Firebaseデータベースjava.util.ArrayList型の値を文字列に変換できません

Question

私のfirebaseデータベースにある家屋でリサイクラービューを使用することはできません。私がしようとしているのは、出発活動のすべての家を表示することですが、今は運がありません。ここに私が試したことがあります： 多くの行のコードで申し訳ありませんが、私はそれをよりよく説明するために完全なコードを表示したかったのです。 ONSTART（オン

）私はreyclerviewを移入しよう：しよう

/** 
* Created by nikos on 22/7/2017. 
*/ 

public class Houses { 
    private String availability; 
    private String city; 
    private String country; 
    private String description; 
    private Object fotos; 
    private String hid; 
    private String house_name; 
    private String langitude; 
    private String longitude; 
    private String mainFoto; 
    private String max_people; 
    private String price; 
    private String rating; 
    private String postalCode; 
    //Services 
    private String aircondition; 
    private String balcony; 
    private String breakfast; 
    private String cafe_bar_restaurant; 
    private String child_keeping; 
    private String clothes_laundry; 
    private String conference_rooms; 
    private String dinner; 
    private String doctor_support; 
    private String elevator; 
    private String hair_dryer; 
    private String in_room_safebox; 
    private String iron_ironing_board; 
    private String minibar; 
    private String newspaper_delivery; 
    private String parking; 
    private String private_bath; 
    private String reception_24; 
    private String room_service; 
    private String soundproof_walls; 
    private String wifi; 
    private String uid; 
    private Object user_reviews; 

    public Houses() { 
    } 

    public Houses(String availability, String city, String country, String description, Object fotos, String hid, String house_name, String langitude, String longitude, String mainFoto, String max_people, String price, String rating, String postalCode, String aircondition, String balcony, String breakfast, String cafe_bar_restaurant, String child_keeping, String clothes_laundry, String conference_rooms, String dinner, String doctor_support, String elevator, String hair_dryer, String in_room_safebox, String iron_ironing_board, String minibar, String newspaper_delivery, String parking, String private_bath, String reception_24, String room_service, String soundproof_walls, String wifi, String uid, Object user_reviews) { 
     this.availability = availability; 
     this.city = city; 
     this.country = country; 
     this.description = description; 
     this.fotos = fotos; 
     this.hid = hid; 
     this.house_name = house_name; 
     this.langitude = langitude; 
     this.longitude = longitude; 
     this.mainFoto = mainFoto; 
     this.max_people = max_people; 
     this.price = price; 
     this.rating = rating; 
     this.aircondition = aircondition; 
     this.balcony = balcony; 
     this.breakfast = breakfast; 
     this.cafe_bar_restaurant = cafe_bar_restaurant; 
     this.child_keeping = child_keeping; 
     this.clothes_laundry = clothes_laundry; 
     this.conference_rooms = conference_rooms; 
     this.dinner = dinner; 
     this.doctor_support = doctor_support; 
     this.elevator = elevator; 
     this.hair_dryer = hair_dryer; 
     this.in_room_safebox = in_room_safebox; 
     this.iron_ironing_board = iron_ironing_board; 
     this.minibar = minibar; 
     this.newspaper_delivery = newspaper_delivery; 
     this.parking = parking; 
     this.private_bath = private_bath; 
     this.reception_24 = reception_24; 
     this.room_service = room_service; 
     this.soundproof_walls = soundproof_walls; 
     this.wifi = wifi; 
     this.uid = uid; 
     this.user_reviews = user_reviews; 
     this.postalCode = postalCode; 
    } 

    public void setPostalCode(String postalCode) { 
     this.postalCode = postalCode; 
    } 

    public String getPostalCode() { 
     return postalCode; 
    } 

    public void setAvailability(String availability) { 
     this.availability = availability; 
    } 

    public void setCity(String city) { 
     this.city = city; 
    } 

    public void setCountry(String country) { 
     this.country = country; 
    } 

    public void setDescription(String description) { 
     this.description = description; 
    } 

    public void setFotos(Object fotos) { 
     this.fotos = fotos; 
    } 

    public void setHid(String hid) { 
     this.hid = hid; 
    } 

    public void setHouse_name(String house_name) { 
     this.house_name = house_name; 
    } 

    public void setLangitude(String langitude) { 
     this.langitude = langitude; 
    } 

    public void setLongitude(String longitude) { 
     this.longitude = longitude; 
    } 

    public void setMainFoto(String mainFoto) { 
     this.mainFoto = mainFoto; 
    } 

