Amazon Glacier
开发人员指南 (API 版本 2012-06-01)
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使用AWS SDK for Java在 Amazon Glacier 中下载档案

适用于 Java 的 AWS 开发工具包所提供的高级 API 和低级 API 都提供了一个方法来下载档案。

使用AWS SDK for Java高级 API 下载档案

该高级 API 的 ArchiveTransferManager 类提供了您可以用来下载档案的 download 方法。

重要

ArchiveTransferManager 类创建了 Amazon Simple Notification Service (Amazon SNS) 主题以及订阅该主题的 Amazon Simple Queue Service (Amazon SQS) 队列。然后,它启动了档案检索任务,并对队列进行轮询以便找到可用档案。如果存档可用,则开始下载。有关检索时间的详细信息,请参阅 档案检索选项

示例:使用AWS SDK for Java的高级 API 下载档案

以下 Java 代码示例将从 美国西部(俄勒冈) 区域 (us-west-2) 中的文件库 (examplevault) 中下载档案。

有关运行此示例的分步说明,请参阅“使用 Eclipse 运行 Amazon Glacier 的 Java 示例”。您需要更新现有档案 ID 和已下载档案的本地文件保存路径旁显示的代码。

import java.io.File; import java.io.IOException; import com.amazonaws.auth.profile.ProfileCredentialsProvider; import com.amazonaws.services.glacier.AmazonGlacierClient; import com.amazonaws.services.glacier.transfer.ArchiveTransferManager; import com.amazonaws.services.sns.AmazonSNSClient; import com.amazonaws.services.sqs.AmazonSQSClient; public class ArchiveDownloadHighLevel { public static String vaultName = "examplevault"; public static String archiveId = "*** provide archive ID ***"; public static String downloadFilePath = "*** provide location to download archive ***"; public static AmazonGlacierClient glacierClient; public static AmazonSQSClient sqsClient; public static AmazonSNSClient snsClient; public static void main(String[] args) throws IOException { ProfileCredentialsProvider credentials = new ProfileCredentialsProvider(); glacierClient = new AmazonGlacierClient(credentials); sqsClient = new AmazonSQSClient(credentials); snsClient = new AmazonSNSClient(credentials); glacierClient.setEndpoint("glacier.us-west-2.amazonaws.com"); sqsClient.setEndpoint("sqs.us-west-2.amazonaws.com"); snsClient.setEndpoint("sns.us-west-2.amazonaws.com"); try { ArchiveTransferManager atm = new ArchiveTransferManager(glacierClient, sqsClient, snsClient); atm.download(vaultName, archiveId, new File(downloadFilePath)); System.out.println("Downloaded file to " + downloadFilePath); } catch (Exception e) { System.err.println(e); } } }

使用AWS SDK for Java低级 API 下载档案

以下是使用AWS SDK for Java低级 API 检索文件库清单的步骤。

  1. 创建 AmazonGlacierClient 类(客户端)的实例。

    您需要指定要从中下载档案的 AWS 区域。您使用此客户端执行的所有操作都会应用到该区域。

  2. 通过执行 initiateJob 方法启动 archive-retrieval 任务。

    您可以通过创建一个 InitiateJobRequest 类的实例提供任务信息,例如,您要下载的档案的档案 ID,以及您希望 Amazon Glacier 向其发布任务完成消息的可选 Amazon SNS 主题。作为响应,Amazon Glacier 返回任务 ID。该响应位于一个 InitiateJobResult 类的实例中。

    JobParameters jobParameters = new JobParameters() .withArchiveId("*** provide an archive id ***") .withDescription("archive retrieval") .withRetrievalByteRange("*** provide a retrieval range***") // optional .withType("archive-retrieval"); InitiateJobResult initiateJobResult = client.initiateJob(new InitiateJobRequest() .withJobParameters(jobParameters) .withVaultName(vaultName)); String jobId = initiateJobResult.getJobId();

    您可以选择指定字节范围,以请求 Amazon Glacier 只准备档案的一部分。例如,您可以通过添加以下语句更新前面的请求,以请求 Amazon Glacier 只准备档案的 1MB 到 2MB 部分。

    int ONE_MEG = 1048576; String retrievalByteRange = String.format("%s-%s", ONE_MEG, 2*ONE_MEG -1); JobParameters jobParameters = new JobParameters() .withType("archive-retrieval") .withArchiveId(archiveId) .withRetrievalByteRange(retrievalByteRange) .withSNSTopic(snsTopicARN); InitiateJobResult initiateJobResult = client.initiateJob(new InitiateJobRequest() .withJobParameters(jobParameters) .withVaultName(vaultName)); String jobId = initiateJobResult.getJobId();

