拷贝文件

以下代码用于拷贝小文件：

// Endpoint以杭州为例，其它Region请按实际情况填写。
String endpoint = "http://oss-cn-hangzhou.aliyuncs.com";
// 阿里云主账号AccessKey拥有所有API的访问权限，风险很高。强烈建议您创建并使用RAM账号进行API访问或日常运维，请登录 https://ram.console.aliyun.com 创建RAM账号。
String accessKeyId = "<yourAccessKeyId>";
String accessKeySecret = "<yourAccessKeySecret>";

// 创建OSSClient实例。
OSS ossClient = new OSSClientBuilder().build(endpoint, accessKeyId, accessKeySecret);

String sourceBucketName = "<yourSourceBucketName>";
String sourceObjectName = "<yourSourceObjectName>";
String destinationBucketName = "<yourDestinationBucketName>";
String destinationObjectName = "<yourDestinationObjectName>";
String versionid = "<yourSourceObjectVersionid>";

CopyObjectRequest copyObjectRequest = new CopyObjectRequest(sourceBucketName, sourceObjectName, destinationBucketName, destinationObjectName);
copyObjectRequest.setSourceVersionId(versionid);
CopyObjectResult copyObjectResult = ossClient.copyObject(copyObjectRequest);
System.out.println("ETag: " + copyObjectResult.getETag() + " LastModified: " + copyObjectResult.getLastModified());
System.out.println("dest object versionid: " + copyObjectResult.getVersionId());

// 关闭OSSClient。
ossClient.shutdown();

UploadPartCopy默认从一个已存在的Object的当前版本中拷贝数据来上传一个Part。允许通过在请求header : x-oss-copy-source中附带versionId的子条件，实现从Object的指定版本进行拷贝，如x-oss-copy-source : /SourceBucketName/SourceObjectName?versionId=111111。

以下代码用于分片拷贝：

// Endpoint以杭州为例，其它Region请按实际情况填写。
String endpoint = "http://oss-cn-hangzhou.aliyuncs.com";
// 阿里云主账号AccessKey拥有所有API的访问权限，风险很高。强烈建议您创建并使用RAM账号进行API访问或日常运维，请登录 https://ram.console.aliyun.com 创建RAM账号。
String accessKeyId = "<yourAccessKeyId>";
String accessKeySecret = "<yourAccessKeySecret>";

String sourceBucketName = "<yourSourceBucketName>";
String sourceObjectName = "<yourSourceObjectName>";
String destinationBucketName = "<yourDestinationBucketName>";
String destinationObjectName = "<yourDestinationObjectName>";
String sourceObjectVersionid = "<yourSourceObjectVersionid>";

ObjectMetadata objectMetadata = ossClient.getObjectMetadata(sourceBucketName, sourceObjectName, sourceObjectVersionid);
// 获取被拷贝文件的大小。
long contentLength = objectMetadata.getContentLength();
// 设置分片大小为10MB。
long partSize = 1024 * 1024 * 10;
// 计算分片总数。
int partCount = (int) (contentLength / partSize);
if (contentLength % partSize != 0) {
    partCount++;
}

System.out.println("total part count:" + partCount);
// 初始化拷贝任务。可以通过InitiateMultipartUploadRequest指定目标文件元信息。
InitiateMultipartUploadRequest initiateMultipartUploadRequest = new InitiateMultipartUploadRequest(destinationBucketName, destinationObjectName);
InitiateMultipartUploadResult initiateMultipartUploadResult = ossClient.initiateMultipartUpload(initiateMultipartUploadRequest);
String uploadId = initiateMultipartUploadResult.getUploadId();

// 分片拷贝。
List<PartETag> partETags = new ArrayList<PartETag>();
for (int i = 0; i < partCount; i++) {
     // 计算每个分片的大小。
    long skipBytes = partSize * i;
    long size = partSize < contentLength - skipBytes ? partSize : contentLength - skipBytes;

    // 创建UploadPartCopyRequest。可以通过UploadPartCopyRequest指定限定条件。
    UploadPartCopyRequest uploadPartCopyRequest =
        new UploadPartCopyRequest(sourceBucketName, sourceObjectName, destinationBucketName, destinationObjectName);
    uploadPartCopyRequest.setUploadId(uploadId);
    uploadPartCopyRequest.setPartSize(size);
    uploadPartCopyRequest.setBeginIndex(skipBytes);
    uploadPartCopyRequest.setPartNumber(i + 1);
    // 指定源文件版本id。
    uploadPartCopyRequest.setSourceVersionId(sourceObjectVersionid);
    UploadPartCopyResult uploadPartCopyResult = ossClient.uploadPartCopy(uploadPartCopyRequest);

    // 将返回的分片ETag保存到partETags中。
    partETags.add(uploadPartCopyResult.getPartETag());
}

// 提交分片拷贝任务。
CompleteMultipartUploadRequest completeMultipartUploadRequest = new CompleteMultipartUploadRequest(
                    destinationBucketName, destinationObjectName, uploadId, partETags);
CompleteMultipartUploadResult completeMultipartUploadResult = ossClient.completeMultipartUpload(completeMultipartUploadRequest);
// 查看目标文件的版本id。
System.out.println("object versionid: " + completeMultipartUploadResult.getVersionId());

// 关闭OSSClient。
ossClient.shutdown();