CODEWITHSUNDEEP
javaspring-mvcforeachjava-8
Ah Hiang
Ah Hiang

Reputation: 592

Foreach java 8 from list of String to String

I have a member function that will retrieve all membershipId of a member(one member might have multiples of membershipId).After retrieve all membershipId using List,it will call the url like this.

This is my service:

RestRequest request = RestRequest.newBuilder()
                .url("/membership/" + membershipId + "/outlet")
                .get();

This is my controller:

 @RequestMapping(value = "/favouriteStores", method = RequestMethod.GET)
        public Object FavouriteStores(ModelMap modelMap,HttpSession session)throws  Exception {
          String memberId = "5677a7075e3f1b998fc7483b";


 List<Membership> membershipList= memberService.getMembershipByMemberId(memberId);

 List<String>  membershipIds = membershipList.stream().map(m->m.getId()).collect(Collectors.toList());
         String membershipId = membershipIds.toString();

        Set<Outlet> outletSet = membershipService.getOutletByMembershipId(membershipId);

My problem is it will transform the whole membershipId in one url like this "membership/[12345, 54321]/outlet" It should be two url like "membership/[12345]/outlet" and "membership/[54321]/outlet"

I know we can use foreach to do that in controller,but i don't know how.Thanks for any helps.

Upvotes: 0

Views: 280

Answers (1)

Mrinal
Mrinal

Reputation: 1906

Try map method of Stream instead : You can achieve this using map method of Stream.

Set<Outlet> outletSet = membershipIds.stream()
    .map(membershipService::getOutletByMembershipId)
    .collect(Collectors.toSet());

Even you can combine your previous stream operations and omit creation of intermediate list objects : 

String memberId = "5677a7075e3f1b998fc7483b";

Set<Outlet> outletSet = memberService.getMembershipByMemberId(memberId)
    .stream()
    .map(Membership::getId)
    .map(membershipService::getOutletByMembershipId)
    .collect(Collectors.toSet())

Upvotes: 3

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