How to crawl a s3 bucket for new files

Question

如何抓取s3存储桶以确保是否有任何新文件或对象添加或删除了？

Answer 1

Now you can get a message when there is a change. This was just announced (long overdue):
http://aws.amazon.com/blogs/aws/s3-event-notification/

It is very simple to implement - time to throw out all the ugly cron jobs and list-loops.

Answer 2

By usin Java AWS SDK, able to connect to S3 bucket from Java and able to crawl the bucket.

Crawling is nothing but taking the objects in a list and comparing and identifying the new object.

Example can be found in http://aws.amazon.com/sdk-for-java/