AWS S3 multipart file upload with public access

1. import java.io.File;
2. import java.io.IOException;
3. import java.util.ArrayList;
4. import java.util.List;
5. 
   
6. import com.amazonaws.auth.profile.ProfileCredentialsProvider;
7. import com.amazonaws.services.s3.AmazonS3;
8. import com.amazonaws.services.s3.AmazonS3Client;
9. import com.amazonaws.services.s3.model.AbortMultipartUploadRequest;
10. import com.amazonaws.services.s3.model.CannedAccessControlList;
11. import com.amazonaws.services.s3.model.CompleteMultipartUploadRequest;
12. import com.amazonaws.services.s3.model.InitiateMultipartUploadRequest;
13. import com.amazonaws.services.s3.model.InitiateMultipartUploadResult;
14. import com.amazonaws.services.s3.model.PartETag;
15. import com.amazonaws.services.s3.model.UploadPartRequest;
17. public class MultipartPublicFileUpload {
19.     static AmazonS3 s3Client = new AmazonS3Client(new ProfileCredentialsProvider());
21.     static public boolean multiPartFileUploadWithPublicAccess(String existingBucketName, String keyName, String filePath) {
22.         // Create a list of UploadPartResponse objects. You get one of these
23.         // for each part upload.
24.         List<PartETag> partETags = new ArrayList<PartETag>();
26.         // Step 1: Initialize.
27.         InitiateMultipartUploadRequest initRequest = new InitiateMultipartUploadRequest(existingBucketName, keyName);
28.         initRequest.setCannedACL(CannedAccessControlList.PublicRead);//This is where we are enabling this file for public access
29.         InitiateMultipartUploadResult initResponse
30.             = s3Client.initiateMultipartUpload(initRequest);
32.         File file = new File(filePath);
33.         long contentLength = file.length();
34.         long partSize = 5242880; // Set part size to 5 MB.
36.         try {
37.             // Step 2: Upload parts.
38.             long filePosition = 0;
39.             for (int i = 1; filePosition < contentLength; i++) {
40.                 // Last part can be less than 5 MB. Adjust part size.
41.                 partSize = Math.min(partSize, (contentLength - filePosition));
43.                 // Create request to upload a part.
44.                 UploadPartRequest uploadRequest = new UploadPartRequest()
45.                     .withBucketName(existingBucketName).withKey(keyName)
46.                     .withUploadId(initResponse.getUploadId()).withPartNumber(i)
47.                     .withFileOffset(filePosition)
48.                     .withFile(file)
49.                     .withPartSize(partSize);
51.                 // Upload part and add response to our list.
52.                 partETags.add(
53.                     s3Client.uploadPart(uploadRequest).getPartETag());
55.                 filePosition += partSize;
56.             }
58.             // Step 3: Complete.
59.             CompleteMultipartUploadRequest compRequest = new CompleteMultipartUploadRequest(
60.                 existingBucketName,
61.                 keyName,
62.                 initResponse.getUploadId(),
63.                 partETags);
65.             s3Client.completeMultipartUpload(compRequest);
66.             return true;
67.         } catch (Exception e) {
68.             s3Client.abortMultipartUpload(new AbortMultipartUploadRequest(
69.                 existingBucketName, keyName, initResponse.getUploadId()));
70.             return false;
71.         }
72.     }
74.     public static void main(String[] args) throws IOException {
75.         String existingBucketName = "myphotowall";
76.         String keyName = "photo/myuploadedtestfile3.txt";
77.         String filePath = "/tmp/mytestfile.txt";
78.         multiPartFileUploadWithPublicAccess(existingBucketName, keyName, filePath);
80.     }
81. }

Before you run make sure you have setup the API clients crendentials properly.See http://mohiplanet.blogspot.com/2014/12/setting-up-aws-s3-api-java-client.html

Note * : This will upload file with content type application/x-www-form-urlencoded; charset=utf-8

Please refer to http://mohiplanet.blogspot.com/2014/12/amazon-web-services-s3-api-java-client.html for updating keys with correct content type or setting correct content type with object metadata while uploading.

References :
http://docs.aws.amazon.com/AmazonS3/latest/dev/llJavaUploadFile.html