploadPart(String key, String uploadId, int partNumber, File inputFile, long length) throws IOException { final UploadPartRequest uploadRequest = s3accessHelper.newUploadPartRequest(key, uploadId, partNumber, MathUtils.checkedDownCast(length), null, inputFile, 0L); return s3accessHelper.uploadPart(uploadRequest); } @Override public PutObjectResult putObject(String key, File inputFile) throws IOException { final PutObjectRequest putRequest = s3accessHelper.createPutObjectRequest(key, inputFile); return s3accessHelper.putObject(putRequest); } @Override public CompleteMultipartUploadResult commitMultiPartUpload(String destKey, String uploadId, List<PartETag> partETags, long length, AtomicInteger errorCount) throws IOException { return s3accessHelper.completeMPUwithRetries(destKey, uploadId, partETags, length, errorCount); } @Override public boolean deleteObject(String key) throws IOException { return s3a.delete(new org.apache.hadoop.fs.Path('/' + key), false); } @Override public long getObject(String key, File targetLocation) throws IOException { long numBytes = 0L; try (final OutputStream outStream = new FileOutputStream(targetLocation); final org.apache.hadoop.fs.FSDataInputStream inStream = s3a .open(new org.apache.hadoop.fs.Path('/' + key))) { final byte[] buffer = new byte[32 * 1024]; int numRead; while ((numRead = inStream.read(buffer)) != -1) { outStream.write(buffer, 0, numRead); numBytes += numRead; } } // some sanity checks if (numBytes != targetLocation.length()) { throw new IOException(String.format( "Error recovering writer: " + "Downloading the last data chunk file gives incorrect length. " + "File=%d bytes, Stream=%d bytes", targetLocation.length(), numBytes)); } return numBytes; } @Override public ObjectMetadata getObjectMetadata(String key) throws IOException { try { return s3a.getObjectMetadata(new Path('/' + key)); } catch (SdkBaseException e) { throw S3AUtils.translateException("getObjectMetadata", key, e); } } /** * Internal {@link WriteOperationHelper} that is wrapped so that it only exposes * the functionality we need for the {@link S3AccessHelper}. */ private static final class InternalWriteOperationHelper extends WriteOperationHelper { InternalWriteOperationHelper(S3AFileSystem owner, Configuration conf) { super(owner, conf); } } }