合并两个不同对象的列表

Question

i'm using api requests that returns a list. -the first api request returns a list of object that contains (user_id,content,date,title) -the second response returns list of object too that contains (user_id,user_name).

i want to merge the two list the display them into one recycler view but keep user name instead of user_id.this image breaks down what i want clearly.

apprecuiate any help i'm really stuck in this and i need it ty .

EDIT

this is the first api call :

    followuplist=new ArrayList<>();


    Retrofit retrofit = RetrofitInstance.getRetrofitInstance();
    final Api api = retrofit.create(Api.class);
    Call<List<TraitementTicketModel>> call = api.getfollowup(id, sestoken);
    call.enqueue(new Callback<List<TraitementTicketModel>>() {

        @Override
        public void onResponse(Call<List<TraitementTicketModel>> call, Response<List<TraitementTicketModel>> response) {
            if (!response.isSuccessful()) {
                Toast.makeText(getApplicationContext(), "Something is wrong !! ", Toast.LENGTH_LONG).show();
                Log.e("TAG", "onResponse: something is wrong");


            } else if (response.body() == null) {

                return;
            }

            List<TraitementTicketModel> followups = response.body();


            for (TraitementTicketModel followup : followups) {


                followuplist.add(followup);

            }


            followuplist.add(firstfollowup());
           

        }

        @Override
        public void onFailure(Call<List<TraitementTicketModel>> call, Throwable t) {
            Toast.makeText(getApplicationContext(),"Pas de connextion internet",Toast.LENGTH_LONG).show();
        }
    });

this is the second api call :

      List<User> userList;
      SharedPreferences sp =getApplicationContext().getSharedPreferences("tokenPref", Context.MODE_PRIVATE);
    String sestoken = sp.getString("token","");

    Retrofit retrofit= RetrofitInstance.getRetrofitInstance();
    final Api api= retrofit.create(Api.class);
    Call<List<User>> call = api.getUser(sestoken);
    call.enqueue(new Callback<List<User>>() {
        @Override
        public void onResponse(Call<List<User>> call, Response<List<User>> response) {

            if (response.code() != 200){
                Log.e("TAG", "onResponse: something is wrong"+response.code() );



            }
            List<User> users = response.body();



            for (User user : users){

                userList.add(user);
            }

            swipeRefreshLayout.setRefreshing(false);



        }

so I have two liststhe first one is : followuplist (user_id,title,content,date) and the second : userList(user_id,user_name) but i didn't know what to do after that to get to my goal

Answer 1

You can do something like that. In this example UserDetails is the object on the left in your image, UserInfo the one on the right, and MergeData the result.

You should use Kotlin instead of Java, it's far easier to manipulate lists.

 List<MergedData> mergeList(
            List<UserDetails> listUserDetails,
            List<UserInfo> listUserInfo
    ) {

        // Resulting list
        final List<MergedData> result = new ArrayList<>();
        // We iterate through the first list
        for (UserDetails details : listUserDetails) {
            // For each element of the list we will try to find one with the same user id in the other list
            for (UserInfo info : listUserInfo) {
                // if the current element of the second list has the same user id as the current one from the first list, we merge the data in a new object and this object is then added to the result list.
                if (details.getUserId().equals(info.getUserId())) {
                    result.add(
                            new MergedData(
                               info.getName(),
                               details.getContent(),
                               details.getTitre(),
                               details.getDate()
                            )
                    );
                    // Once the object is found it is unnecessary to continue looping though the second list, so we break the for loop.
                    break;
                }
            }
        }
        // Once we finished to iterate through the first list, we return the result.
        return result;
    }

Same example in Kotlin:

fun mergeList(
    listUserDetails: List<UserDetails>,
    listUserInfo: List<UserInfo>
): List<MergedData> =
    listUserDetails.mapNotNull { details ->
        listUserInfo
            .firstOrNull { it.userId == details.userId }
            ?.let { info ->
                MergedData(
                    info.name,
                    details.content,
                    details.titre,
                    details.date
                )
            }
    }