    public void setMax_people(String max_people) { 
     this.max_people = max_people; 
    } 

    public void setPrice(String price) { 
     this.price = price; 
    } 

    public void setRating(String rating) { 
     this.rating = rating; 
    } 

    public void setAircondition(String aircondition) { 
     this.aircondition = aircondition; 
    } 

    public void setBalcony(String balcony) { 
     this.balcony = balcony; 
    } 

    public void setBreakfast(String breakfast) { 
     this.breakfast = breakfast; 
    } 

    public void setCafe_bar_restaurant(String cafe_bar_restaurant) { 
     this.cafe_bar_restaurant = cafe_bar_restaurant; 
    } 

    public void setChild_keeping(String child_keeping) { 
     this.child_keeping = child_keeping; 
    } 

    public void setClothes_laundry(String clothes_laundry) { 
     this.clothes_laundry = clothes_laundry; 
    } 

    public void setConference_rooms(String conference_rooms) { 
     this.conference_rooms = conference_rooms; 
    } 

    public void setDinner(String dinner) { 
     this.dinner = dinner; 
    } 

    public void setDoctor_support(String doctor_support) { 
     this.doctor_support = doctor_support; 
    } 

    public void setElevator(String elevator) { 
     this.elevator = elevator; 
    } 

    public void setHair_dryer(String hair_dryer) { 
     this.hair_dryer = hair_dryer; 
    } 

    public void setIn_room_safebox(String in_room_safebox) { 
     this.in_room_safebox = in_room_safebox; 
    } 

    public void setIron_ironing_board(String iron_ironing_board) { 
     this.iron_ironing_board = iron_ironing_board; 
    } 

    public void setMinibar(String minibar) { 
     this.minibar = minibar; 
    } 

    public void setNewspaper_delivery(String newspaper_delivery) { 
     this.newspaper_delivery = newspaper_delivery; 
    } 

    public void setParking(String parking) { 
     this.parking = parking; 
    } 

    public void setPrivate_bath(String private_bath) { 
     this.private_bath = private_bath; 
    } 

    public void setReception_24(String reception_24) { 
     this.reception_24 = reception_24; 
    } 

    public void setRoom_service(String room_service) { 
     this.room_service = room_service; 
    } 

    public void setSoundproof_walls(String soundproof_walls) { 
     this.soundproof_walls = soundproof_walls; 
    } 

    public void setWifi(String wifi) { 
     this.wifi = wifi; 
    } 

    public void setUid(String uid) { 
     this.uid = uid; 
    } 

    public void setUser_reviews(Object user_reviews) { 
     this.user_reviews = user_reviews; 
    } 

    public String getAvailability() { 
     return availability; 
    } 

    public String getCity() { 
     return city; 
    } 

    public String getCountry() { 
     return country; 
    } 

    public String getDescription() { 
     return description; 
    } 

    public Object getFotos() { 
     return fotos; 
    } 

    public String getHid() { 
     return hid; 
    } 

    public String getHouse_name() { 
     return house_name; 
    } 

    public String getLangitude() { 
     return langitude; 
    } 

    public String getLongitude() { 
     return longitude; 
    } 

    public String getMainFoto() { 
     return mainFoto; 
    } 

    public String getMax_people() { 
     return max_people; 
    } 

    public String getPrice() { 
     return price; 
    } 

    public String getRating() { 
     return rating; 
    } 

    public String getAircondition() { 
     return aircondition; 
    } 

    public String getBalcony() { 
     return balcony; 
    } 

    public String getBreakfast() { 
     return breakfast; 
    } 

    public String getCafe_bar_restaurant() { 
     return cafe_bar_restaurant; 
    } 

