java - spring-data-mongodb optional query parameter -

i using spring-data-mongodb.

i want query database passing optional parameter in query.

i have domain class.

public class doc {       @id     private string id;      private string type;      private string name;      private int index;        private string data;      private string description;      private string key;      private string username;     // getter & setter } 

my controller:

@requestmapping(value = "/getbycategory", method = requestmethod.get, consumes = mediatype.application_json, produces = mediatype.application_json)     public iterable<doc> getbycategory(             @requestparam(value = "key", required = false) string key,             @requestparam(value = "username", required = false) string username,             @requestparam(value = "page", required = false, defaultvalue = "0") int page,             @requestparam(value = "size", required = false, defaultvalue = "0") int size,             @requestparam(value = "categories") list<string> categories)             throws entitynotfoundexception {         iterable<doc> nodes = docservice.getbycategory(key, username , categories, page, size);         return nodes;     } 

here key , username optional query parameters.

if pass 1 of them should return matching document given key or username.

my service method is:

public iterable<doc> getbycategory(string key, string username, list<string> categories, int page, int size) {          return repository.findbycategories(key, username, categories, new pagerequest(page, size));     } 

repository:

@query("{ $or : [ {'key':?0},{'username':?1},{categories:{$in: ?2}}] }")     list<doc> findbycategories(string key, string username,list<string> categories, pageable pageable); 

but using above query not returns document either given key or username. wrong in query?

this how making request http://localhost:8080/document/getbycategory?key=key_one&username=ppotdar&categories=category1&categories=category2

personally, i'd ditch interface-driven repository pattern @ point, create dao @autowires mongotemplate object, , query db using criteria instead. way, have clear code isn't stretching capabilities of @query annotation.

so, (untested, pseudo-code):

@repository public class docdaoimpl implements docdao {     @autowired private mongotemplate mongotemplate;      public page<doc> findbycategories(userrequest request, pageable pageable){         //go through user request , make criteria here         criteria c = criteria.where("foo").is(bar).and("x").is(y);          query q = new query(c);         long count = mongotemplate.count(q);          // following can refactored method, given query , pageable.         q.with(sort); //build sort pageable.         q.limit(limit); //build pageable         list<doc> results = mongotemplate.find(q, doc.class);         return makepage(results, pageable, count);     }      ... } 

i know flies in face of trend towards runtime generation of db code, mind, it's still best approach more challenging db operations, because it's loads easier see what's going on.