public String sasURL(String filePath) throws URISyntaxException, StorageException, InvalidKeyException {
CloudBlockBlob cloudBlockBlob = cloudBlobContainer.getBlockBlobReference(filePath);
SharedAccessBlobPolicy sasPolicy = new SharedAccessBlobPolicy();
GregorianCalendar calendar = new GregorianCalendar();
calendar.add(Calendar.HOUR, 3);
sasPolicy.setSharedAccessExpiryTime(calendar.getTime());
sasPolicy.setPermissions(EnumSet.of(SharedAccessBlobPermissions.READ, SharedAccessBlobPermissions.LIST));
SharedAccessBlobHeaders sharedAccessBlobHeaders = new SharedAccessBlobHeaders();
sharedAccessBlobHeaders.setContentType(MediaType.APPLICATION_PDF_VALUE);
String sas = cloudBlockBlob.generateSharedAccessSignature(sasPolicy, sharedAccessBlobHeaders,null);
return cloudBlockBlob.getUri()+"?"+sas;
}