@RequiredArgsConstructor
public class S3ObjectDelete {
    private AmazonS3Client client = new AmazonS3Client();

    private final String bucket;

    public static void main(String[] args) {
        val hoge = new S3ObjectDelete("Bucket name");
        hoge.delete("Prefix");
    }

    public void delete(String prefix) {
        //It seems that the maximum number of items that can be deleted at the same time is 1000, so divide and process
        for (val keys : Lists.partition(keys(prefix), 1000)) {
            String[] array = keys.toArray(new String[keys.size()]);
            client.deleteObjects(new DeleteObjectsRequest(bucket).withKeys(array));
        }
    }

    List<String> keys(String prefix) {
        ObjectListing objects = client.listObjects(bucket, prefix);
        val f = new S3Object2StringKey();
        List<String> keys = new ArrayList<>(Lists.transform(objects.getObjectSummaries(), f));

        //It seems that the default number of items that can be acquired at one time is 1000, so loop and acquire all
        while (objects.isTruncated()) {
            objects = client.listNextBatchOfObjects(objects);
            keys.addAll(Lists.transform(objects.getObjectSummaries(), f));
        }
        return keys;
    }
}

public static class S3Object2StringKey implements Function<S3ObjectSummary, String> {
    @Override
    public String apply(S3ObjectSummary input) {
        return input.getKey();
    }
}

Recommended Posts