AWS S3 SDK ListObjectsV2 startafter 和 ContinuationToken 有什么区别？

Question

I'm using Aws::S3::Model::ListObjectsV2Request to list objects in AWS s3.

(It's c++ sdk, but I suppose the implementation is the same with Java, so if you're familiar with Java AWS S3 sdk pls also take a look at my question)

There're more than 1000 objects so can not fit in one page according to SDK 1000 records limit.

I found two API seems both reasonable to deal with this issue. 1.

// pseudo code
list_req
all_res = []
while true {
    res = list_req.request()
    all_res.add(res.get_all_entries())
    if (res.isTruncated()) {
        list_req.set_continuation_token(res.get_continuation_token());
    }
}

2.

// pseudo code
list_req
all_res = []
while true {
    res = list_req.request()
    all_res.add(res.get_all_entries())
    if (res.isTruncated()) {
        list_req.set_start_after(res.get_last_entry());
    }
}

What's the difference between these two approaches? (My situation is that I will get an exception with first approach The continuation token provided is incorrect with address : 52.218.217.49 , so I can only use the second one.)

Answer 1

StartAfter (string) -- StartAfter is where you want Amazon S3 to start listing from. Amazon S3 starts listing after this specified key. StartAfter can be any key in the bucket.

ContinuationToken (string) -- ContinuationToken indicates Amazon S3 that the list is being continued on this bucket with a token. ContinuationToken is obfuscated and is not a real key.

So, if you want to start listing a bucket from objects that begin with G , then use StartAfter = 'G' .

The ContinuationToken is used when more than 1000 results were returned. In such a case, the response provides a ContinuationToken that you must pass into the next call. The results will continue from where the last listing finished.

You can specify both of the parameters, if wanting to start at a particular name and retrieve more than 1000 objects.