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分片拷贝(Java SDK)
最近更新时间:2024.02.04 18:31:02首次发布时间:2023.01.19 14:37:15

对象大于 5GiB 时,您可以使用 TOS Java SDK 的 uploadPartCopy 接口进行分片拷贝。

注意事项

  • 拷贝文件不支持跨区域的桶间拷贝。
  • 拷贝对象时,账号必须具备源对象的读取权限和目标桶的写入权限。
  • 拷贝对象时,可以保留所有元数据(默认值)或指定新的元数据。但 ACL 并未被保留,而是设置为私有。

示例代码

以下代码展示如何将 srcBucketName 桶中的 srcObjectKey 对象分片拷贝到 bucketName 桶中,并设置对象名为 objectKey

import com.volcengine.tos.TOSV2;
import com.volcengine.tos.TOSV2ClientBuilder;
import com.volcengine.tos.TosClientException;
import com.volcengine.tos.TosServerException;
import com.volcengine.tos.model.object.*;

import java.util.ArrayList;
import java.util.List;

public class UploadPartCopyExample {
    public static void main(String[] args) {
        String endpoint = "your endpoint";
        String region = "your region";
        String accessKey = System.getenv("TOS_ACCESS_KEY");
        String secretKey = System.getenv("TOS_SECRET_KEY");

        // 源桶名
        String srcBucketName = "src-bucket-example";
        // 源对象名,需保证对象存在,否则报404
        String srcObjectKey = "src_example_dir/example_object.txt";
        // 目的桶名
        String bucketName = "bucket-example";
        // 目的对象名,如果目的对象存在,默认会将其覆盖
        String objectKey = "dst_example_dir/example_object.txt";

        long partSize = 10 * 1024 * 1024;

        TOSV2 tos = new TOSV2ClientBuilder().build(region, endpoint, accessKey, secretKey);

        try{
            // 从源桶中获取待拷贝对象的大小
            HeadObjectV2Output headInfo = tos.headObject(new HeadObjectV2Input().setBucket(srcBucketName).setKey(srcObjectKey));
            long contentLength = headInfo.getContentLength();

            // 初始化分片拷贝任务
            CreateMultipartUploadInput create = new CreateMultipartUploadInput().setBucket(bucketName).setKey(objectKey);
            CreateMultipartUploadOutput created = tos.createMultipartUpload(create);
            String uploadID = created.getUploadID();

            // 进行分片拷贝
            List<UploadedPartV2> partList = new ArrayList<>();
            // 从位置 0 开始拷贝
            long rangeStart = 0, rangeEnd = 0;
            int partNumber = 1;
            while (rangeEnd < contentLength) {
                // 最长不能超过源对象长度
                rangeEnd = Math.min(rangeStart + partSize - 1, contentLength);
                UploadPartCopyV2Input input = new UploadPartCopyV2Input().setBucket(bucketName).setKey(objectKey)
                        .setUploadID(uploadID).setSourceBucket(srcBucketName).setSourceKey(srcObjectKey)
                        .setPartNumber(partNumber).setCopySourceRange(rangeStart, rangeEnd);
//                // 如果需要设置目的对象的 ACL/storageClass 等元数据,可参考以下代码
//                ObjectMetaRequestOptions options = new ObjectMetaRequestOptions();
//                // 指定 ACL 为 private
//                options.setAclType(ACLType.ACL_PRIVATE);
//                // 指定 storageClass 为标准存储
//                options.setStorageClass(StorageClassType.STORAGE_CLASS_STANDARD);
//                input.setOptions(options);
//                // 指定限定条件,源对象的 ETag 与指定的 ETag 匹配时才拷贝,
//                // 指定的 ETag 可通过 headObject 获取,此处的 "XXX" 仅为示例,请使用正确的 ETag
//                input.setCopySourceIfMatch("XXX");
                UploadPartCopyV2Output output = tos.uploadPartCopy(input);
                System.out.println("uploadPartCopy succeed, part's etag is " + output.getEtag());
                System.out.println("uploadPartCopy succeed, part's partNumber is " + output.getPartNumber());
                partList.add(new UploadedPartV2().setEtag(output.getEtag()).setPartNumber(output.getPartNumber()));
                rangeStart = rangeEnd + 1;
                partNumber++;
            }

            // 合并拷贝的分片
            CompleteMultipartUploadV2Input complete = new CompleteMultipartUploadV2Input().setBucket(bucketName)
                    .setKey(objectKey).setUploadID(uploadID).setUploadedParts(partList);
            CompleteMultipartUploadV2Output output = tos.completeMultipartUpload(complete);
            System.out.println("copyObject succeed, object's etag is " + output.getEtag());
            System.out.println("copyObject succeed, object's crc64 is " + output.getHashCrc64ecma());
        } catch (TosClientException e) {
            // 操作失败,捕获客户端异常,一般情况是请求参数错误,此时请求并未发送
            System.out.println("copyObject failed");
            System.out.println("Message: " + e.getMessage());
            if (e.getCause() != null) {
                e.getCause().printStackTrace();
            }
        } catch (TosServerException e) {
            // 操作失败,捕获服务端异常,可以获取到从服务端返回的详细错误信息
            System.out.println("copyObject failed");
            System.out.println("StatusCode: " + e.getStatusCode());
            System.out.println("Code: " + e.getCode());
            System.out.println("Message: " + e.getMessage());
            System.out.println("RequestID: " + e.getRequestID());
        } catch (Throwable t) {
            // 作为兜底捕获其他异常,一般不会执行到这里
            System.out.println("copyObject failed");
            System.out.println("unexpected exception, message: " + t.getMessage());
        }
    }
}

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