AWS 文档 AWS SDK示例 GitHub 存储库中还有更多SDK示例
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与 AWS SDK或GetObjectAttributes
一起使用 CLI
以下代码示例演示如何使用 GetObjectAttributes
。
操作示例是大型程序的代码摘录,必须在上下文中运行。在以下代码示例中,您可以查看此操作的上下文:
- C++
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- SDK对于 C++
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注意
还有更多相关信息 GitHub。查找完整示例,学习如何在 AWS 代码示例存储库
中进行设置和运行。 // ! Routine which retrieves the hash value of an object stored in an S3 bucket. /*! \param bucket: The name of the S3 bucket where the object is stored. \param key: The unique identifier (key) of the object within the S3 bucket. \param hashMethod: The hashing algorithm used to calculate the hash value of the object. \param[out] hashData: The retrieved hash. \param[out] partHashes: The part hashes if available. \param client: The S3 client instance used to retrieve the object. \return bool: Function succeeded. */ bool AwsDoc::S3::retrieveObjectHash(const Aws::String &bucket, const Aws::String &key, AwsDoc::S3::HASH_METHOD hashMethod, Aws::String &hashData, std::vector<Aws::String> *partHashes, const Aws::S3::S3Client &client) { Aws::S3::Model::GetObjectAttributesRequest request; request.SetBucket(bucket); request.SetKey(key); if (hashMethod == MD5) { Aws::Vector<Aws::S3::Model::ObjectAttributes> attributes; attributes.push_back(Aws::S3::Model::ObjectAttributes::ETag); request.SetObjectAttributes(attributes); Aws::S3::Model::GetObjectAttributesOutcome outcome = client.GetObjectAttributes( request); if (outcome.IsSuccess()) { const Aws::S3::Model::GetObjectAttributesResult &result = outcome.GetResult(); hashData = result.GetETag(); } else { std::cerr << "Error retrieving object etag attributes." << outcome.GetError().GetMessage() << std::endl; return false; } } else { // hashMethod != MD5 Aws::Vector<Aws::S3::Model::ObjectAttributes> attributes; attributes.push_back(Aws::S3::Model::ObjectAttributes::Checksum); request.SetObjectAttributes(attributes); Aws::S3::Model::GetObjectAttributesOutcome outcome = client.GetObjectAttributes( request); if (outcome.IsSuccess()) { const Aws::S3::Model::GetObjectAttributesResult &result = outcome.GetResult(); switch (hashMethod) { case AwsDoc::S3::DEFAULT: // NOLINT(*-branch-clone) break; // Default is not supported. #pragma clang diagnostic push #pragma ide diagnostic ignored "UnreachableCode" case AwsDoc::S3::MD5: break; // MD5 is not supported. #pragma clang diagnostic pop case AwsDoc::S3::SHA1: hashData = result.GetChecksum().GetChecksumSHA1(); break; case AwsDoc::S3::SHA256: hashData = result.GetChecksum().GetChecksumSHA256(); break; case AwsDoc::S3::CRC32: hashData = result.GetChecksum().GetChecksumCRC32(); break; case AwsDoc::S3::CRC32C: hashData = result.GetChecksum().GetChecksumCRC32C(); break; default: std::cerr << "Unknown hash method." << std::endl; return false; } } else { std::cerr << "Error retrieving object checksum attributes." << outcome.GetError().GetMessage() << std::endl; return false; } if (nullptr != partHashes) { attributes.clear(); attributes.push_back(Aws::S3::Model::ObjectAttributes::ObjectParts); request.SetObjectAttributes(attributes); outcome = client.GetObjectAttributes(request); if (outcome.IsSuccess()) { const Aws::S3::Model::GetObjectAttributesResult &result = outcome.GetResult(); const Aws::Vector<Aws::S3::Model::ObjectPart> parts = result.GetObjectParts().GetParts(); for (const Aws::S3::Model::ObjectPart &part: parts) { switch (hashMethod) { case AwsDoc::S3::DEFAULT: // Default is not supported. NOLINT(*-branch-clone) break; case AwsDoc::S3::MD5: // MD5 is not supported. break; case AwsDoc::S3::SHA1: partHashes->push_back(part.GetChecksumSHA1()); break; case AwsDoc::S3::SHA256: partHashes->push_back(part.GetChecksumSHA256()); break; case AwsDoc::S3::CRC32: partHashes->push_back(part.GetChecksumCRC32()); break; case AwsDoc::S3::CRC32C: partHashes->push_back(part.GetChecksumCRC32C()); break; default: std::cerr << "Unknown hash method." << std::endl; return false; } } } else { std::cerr << "Error retrieving object attributes for object parts." << outcome.GetError().GetMessage() << std::endl; return false; } } } return true; }
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有关API详细信息,请参阅 “AWS SDK for C++ API参考 GetObjectAttributes” 中的。
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- CLI
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- AWS CLI
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从对象检索元数据而不返回对象本身
以下
get-object-attributes
示例从对象doc1.rtf
检索元数据。aws s3api get-object-attributes \ --bucket
my-bucket
\ --keydoc1.rtf
\ --object-attributes"StorageClass"
"ETag"
"ObjectSize"
输出:
{ "LastModified": "2022-03-15T19:37:31+00:00", "VersionId": "IuCPjXTDzHNfldAuitVBIKJpF2p1fg4P", "ETag": "b662d79adeb7c8d787ea7eafb9ef6207", "StorageClass": "STANDARD", "ObjectSize": 405 }
有关更多信息,请参阅 GetObjectAttributesAmazon S3 API 参考中的。
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有关API详细信息,请参阅 “GetObjectAttributes AWS CLI
命令参考”。
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GetObjectAcl
GetObjectLegalHold