  3. 等待任务完成。

    您必须等到任务输出已作好供您下载的准备。如果您在文件库中设置了标识 Amazon Simple Notification Service (Amazon SNS) 主题的通知配置,或者在启动任务时指定了 Amazon SNS 主题,则 Amazon Glacier 会在完成任务后向该主题发送消息。

    此外,您还可以通过调用 describeJob 方法轮询 Amazon Glacier 来确定任务完成状态。尽管如此,使用 Amazon SNS 主题进行通知才是推荐的方法。

  4. 通过执行 getJobOutput 方法下载任务输出(档案数据)。

    您可以通过创建一个 GetJobOutputRequest 类的实例来提供请求信息,例如,任务 ID 和文件库名称。Amazon Glacier 返回的输出位于 GetJobOutputResult 对象中。

    GetJobOutputRequest jobOutputRequest = new GetJobOutputRequest() .withJobId("*** provide a job ID ***") .withVaultName("*** provide a vault name ****"); GetJobOutputResult jobOutputResult = client.getJobOutput(jobOutputRequest); // jobOutputResult.getBody() // Provides the input stream.

    前面的代码段会下载整个任务输出。您可以选择性地只取回输出的一部分,或者通过在您的 GetJobOutputRequest 中指定字节范围以较小的区块下载整个输出。

    GetJobOutputRequest jobOutputRequest = new GetJobOutputRequest() .withJobId("*** provide a job ID ***") .withRange("bytes=0-1048575") // Download only the first 1 MB of the output. .withVaultName("*** provide a vault name ****");

    在响应您的 GetJobOutput 调用时,Amazon Glacier 返回您下载的数据部分的校验和(如果满足特定条件)。有关更多信息,请参阅 下载数据时接收校验和

    要确认下载中没有错误,您随后可以在客户端计算校验和,并将它与 Amazon Glacier 在响应中发送的校验和相比较。

    对于指定了可选范围的档案取回任务,您在获取任务描述时,它会包括您要取回的范围的校验和 (SHA256TreeHash)。您可以使用此值进一步确认您稍后下载的整个字节范围的准确性。例如,如果您启动任务以取回以树形哈希对齐的档案范围,然后以区块下载输出,使得您的每个 GetJobOutput 请求均返回一个校验和,则您可以在客户端计算您下载的每个部分的校验和,然后计算树形哈希。您可以将它与 Amazon Glacier 为响应您的描述任务请求而返回的校验和相比较,以确认您下载的整个字节范围与 Amazon Glacier 中存储的字节范围相同。

    要了解可工作的示例,请参阅示例 2:使用AWS SDK for Java低级 API 检索档案 – 按区块下载输出

示例 1:使用AWS SDK for Java低级 API 上传档案

以下 Java 代码示例会从指定的文件库下载档案。任务完成后,该示例会在单一 getJobOutput 调用中下载整个输出。有关以区块下载输出的示例,请参阅“示例 2:使用AWS SDK for Java低级 API 检索档案 – 按区块下载输出 ”。

该示例执行以下任务:

