Upload a File

The following example shows how to use the low-level Java classes to upload a file. It performs the following steps:

• Initiates a multipart upload using the AmazonS3Client.initiateMultipartUpload() method, and passes in an InitiateMultipartUploadRequest object.
• Saves the upload ID that the AmazonS3Client.initiateMultipartUpload() method returns. You provide this upload ID for each subsequent multipart upload operation.
• Uploads the parts of the object. For each part, you call the AmazonS3Client.uploadPart() method. You provide part upload information using an UploadPartRequest object.
• For each part, saves the ETag from the response of the AmazonS3Client.uploadPart() method in a list. You use the ETag values to complete the multipart upload.
• Calls the AmazonS3Client.completeMultipartUpload() method to complete the multipart upload.

Example
For instructions on creating and testing a working sample, see Testing the Amazon S3 Java Code Examples.

import com.amazonaws.AmazonServiceException;

import com.amazonaws.SdkClientException;

import com.amazonaws.auth.profile.ProfileCredentialsProvider;

import com.amazonaws.regions.Regions;

import com.amazonaws.services.s3.AmazonS3;

import com.amazonaws.services.s3.AmazonS3ClientBuilder;

import com.amazonaws.services.s3.model.*;

import java.io.File;

import java.io.IOException;

import java.util.ArrayList;

import java.util.List;

public class LowLevelMultipartUpload {

public static void main(String[] args) throws IOException {

Regions clientRegion = Regions.DEFAULT_REGION;

String bucketName = "*** Bucket name ***";

String keyName = "*** Key name ***";

String filePath = "*** Path to file to upload ***";

File file = new File(filePath);

long contentLength = file.length();

long partSize = 5 * 1024 * 1024; // Set part size to 5 MB.

try {

AmazonS3 s3Client = AmazonS3ClientBuilder.standard()

.withRegion(clientRegion)

.withCredentials(new ProfileCredentialsProvider())

.build();

// Create a list of ETag objects. You retrieve ETags for each object part uploaded,

// then, after each individual part has been uploaded, pass the list of ETags to

// the request to complete the upload.

List<PartETag> partETags = new ArrayList<PartETag>();

// Initiate the multipart upload.

InitiateMultipartUploadRequest initRequest = new InitiateMultipartUploadRequest(bucketName, keyName);

InitiateMultipartUploadResult initResponse = s3Client.initiateMultipartUpload(initRequest);

// Upload the file parts.

long filePosition = 0;

for (int i = 1; filePosition < contentLength; i++) {

// Because the last part could be less than 5 MB, adjust the part size as needed.

partSize = Math.min(partSize, (contentLength - filePosition));

// Create the request to upload a part.

UploadPartRequest uploadRequest = new UploadPartRequest()

.withBucketName(bucketName)

.withKey(keyName)

.withUploadId(initResponse.getUploadId())

.withPartNumber(i)

.withFileOffset(filePosition)

.withFile(file)

.withPartSize(partSize);

// Upload the part and add the response's ETag to our list.

UploadPartResult uploadResult = s3Client.uploadPart(uploadRequest);

partETags.add(uploadResult.getPartETag());

filePosition += partSize;

}

// Complete the multipart upload.

CompleteMultipartUploadRequest compRequest = new CompleteMultipartUploadRequest(bucketName, keyName,

initResponse.getUploadId(), partETags);

s3Client.completeMultipartUpload(compRequest);

} catch (AmazonServiceException e) {

// The call was transmitted successfully, but Amazon S3 couldn't process

// it, so it returned an error response.

e.printStackTrace();

} catch (SdkClientException e) {

// Amazon S3 couldn't be contacted for a response, or the client

// couldn't parse the response from Amazon S3.

e.printStackTrace();

}

}

}