    public String getChild_keeping() { 
     return child_keeping; 
    } 

    public String getClothes_laundry() { 
     return clothes_laundry; 
    } 

    public String getConference_rooms() { 
     return conference_rooms; 
    } 

    public String getDinner() { 
     return dinner; 
    } 

    public String getDoctor_support() { 
     return doctor_support; 
    } 

    public String getElevator() { 
     return elevator; 
    } 

    public String getHair_dryer() { 
     return hair_dryer; 
    } 

    public String getIn_room_safebox() { 
     return in_room_safebox; 
    } 

    public String getIron_ironing_board() { 
     return iron_ironing_board; 
    } 

    public String getMinibar() { 
     return minibar; 
    } 

    public String getNewspaper_delivery() { 
     return newspaper_delivery; 
    } 

    public String getParking() { 
     return parking; 
    } 

    public String getPrivate_bath() { 
     return private_bath; 
    } 

    public String getReception_24() { 
     return reception_24; 
    } 

    public String getRoom_service() { 
     return room_service; 
    } 

    public String getSoundproof_walls() { 
     return soundproof_walls; 
    } 

    public String getWifi() { 
     return wifi; 
    } 

    public String getUid() { 
     return uid; 
    } 

    public Object getUser_reviews() { 
     return user_reviews; 
    } 

    @Override 
    public String toString() { 
     return "Houses{" + 
       "availability='" + availability + '\'' + 
       ", city='" + city + '\'' + 
       ", country='" + country + '\'' + 
       ", description='" + description + '\'' + 
       ", fotos=" + fotos + 
       ", hid='" + hid + '\'' + 
       ", house_name='" + house_name + '\'' + 
       ", langitude='" + langitude + '\'' + 
       ", longitude='" + longitude + '\'' + 
       ", mainFoto='" + mainFoto + '\'' + 
       ", max_people='" + max_people + '\'' + 
       ", price='" + price + '\'' + 
       ", rating='" + rating + '\'' + 
       ", postalCode='" + postalCode + '\'' + 
       ", aircondition='" + aircondition + '\'' + 
       ", balcony='" + balcony + '\'' + 
       ", breakfast='" + breakfast + '\'' + 
       ", cafe_bar_restaurant='" + cafe_bar_restaurant + '\'' + 
       ", child_keeping='" + child_keeping + '\'' + 
       ", clothes_laundry='" + clothes_laundry + '\'' + 
       ", conference_rooms='" + conference_rooms + '\'' + 
       ", dinner='" + dinner + '\'' + 
       ", doctor_support='" + doctor_support + '\'' + 
       ", elevator='" + elevator + '\'' + 
       ", hair_dryer='" + hair_dryer + '\'' + 
       ", in_room_safebox='" + in_room_safebox + '\'' + 
       ", iron_ironing_board='" + iron_ironing_board + '\'' + 
       ", minibar='" + minibar + '\'' + 
       ", newspaper_delivery='" + newspaper_delivery + '\'' + 
       ", parking='" + parking + '\'' + 
       ", private_bath='" + private_bath + '\'' + 
       ", reception_24='" + reception_24 + '\'' + 
       ", room_service='" + room_service + '\'' + 
       ", soundproof_walls='" + soundproof_walls + '\'' + 
       ", wifi='" + wifi + '\'' + 
       ", uid='" + uid + '\'' + 
       ", user_reviews=" + user_reviews + 
       '}'; 
    } 

    @Exclude 
    public Map<String, Object> toMap() { 
     HashMap<String, Object> houseObject = new HashMap<>(); 

     houseObject.put("city", city); 
     houseObject.put("country", country); 
     houseObject.put("description", description); 
     houseObject.put("fotos", fotos); 
     houseObject.put("hid", hid); 
     houseObject.put("house_name", house_name); 
     houseObject.put("langitude", langitude); 
     houseObject.put("longitude", longitude); 
     houseObject.put("mainFoto", mainFoto); 
     houseObject.put("max_people", max_people); 
     houseObject.put("price", price); 
     houseObject.put("rating", rating); 
     houseObject.put("postalCode", postalCode); 
     houseObject.put("aircondition", aircondition); 
     houseObject.put("balcony", balcony); 
     houseObject.put("breakfast", breakfast); 
     houseObject.put("cafe_bar_restaurant", cafe_bar_restaurant); 
     houseObject.put("child_keeping", child_keeping); 
     houseObject.put("clothes_laundry", clothes_laundry); 
     houseObject.put("conference_rooms", conference_rooms); 
     houseObject.put("dinner", dinner); 
     houseObject.put("doctor_support", doctor_support); 
     houseObject.put("elevator", elevator); 
     houseObject.put("hair_dryer", hair_dryer); 
     houseObject.put("in_room_safebox", in_room_safebox); 
     houseObject.put("iron_ironing_board", iron_ironing_board); 
     houseObject.put("minibar", minibar); 
     houseObject.put("newspaper_delivery", newspaper_delivery); 
     houseObject.put("parking", parking); 
     houseObject.put("private_bath", private_bath); 
     houseObject.put("reception_24", reception_24); 
     houseObject.put("room_service", room_service); 
     houseObject.put("soundproof_walls", soundproof_walls); 
     houseObject.put("wifi", wifi); 
     houseObject.put("uid", uid); 
     houseObject.put("user_reviews", user_reviews); 

