Listing Streams

As described in the previous section, streams are scoped to the Amazon account associated with the Amazon credentials used to instantiate the Kinesis Data Streams client and also to the Region specified for the client. An Amazon account could have many streams active at one time. You can list your streams in the Kinesis Data Streams console, or programmatically. The code in this section shows how to list all the streams for your Amazon account.

ListStreamsRequest listStreamsRequest = new ListStreamsRequest();
listStreamsRequest.setLimit(20); 
ListStreamsResult listStreamsResult = client.listStreams(listStreamsRequest);
List<String> streamNames = listStreamsResult.getStreamNames();

This code example first creates a new instance of ListStreamsRequest and calls its setLimit method to specify that a maximum of 20 streams should be returned for each call to listStreams. If you do not specify a value for setLimit, Kinesis Data Streams returns a number of streams less than or equal to the number in the account. The code then passes listStreamsRequest to the listStreams method of the client. The return value listStreams is stored in a ListStreamsResult object. The code calls the getStreamNames method on this object and stores the returned stream names in the streamNames list. Note that Kinesis Data Streams might return fewer streams than specified by the specified limit even if there are more streams than that in the account and Region. To ensure that you retrieve all the streams, use the getHasMoreStreams method as described in the next code example.

while (listStreamsResult.getHasMoreStreams()) 
{
    if (streamNames.size() > 0) {
      listStreamsRequest.setExclusiveStartStreamName(streamNames.get(streamNames.size() - 1));
    }
    listStreamsResult = client.listStreams(listStreamsRequest);
    streamNames.addAll(listStreamsResult.getStreamNames());
}

This code calls the getHasMoreStreams method on listStreamsRequest to check if there are additional streams available beyond the ones returned in the initial call to listStreams. If so, the code calls the setExclusiveStartStreamName method with the name of the last stream that was returned in the previous call to listStreams. The setExclusiveStartStreamName method causes the next call to listStreams to start after that stream. The group of stream names returned by that call is then added to the streamNames list. This process continues until all the stream names have been collected in the list.

The streams returned by listStreams can be in one of the following states:

You can check the state of a stream using the describeStream method, as shown in the previous section, Creating a Stream via the APIs.