get a list of unique date from the stream grouping

I have data:

id|date
1 |12-12-2021
2 |12-12-2021
3 |13-12-2021

Want to get a list of dates: ["12-12-2021", "13-12-2021"]

Using stream, I can get a map:

txs.stream().collect(Collectors.groupingBy(g -> g.getDate()));

I would like to convert to list in from the stream above.

>Solution :

groupingBy is not the best choice in your case. Use distinct instead. It will automatically filter out all duplicates.

txs.stream().map(g -> g.getDate()).distinct().collect(Collectors.toList());