     return houseObject; 
    } 
} 

Answer 1

：

public class MainActivity extends AppCompatActivity 
      implements NavigationView.OnNavigationItemSelectedListener { 

    private FirebaseAuth mAuth; 
    private DatabaseReference mDatabase; 
    private DatabaseReference mDatabaseHouses; 

    private String uid; 
    private String email; 
    private String username; 

    private static final int RC_SIGN_IN = 123; 

    private RecyclerView mRecyclerView; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
     setSupportActionBar(toolbar); 

     mAuth = FirebaseAuth.getInstance(); 
     mDatabase = FirebaseDatabase.getInstance().getReference(); 
     mDatabaseHouses = FirebaseDatabase.getInstance().getReference().child("HOUSES"); 

     mRecyclerView = (RecyclerView) findViewById(R.id.main_recycler_houses); 
     mRecyclerView.setHasFixedSize(true); 
     mRecyclerView.setLayoutManager(new LinearLayoutManager(this)); 


     DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
     ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
       this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close); 
     drawer.setDrawerListener(toggle); 
     toggle.syncState(); 

     NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view); 
     navigationView.setNavigationItemSelectedListener(this); 
    } 

    @Override 
    protected void onStart() { 
     super.onStart(); 
     FirebaseUser currentUser = mAuth.getCurrentUser(); 
     if (currentUser == null) { 
      signUser(); 
     } 

     FirebaseRecyclerAdapter<Houses, HousesViewHolder> mHousesRecyclerAdapter = new FirebaseRecyclerAdapter<Houses, HousesViewHolder>(
       Houses.class, 
       R.layout.house_single, 
       HousesViewHolder.class, 
       mDatabaseHouses 
     ) { 
      @Override 
      protected void populateViewHolder(HousesViewHolder viewHolder, Houses house, int position) { 
       viewHolder.setHouseName(house.getHouse_name()); 
      } 
     }; 

     mRecyclerView.setAdapter(mHousesRecyclerAdapter); 
    } 

    private static class HousesViewHolder extends RecyclerView.ViewHolder { 
     View mView; 

     public HousesViewHolder(View itemView) { 
      super(itemView); 
      mView = itemView; 
     } 


     void setHouseName(String house_name) { 
      TextView house_name_tv = (TextView) mView.findViewById(R.id.single_house_name_tv); 
      house_name_tv.setText(house_name); 
     } 
    } 

    @Override 
    protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
     super.onActivityResult(requestCode, resultCode, data); 
     if (requestCode == RC_SIGN_IN) { 
      IdpResponse response = IdpResponse.fromResultIntent(data); 
      View parentLayout = findViewById(android.R.id.content); 

      // Successfully signed in 
      if (resultCode == RESULT_OK) { 
       final FirebaseUser signedUser = mAuth.getCurrentUser(); 
       ValueEventListener valueEventListener = new ValueEventListener() { 
        @Override 
        public void onDataChange(DataSnapshot dataSnapshot) { 
         if (!dataSnapshot.child(getString(R.string.users)).child(signedUser.getUid()).exists()) { 
          Log.d("SignInProcess", "onDataChange: **Register"); 
          uid = setNullToDefaultValue(signedUser.getUid()); 
          email = setNullToDefaultValue(signedUser.getEmail()); 
          User mUser = new User(); 
          mUser.setUid(uid); 
          mUser.setEmail(email); 
          Map<String, Object> userMap = mUser.userToMap(); 
          userMap.put("date", Calendar.getInstance().getTime().toString()); 
          mDatabase.child(getString(R.string.users)).child(mAuth.getCurrentUser().getUid()).updateChildren(userMap).addOnCompleteListener(new OnCompleteListener<Void>() { 
           @Override 
           public void onComplete(@NonNull Task<Void> task) { 
            startActivity(new Intent(MainActivity.this, ChooseUsernameActivity.class)); 
            finish(); 
           } 
          }); 
         } else { 
          Log.d("SignInProcess", "onDataChange: **Log In"); 
         } 
        } 

