use of com.dropbox.core.v2.files.UploadSessionCursor in project dropbox-sdk-java by dropbox.
the class Main method chunkedUploadFile.
/**
* Uploads a file in chunks using multiple requests. This approach is preferred for larger files
* since it allows for more efficient processing of the file contents on the server side and
* also allows partial uploads to be retried (e.g. network connection problem will not cause you
* to re-upload all the bytes).
*
* @param dbxClient Dropbox user authenticated client
* @param localFIle local file to upload
* @param dropboxPath Where to upload the file to within Dropbox
*/
private static void chunkedUploadFile(DbxClientV2 dbxClient, File localFile, String dropboxPath) {
long size = localFile.length();
// below to simplify the logic.
if (size < CHUNKED_UPLOAD_CHUNK_SIZE) {
System.err.println("File too small, use upload() instead.");
System.exit(1);
return;
}
long uploaded = 0L;
DbxException thrown = null;
// Chunked uploads have 3 phases, each of which can accept uploaded bytes:
//
// (1) Start: initiate the upload and get an upload session ID
// (2) Append: upload chunks of the file to append to our session
// (3) Finish: commit the upload and close the session
//
// We track how many bytes we uploaded to determine which phase we should be in.
String sessionId = null;
for (int i = 0; i < CHUNKED_UPLOAD_MAX_ATTEMPTS; ++i) {
if (i > 0) {
System.out.printf("Retrying chunked upload (%d / %d attempts)\n", i + 1, CHUNKED_UPLOAD_MAX_ATTEMPTS);
}
try (InputStream in = new FileInputStream(localFile)) {
// if this is a retry, make sure seek to the correct offset
in.skip(uploaded);
// (1) Start
if (sessionId == null) {
sessionId = dbxClient.files().uploadSessionStart().uploadAndFinish(in, CHUNKED_UPLOAD_CHUNK_SIZE).getSessionId();
uploaded += CHUNKED_UPLOAD_CHUNK_SIZE;
printProgress(uploaded, size);
}
UploadSessionCursor cursor = new UploadSessionCursor(sessionId, uploaded);
// (2) Append
while ((size - uploaded) > CHUNKED_UPLOAD_CHUNK_SIZE) {
dbxClient.files().uploadSessionAppendV2(cursor).uploadAndFinish(in, CHUNKED_UPLOAD_CHUNK_SIZE);
uploaded += CHUNKED_UPLOAD_CHUNK_SIZE;
printProgress(uploaded, size);
cursor = new UploadSessionCursor(sessionId, uploaded);
}
// (3) Finish
long remaining = size - uploaded;
CommitInfo commitInfo = CommitInfo.newBuilder(dropboxPath).withMode(WriteMode.ADD).withClientModified(new Date(localFile.lastModified())).build();
FileMetadata metadata = dbxClient.files().uploadSessionFinish(cursor, commitInfo).uploadAndFinish(in, remaining);
System.out.println(metadata.toStringMultiline());
return;
} catch (RetryException ex) {
thrown = ex;
// RetryExceptions are never automatically retried by the client for uploads. Must
// catch this exception even if DbxRequestConfig.getMaxRetries() > 0.
sleepQuietly(ex.getBackoffMillis());
continue;
} catch (NetworkIOException ex) {
thrown = ex;
// network issue with Dropbox (maybe a timeout?) try again
continue;
} catch (UploadSessionLookupErrorException ex) {
if (ex.errorValue.isIncorrectOffset()) {
thrown = ex;
// server offset into the stream doesn't match our offset (uploaded). Seek to
// the expected offset according to the server and try again.
uploaded = ex.errorValue.getIncorrectOffsetValue().getCorrectOffset();
continue;
} else {
// Some other error occurred, give up.
System.err.println("Error uploading to Dropbox: " + ex.getMessage());
System.exit(1);
return;
}
} catch (UploadSessionFinishErrorException ex) {
if (ex.errorValue.isLookupFailed() && ex.errorValue.getLookupFailedValue().isIncorrectOffset()) {
thrown = ex;
// server offset into the stream doesn't match our offset (uploaded). Seek to
// the expected offset according to the server and try again.
uploaded = ex.errorValue.getLookupFailedValue().getIncorrectOffsetValue().getCorrectOffset();
continue;
} else {
// some other error occurred, give up.
System.err.println("Error uploading to Dropbox: " + ex.getMessage());
System.exit(1);
return;
}
} catch (DbxException ex) {
System.err.println("Error uploading to Dropbox: " + ex.getMessage());
System.exit(1);
return;
} catch (IOException ex) {
System.err.println("Error reading from file \"" + localFile + "\": " + ex.getMessage());
System.exit(1);
return;
}
}
// if we made it here, then we must have run out of attempts
System.err.println("Maxed out upload attempts to Dropbox. Most recent error: " + thrown.getMessage());
System.exit(1);
}
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