  • 创建一个 Amazon Simple Notification Service (Amazon SNS) 主题。

    完成任务后,Amazon Glacier 会向此主题发送通知。

  • 创建一个 Amazon Simple Queue Service (Amazon SQS) 队列。

    该示例会向该队列附加策略,以使 Amazon SNS 主题能够向该队列发布消息。

  • 启动任务以下载指定的档案。

    在任务请求中,指定了创建的 Amazon SNS 主题,以便 Amazon Glacier 可以在完成任务后向该主题发布通知。

  • 定期检查 Amazon SQS 队列是否有包含该任务 ID 的消息。

    如果有消息,则分析 JSON,并检查任务是否已成功完成。如果已成功完成,则下载档案。

  • 通过删除它创建的 Amazon SNS 主题和 Amazon SQS 队列清除相关数据。

import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.FileOutputStream; import java.io.FileWriter; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStream; import java.util.HashMap; import java.util.List; import java.util.Map; import org.codehaus.jackson.JsonFactory; import org.codehaus.jackson.JsonNode; import org.codehaus.jackson.JsonParseException; import org.codehaus.jackson.JsonParser; import org.codehaus.jackson.map.ObjectMapper; import com.amazonaws.AmazonClientException; import com.amazonaws.auth.policy.Policy; import com.amazonaws.auth.policy.Principal; import com.amazonaws.auth.policy.Resource; import com.amazonaws.auth.policy.Statement; import com.amazonaws.auth.policy.Statement.Effect; import com.amazonaws.auth.policy.actions.SQSActions; import com.amazonaws.auth.profile.ProfileCredentialsProvider; import com.amazonaws.services.glacier.AmazonGlacierClient; import com.amazonaws.services.glacier.model.GetJobOutputRequest; import com.amazonaws.services.glacier.model.GetJobOutputResult; import com.amazonaws.services.glacier.model.InitiateJobRequest; import com.amazonaws.services.glacier.model.InitiateJobResult; import com.amazonaws.services.glacier.model.JobParameters; import com.amazonaws.services.sns.AmazonSNSClient; import com.amazonaws.services.sns.model.CreateTopicRequest; import com.amazonaws.services.sns.model.CreateTopicResult; import com.amazonaws.services.sns.model.DeleteTopicRequest; import com.amazonaws.services.sns.model.SubscribeRequest; import com.amazonaws.services.sns.model.SubscribeResult; import com.amazonaws.services.sns.model.UnsubscribeRequest; import com.amazonaws.services.sqs.AmazonSQSClient; import com.amazonaws.services.sqs.model.CreateQueueRequest; import com.amazonaws.services.sqs.model.CreateQueueResult; import com.amazonaws.services.sqs.model.DeleteQueueRequest; import com.amazonaws.services.sqs.model.GetQueueAttributesRequest; import com.amazonaws.services.sqs.model.GetQueueAttributesResult; import com.amazonaws.services.sqs.model.Message; import com.amazonaws.services.sqs.model.ReceiveMessageRequest; import com.amazonaws.services.sqs.model.SetQueueAttributesRequest; public class AmazonGlacierDownloadArchiveWithSQSPolling { public static String archiveId = "*** provide archive ID ****"; public static String vaultName = "*** provide vault name ***"; public static String snsTopicName = "*** provide topic name ***"; public static String sqsQueueName = "*** provide queue name ***"; public static String sqsQueueARN; public static String sqsQueueURL; public static String snsTopicARN; public static String snsSubscriptionARN; public static String fileName = "*** provide file name ***"; public static String region = "*** region ***"; public static long sleepTime = 600; public static AmazonGlacierClient client; public static AmazonSQSClient sqsClient; public static AmazonSNSClient snsClient; public static void main(String[] args) throws IOException { ProfileCredentialsProvider credentials = new ProfileCredentialsProvider(); client = new AmazonGlacierClient(credentials); client.setEndpoint("https://glacier." + region + ".amazonaws.com"); sqsClient = new AmazonSQSClient(credentials); sqsClient.setEndpoint("https://sqs." + region + ".amazonaws.com"); snsClient = new AmazonSNSClient(credentials); snsClient.setEndpoint("https://sns." + region + ".amazonaws.com"); try { setupSQS(); setupSNS(); String jobId = initiateJobRequest(); System.out.println("Jobid = " + jobId); Boolean success = waitForJobToComplete(jobId, sqsQueueURL); if (!success) { throw new Exception("Job did not complete successfully."); } downloadJobOutput(jobId); cleanUp(); } catch (Exception e) { System.err.println("Archive retrieval failed."); System.err.println(e); } } private static void setupSQS() { CreateQueueRequest request = new CreateQueueRequest() .withQueueName(sqsQueueName); CreateQueueResult result = sqsClient.createQueue(request); sqsQueueURL = result.getQueueUrl(); GetQueueAttributesRequest qRequest = new GetQueueAttributesRequest() .withQueueUrl(sqsQueueURL) .withAttributeNames("QueueArn"); GetQueueAttributesResult qResult = sqsClient.getQueueAttributes(qRequest); sqsQueueARN = qResult.getAttributes().get("QueueArn"); Policy sqsPolicy = new Policy().withStatements( new Statement(Effect.Allow) .withPrincipals(Principal.AllUsers) .withActions(SQSActions.SendMessage) .withResources(new Resource(sqsQueueARN))); Map<String, String> queueAttributes = new HashMap<String, String>(); queueAttributes.put("Policy", sqsPolicy.toJson()); sqsClient.setQueueAttributes(new SetQueueAttributesRequest(sqsQueueURL, queueAttributes)); } private static void setupSNS() { CreateTopicRequest request = new CreateTopicRequest() .withName(snsTopicName); CreateTopicResult result = snsClient.createTopic(request); snsTopicARN = result.getTopicArn(); SubscribeRequest request2 = new SubscribeRequest() .withTopicArn(snsTopicARN) .withEndpoint(sqsQueueARN) .withProtocol("sqs"); SubscribeResult result2 = snsClient.subscribe(request2); snsSubscriptionARN = result2.getSubscriptionArn(); } private static String initiateJobRequest() { JobParameters jobParameters = new JobParameters() .withType("archive-retrieval") .withArchiveId(archiveId) .withSNSTopic(snsTopicARN); InitiateJobRequest request = new InitiateJobRequest() .withVaultName(vaultName) .withJobParameters(jobParameters); InitiateJobResult response = client.initiateJob(request); return response.getJobId(); } private static Boolean waitForJobToComplete(String jobId, String sqsQueueUrl) throws InterruptedException, JsonParseException, IOException { Boolean messageFound = false; Boolean jobSuccessful = false; ObjectMapper mapper = new ObjectMapper(); JsonFactory factory = mapper.getJsonFactory(); while (!messageFound) { List<Message> msgs = sqsClient.receiveMessage( new ReceiveMessageRequest(sqsQueueUrl).withMaxNumberOfMessages(10)).getMessages(); if (msgs.size() > 0) { for (Message m : msgs) { JsonParser jpMessage = factory.createJsonParser(m.getBody()); JsonNode jobMessageNode = mapper.readTree(jpMessage); String jobMessage = jobMessageNode.get("Message").getTextValue(); JsonParser jpDesc = factory.createJsonParser(jobMessage); JsonNode jobDescNode = mapper.readTree(jpDesc); String retrievedJobId = jobDescNode.get("JobId").getTextValue(); String statusCode = jobDescNode.get("StatusCode").getTextValue(); if (retrievedJobId.equals(jobId)) { messageFound = true; if (statusCode.equals("Succeeded")) { jobSuccessful = true; } } } } else { Thread.sleep(sleepTime * 1000); } } return (messageFound && jobSuccessful); } private static void downloadJobOutput(String jobId) throws IOException { GetJobOutputRequest getJobOutputRequest = new GetJobOutputRequest() .withVaultName(vaultName) .withJobId(jobId); GetJobOutputResult getJobOutputResult = client.getJobOutput(getJobOutputRequest); InputStream input = new BufferedInputStream(getJobOutputResult.getBody()); OutputStream output = null; try { output = new BufferedOutputStream(new FileOutputStream(fileName)); byte[] buffer = new byte[1024 * 1024]; int bytesRead = 0; do { bytesRead = input.read(buffer); if (bytesRead <= 0) break; output.write(buffer, 0, bytesRead); } while (bytesRead > 0); } catch (IOException e) { throw new AmazonClientException("Unable to save archive", e); } finally { try {input.close();} catch (Exception e) {} try {output.close();} catch (Exception e) {} } System.out.println("Retrieved archive to " + fileName); } private static void cleanUp() { snsClient.unsubscribe(new UnsubscribeRequest(snsSubscriptionARN)); snsClient.deleteTopic(new DeleteTopicRequest(snsTopicARN)); sqsClient.deleteQueue(new DeleteQueueRequest(sqsQueueURL)); } }