        @Override 
        public void onCancelled(DatabaseError databaseError) { 

        } 
       }; 
       mDatabase.addValueEventListener(valueEventListener); 
       Snackbar.make(parentLayout, "You Signed In!", Snackbar.LENGTH_LONG); 
       startActivity(new Intent(MainActivity.this, MainActivity.class)); 
       finish(); 
       return; 
      } else { 
       // Sign in failed 
       if (response == null) { 
        // User pressed back button 
        Snackbar.make(parentLayout, "User presses back", Snackbar.LENGTH_LONG); 
        return; 
       } 

       if (response.getErrorCode() == ErrorCodes.NO_NETWORK) { 
        Snackbar.make(parentLayout, "No Network", Snackbar.LENGTH_LONG); 
        return; 
       } 

       if (response.getErrorCode() == ErrorCodes.UNKNOWN_ERROR) { 
        Snackbar.make(parentLayout, "Unknown Error", Snackbar.LENGTH_LONG); 
        return; 
       } 
      } 

     } 
    } 

    @Override 
    public void onBackPressed() { 
     DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
     if (drawer.isDrawerOpen(GravityCompat.START)) { 
      drawer.closeDrawer(GravityCompat.START); 
     } else { 
      super.onBackPressed(); 
     } 
    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.main, menu); 
     return true; 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     // Handle action bar item clicks here. The action bar will 
     // automatically handle clicks on the Home/Up button, so long 
     // as you specify a parent activity in AndroidManifest.xml. 
     int id = item.getItemId(); 

     //noinspection SimplifiableIfStatement 
     if (id == R.id.action_log_out) { 
      AuthUI.getInstance() 
        .signOut(MainActivity.this) 
        .addOnCompleteListener(new OnCompleteListener<Void>() { 
         @Override 
         public void onComplete(@NonNull Task<Void> task) { 
          mAuth = FirebaseAuth.getInstance(); 
          FirebaseUser currentUser = mAuth.getCurrentUser(); 
          if (currentUser == null) { 
           signUser(); 
          } 
         } 
        }); 
      return true; 
     } 

     return super.onOptionsItemSelected(item); 
    } 

    private void signUser() { 
     startActivityForResult(
       AuthUI.getInstance() 
         .createSignInIntentBuilder() 
         .setTheme(R.style.DarkTheme) 
//       .setLogo(R.mipmap.ic_launcher) 
         .setIsSmartLockEnabled(true) 
         .setAvailableProviders(
           Arrays.asList(
             new AuthUI.IdpConfig.Builder(AuthUI.EMAIL_PROVIDER).build(), 
             new AuthUI.IdpConfig.Builder(AuthUI.PHONE_VERIFICATION_PROVIDER).build() 
           )) 
         .build(), 
       RC_SIGN_IN); 
    } 

    @SuppressWarnings("StatementWithEmptyBody") 
    @Override 
    public boolean onNavigationItemSelected(MenuItem item) { 
     // Handle navigation view item clicks here. 
     int id = item.getItemId(); 

     if (id == R.id.nav_home) { 
      startActivity(new Intent(MainActivity.this, MainActivity.class)); 
      return true; 
     } else if (id == R.id.nav_profile) { 
      startActivity(new Intent(MainActivity.this, ProfileActivity.class)); 
      return true; 
     } else if (id == R.id.nav_settings) { 
      startActivity(new Intent(MainActivity.this, SettingsActivity.class)); 
      return true; 
     } 
     DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
     drawer.closeDrawer(GravityCompat.START); 
     return true; 
    } 

    //Database Housekeeping 
    public String setNullToDefaultValue(String s) { 
     String defaultValue = "default_value"; 
     if (s == null) 
      return defaultValue; 
     return s; 
    } 
} 

そして、ここでは、私がgetHouse_name（）メソッドを使用して、そこからモデルクラスでありますこのコードのようなものを使用する

DatabaseReference mDatabase; 

mDatabase = FirebaseDatabase.getInstance().getReference(); 
mDatabase.child("HOUSES").addChildEventListener(new ChildEventListener() { 
      @Override 
      public void onChildAdded(DataSnapshot dataSnapshot, String s) { 


       Map<String, String> map = (Map<String, String>) dataSnapshot.getValue(); 

       Houses model = new Houses(map.get("key_name"), map.get("key_name"),......); 

       adapter.addItem(model); 
       progressDialog.dismiss(); 
      } 

      @Override 
      public void onChildChanged(DataSnapshot dataSnapshot, String s) { 

      } 

      @Override 
      public void onChildRemoved(DataSnapshot dataSnapshot) { 

      } 

      @Override 
      public void onChildMoved(DataSnapshot dataSnapshot, String s) { 

      } 

      @Override 
      public void onCancelled(DatabaseError databaseError) { 
       progressDialog.dismiss(); 
       Toast.makeText(FetchData.this, "Something went wrong -> " + databaseError, Toast.LENGTH_LONG).show(); 
      } 
     });