public void setUploadId(String uploadId) {
        this.uploadId = uploadId;
    }
Sets the ID of the existing, initiated multipart upload with which this
new part will be associated.

@param uploadId
           the ID of the existing, initiated multipart upload with which
           this new part will be associated.
aws-java-sdk-s3/src/main/java/com/amazonaws/services/s3/model/UploadPartRequest.java