示例 2:使用AWS SDK for Java低级 API 检索档案 – 按区块下载输出

以下 Java 代码示例从 Amazon Glacier 检索档案。该代码示例会通过在 GetJobOutputRequest 数据元中指定字节范围来以区块下载任务输出。

import java.io.BufferedInputStream; import java.io.ByteArrayInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.util.HashMap; import java.util.List; import java.util.Map; import com.fasterxml.jackson.core.JsonFactory; import com.fasterxml.jackson.core.JsonParseException; import com.fasterxml.jackson.core.JsonParser; import com.fasterxml.jackson.databind.JsonNode; import com.fasterxml.jackson.databind.ObjectMapper; import com.amazonaws.auth.policy.Policy; import com.amazonaws.auth.policy.Principal; import com.amazonaws.auth.policy.Resource; import com.amazonaws.auth.policy.Statement; import com.amazonaws.auth.policy.Statement.Effect; import com.amazonaws.auth.policy.actions.SQSActions; import com.amazonaws.auth.profile.ProfileCredentialsProvider; import com.amazonaws.services.glacier.AmazonGlacierClient; import com.amazonaws.services.glacier.TreeHashGenerator; import com.amazonaws.services.glacier.model.GetJobOutputRequest; import com.amazonaws.services.glacier.model.GetJobOutputResult; import com.amazonaws.services.glacier.model.InitiateJobRequest; import com.amazonaws.services.glacier.model.InitiateJobResult; import com.amazonaws.services.glacier.model.JobParameters; import com.amazonaws.services.sns.AmazonSNSClient; import com.amazonaws.services.sns.model.CreateTopicRequest; import com.amazonaws.services.sns.model.CreateTopicResult; import com.amazonaws.services.sns.model.DeleteTopicRequest; import com.amazonaws.services.sns.model.SubscribeRequest; import com.amazonaws.services.sns.model.SubscribeResult; import com.amazonaws.services.sns.model.UnsubscribeRequest; import com.amazonaws.services.sqs.AmazonSQSClient; import com.amazonaws.services.sqs.model.CreateQueueRequest; import com.amazonaws.services.sqs.model.CreateQueueResult; import com.amazonaws.services.sqs.model.DeleteQueueRequest; import com.amazonaws.services.sqs.model.GetQueueAttributesRequest; import com.amazonaws.services.sqs.model.GetQueueAttributesResult; import com.amazonaws.services.sqs.model.Message; import com.amazonaws.services.sqs.model.ReceiveMessageRequest; import com.amazonaws.services.sqs.model.SetQueueAttributesRequest; public class ArchiveDownloadLowLevelWithRange { public static String vaultName = "*** provide vault name ***"; public static String archiveId = "*** provide archive id ***"; public static String snsTopicName = "glacier-temp-sns-topic"; public static String sqsQueueName = "glacier-temp-sqs-queue"; public static long downloadChunkSize = 4194304; // 4 MB public static String sqsQueueARN; public static String sqsQueueURL; public static String snsTopicARN; public static String snsSubscriptionARN; public static String fileName = "*** provide file name to save archive to ***"; public static String region = "*** region ***"; public static long sleepTime = 600; public static AmazonGlacierClient client; public static AmazonSQSClient sqsClient; public static AmazonSNSClient snsClient; public static void main(String[] args) throws IOException { ProfileCredentialsProvider credentials = new ProfileCredentialsProvider(); client = new AmazonGlacierClient(credentials); client.setEndpoint("https://glacier." + region + ".amazonaws.com"); sqsClient = new AmazonSQSClient(credentials); sqsClient.setEndpoint("https://sqs." + region + ".amazonaws.com"); snsClient = new AmazonSNSClient(credentials); snsClient.setEndpoint("https://sns." + region + ".amazonaws.com"); try { setupSQS(); setupSNS(); String jobId = initiateJobRequest(); System.out.println("Jobid = " + jobId); long archiveSizeInBytes = waitForJobToComplete(jobId, sqsQueueURL); if (archiveSizeInBytes==-1) { throw new Exception("Job did not complete successfully."); } downloadJobOutput(jobId, archiveSizeInBytes); cleanUp(); } catch (Exception e) { System.err.println("Archive retrieval failed."); System.err.println(e); } } private static void setupSQS() { CreateQueueRequest request = new CreateQueueRequest() .withQueueName(sqsQueueName); CreateQueueResult result = sqsClient.createQueue(request); sqsQueueURL = result.getQueueUrl(); GetQueueAttributesRequest qRequest = new GetQueueAttributesRequest() .withQueueUrl(sqsQueueURL) .withAttributeNames("QueueArn"); GetQueueAttributesResult qResult = sqsClient.getQueueAttributes(qRequest); sqsQueueARN = qResult.getAttributes().get("QueueArn"); Policy