6

I use Java Redis client "Jedis".

When getting a sorted set using zrange for example, the client specifies it returns a Set which by definition has no oredering guarantee.

this old question mentions the problem but I have found no reference to whether it is resolved.

Can I do this and know order will be preserved?

Set<String> results = jedisCli.zrange(key, start, end);
MyObject[] requestedOrderedObjects = new MyObject[results.size];
int i = 0;
foreach(String result: results) {
    requestedOrderedObjects[i++] = MyObject.loadFromString(result);
}
return requestedOrderedObjects;

Thank you for any help.

Community
  • 1
  • 1
Daren
  • 3,337
  • 4
  • 21
  • 35

1 Answers1

6

Order is preserved, check the type of Set jedis returns: it is indeed a SortedSet and it is ordered. You are right: the API doesn't give you the hint it is ordered, but you should not be afraid: it works fine, or all my apps would have incredible bugs.

zenbeni
  • 7,019
  • 3
  • 29
  • 60
  • I had observed it to work fine, but since it is small tests in my local machine, i wasn't completely sure. Ina few months, another person trying to find the bug in when reproducibility is uncertain would have wrecked me. – Daren Apr 14 '14 at 10:42