Spring Data MongoDB criteria with $in and list of regexes

Question

I've spotted MongoDb functionality that allows to find elements by a list of regexes using $in. Example:

db.inventory.find( { tags: { $in: [ /^be/, /^st/ ] } } )

And it works perfectly when typed directly to some Mongo tool as a query.

Now I'm trying to apply this query using spring-data-mongodb version 1.8.4.RELEASE. Example code:

List<Pattern> regexList = Arrays.asList(Pattern.compile("\\b5\\b"), Pattern.compile("\\b8\\b")); //regexes to find numbers 5 or 8 in string
Query query = new Query();
query.addCriteria(Criteria.where("key").in(regexList));

And it does not find anything, because query looks like this:

{"key" : { "$in" : [ { "$regex" : "\\b5\\b"} , { "$regex" : "\\b8\\b"}]}}}

First problem is the "$regex" that is not allowed in "$in" queries. Second problem is quotation marks that envelops regexes. I've also tried passing string list, but with no success either.

Am I missing something?

Answer 1

I had the same issue and finally found the below solution.

Query query = new Query();
query.addCriteria(Criteria.where("key").regex(searchString));

No need to use $in. $regex can search in the string as well as in the list of String. To search case insensitive substring add option "i".