Large files can be cut for multipart upload. User can use multipart upload mode in the following (but not limited to) application scenarios:
Breakpoint upload must be supported.
Upload the file whose capacity is over 5 GB.
The network condition is poor, and the link with the OSS server is often cut off.
Before uploading files, the size of files to be uploaded cannot be determined.
Multipart upload is divided into the following 3 steps::
Initiate a multipart upload task (InitiateMultipartUpload).
Perform multipart upload in serial or parallel manner (UploadPart).
Complete multipart upload (CompleteMultipartUpload) or undo multipart upload (AbortMultipartUpload).
// Initialized Multipart Upload
String bucket_name = "<your bucketname>";
String file_path = "<your loacl file>";
String key = Paths.get(file_path).getFileName().toString();
File file = new File(file_path);
long contentLength = file.length();
long partSize = 5 * 1024 * 1024; // configure the capacity of each multipart as 5 MB.
try {
// Create the Etag list of the object and retrieve the Etag of each multipart.
List<PartETag> partETags = new ArrayList<PartETag>();
// Initialized Multipart Upload
InitiateMultipartUploadRequest initRequest = new InitiateMultipartUploadRequest(bucket_name, key);
InitiateMultipartUploadResult initResponse = s3.initiateMultipartUpload(initRequest);
// Upload Multipart
long filePosition = 0;
for (int i = 1; filePosition < contentLength; i++) {
partSize = Math.min(partSize, (contentLength - filePosition));
UploadPartRequest uploadRequest = new UploadPartRequest()
.withBucketName(bucket_name)
.withKey(key)
.withUploadId(initResponse.getUploadId())
.withPartNumber(i)
.withFileOffset(filePosition)
.withFile(file)
.withPartSize(partSize);
// Upload multipart and add the retrieved Etag to the list.
UploadPartResult uploadResult = s3.uploadPart(uploadRequest);
partETags.add(uploadResult.getPartETag());
filePosition += partSize;
}
// Complete Multipart Upload
CompleteMultipartUploadRequest compRequest = new CompleteMultipartUploadRequest(bucket_name, key,
initResponse.getUploadId(), partETags);
s3.completeMultipartUpload(compRequest);
}
catch(AmazonServiceException e) {
e.printStackTrace();
}
catch(SdkClientException e) {
e.printStackTrace();
}
String bucket_name = "<your bucketname>";
try {
ListMultipartUploadsRequest allMultipartUploadsRequest = new ListMultipartUploadsRequest(bucket_name);
MultipartUploadListing multipartUploadListing = s3.listMultipartUploads(allMultipartUploadsRequest);
List<MultipartUpload> uploads = multipartUploadListing.getMultipartUploads();
System.out.println(uploads.size() + " multipart upload(s) in progress.");
for (MultipartUpload u : uploads) {
System.out.println("Upload in progress: Key = \"" + u.getKey() + "\", id = " + u.getUploadId());
}
}
catch(AmazonServiceException e) {
e.printStackTrace();
}
catch(SdkClientException e) {
e.printStackTrace();
}
String bucket_name = "<your bucketname>";
try {
// List all unfinished multipart upload.
ListMultipartUploadsRequest allMultipartUploadsRequest = new ListMultipartUploadsRequest(bucket_name);
MultipartUploadListing multipartUploadListing = s3.listMultipartUploads(allMultipartUploadsRequest);
List<MultipartUpload> uploads = multipartUploadListing.getMultipartUploads();
System.out.println("Before deletions, " + uploads.size() + " multipart uploads in progress.");
// Terminate Multipart Upload
for (MultipartUpload u : uploads) {
System.out.println("Upload in progress: Key = \"" + u.getKey() + "\", id = " + u.getUploadId());
s3.abortMultipartUpload(new AbortMultipartUploadRequest(bucket_name, u.getKey(), u.getUploadId()));
System.out.println("Upload deleted: Key = \"" + u.getKey() + "\", id = " + u.getUploadId());
}
// Verify all unfinished multipart upload and check whether it is terminated.
multipartUploadListing = s3.listMultipartUploads(allMultipartUploadsRequest);
uploads = multipartUploadListing.getMultipartUploads();
System.out.println("After aborting uploads, " + uploads.size() + " multipart uploads in progress.");
}
catch(AmazonServiceException e) {
e.printStackTrace();
}
catch(SdkClientException e) {
e.printStackTrace();
}