sqsPolicy = new Policy().withStatements( new Statement(Effect.Allow) .withPrincipals(Principal.AllUsers) .withActions(SQSActions.SendMessage) .withResources(new Resource(sqsQueueARN))); Map<String, String> queueAttributes = new HashMap<String, String>(); queueAttributes.put("Policy", sqsPolicy.toJson()); sqsClient.setQueueAttributes(new SetQueueAttributesRequest(sqsQueueURL, queueAttributes)); } private static void setupSNS() { CreateTopicRequest request = new CreateTopicRequest() .withName(snsTopicName); CreateTopicResult result = snsClient.createTopic(request); snsTopicARN = result.getTopicArn(); SubscribeRequest request2 = new SubscribeRequest() .withTopicArn(snsTopicARN) .withEndpoint(sqsQueueARN) .withProtocol("sqs"); SubscribeResult result2 = snsClient.subscribe(request2); snsSubscriptionARN = result2.getSubscriptionArn(); } private static String initiateJobRequest() { JobParameters jobParameters = new JobParameters() .withType("archive-retrieval") .withArchiveId(archiveId) .withSNSTopic(snsTopicARN); InitiateJobRequest request = new InitiateJobRequest() .withVaultName(vaultName) .withJobParameters(jobParameters); InitiateJobResult response = client.initiateJob(request); return response.getJobId(); } private static long waitForJobToComplete(String jobId, String sqsQueueUrl) throws InterruptedException, JsonParseException, IOException { Boolean messageFound = false; Boolean jobSuccessful = false; long archiveSizeInBytes = -1; ObjectMapper mapper = new ObjectMapper(); JsonFactory factory = mapper.getFactory(); while (!messageFound) { List<Message> msgs = sqsClient.receiveMessage( new ReceiveMessageRequest(sqsQueueUrl).withMaxNumberOfMessages(10)).getMessages(); if (msgs.size() > 0) { for (Message m : msgs) { JsonParser jpMessage = factory.createJsonParser(m.getBody()); JsonNode jobMessageNode = mapper.readTree(jpMessage); String jobMessage = jobMessageNode.get("Message").textValue(); JsonParser jpDesc = factory.createJsonParser(jobMessage); JsonNode jobDescNode = mapper.readTree(jpDesc); String retrievedJobId = jobDescNode.get("JobId").textValue(); String statusCode = jobDescNode.get("StatusCode").textValue(); archiveSizeInBytes = jobDescNode.get("ArchiveSizeInBytes").longValue(); if (retrievedJobId.equals(jobId)) { messageFound = true; if (statusCode.equals("Succeeded")) { jobSuccessful = true; } } } } else { Thread.sleep(sleepTime * 1000); } } return (messageFound && jobSuccessful) ? archiveSizeInBytes : -1; } private static void downloadJobOutput(String jobId, long archiveSizeInBytes) throws IOException { if (archiveSizeInBytes < 0) { System.err.println("Nothing to download."); return; } System.out.println("archiveSizeInBytes: " + archiveSizeInBytes); FileOutputStream fstream = new FileOutputStream(fileName); long startRange = 0; long endRange = (downloadChunkSize > archiveSizeInBytes) ? archiveSizeInBytes -1 : downloadChunkSize - 1; do { GetJobOutputRequest getJobOutputRequest = new GetJobOutputRequest() .withVaultName(vaultName) .withRange("bytes=" + startRange + "-" + endRange) .withJobId(jobId); GetJobOutputResult getJobOutputResult = client.getJobOutput(getJobOutputRequest); BufferedInputStream is = new BufferedInputStream(getJobOutputResult.getBody()); byte[] buffer = new byte[(int)(endRange - startRange + 1)]; System.out.println("Checksum received: " + getJobOutputResult.getChecksum()); System.out.println("Content range " + getJobOutputResult.getContentRange()); int totalRead = 0; while (totalRead < buffer.length) { int bytesRemaining = buffer.length - totalRead; int read = is.read(buffer, totalRead, bytesRemaining); if (read > 0) { totalRead = totalRead + read; } else { break; } } System.out.println("Calculated checksum: " + TreeHashGenerator.calculateTreeHash(new ByteArrayInputStream(buffer))); System.out.println("read = " + totalRead); fstream.write(buffer); startRange = startRange + (long)totalRead; endRange = ((endRange + downloadChunkSize) > archiveSizeInBytes) ? archiveSizeInBytes : (endRange + downloadChunkSize); is.close(); } while (endRange <= archiveSizeInBytes && startRange < archiveSizeInBytes); fstream.close(); System.out.println("Retrieved file to " + fileName); } private static void cleanUp() { snsClient.unsubscribe(new UnsubscribeRequest(snsSubscriptionARN)); snsClient.deleteTopic(new DeleteTopicRequest(snsTopicARN)); sqsClient.deleteQueue(new DeleteQueueRequest(sqsQueueURL)); } }