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I want to get the values from firebase, but I get this error, where is the problem?

private RecyclerView recyclerView;
    private CamperSiteAdapter camperSiteAdapter;
    private List<CamperSiteModel> camperSiteModel;
    EditText seatch_bar;


private void readCampSite(){
        DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Campsite");
        reference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                if(seatch_bar.getText().toString().equals("")){
                    camperSiteModel.clear();
                    for(DataSnapshot snapshot : dataSnapshot.getChildren()){
                        CamperSiteModel camperSiteModel1 = snapshot.getValue(CamperSiteModel.class);
                        camperSiteModel.add(camperSiteModel1);
                    }
                    camperSiteAdapter.notifyDataSetChanged();
                }
            }

            @Override
            public void onCancelled(@NonNull DatabaseError error) {

            }
        });
    }

this is model code

 public CamperSiteModel() {
    }

    public CamperSiteModel(String camperSiteID, String camperSiteName, String camperSiteImage, String camperSiteType, String camperSiteDistance, String camperSiteInfo, String camperSiteSummary, String camperSiteAddress, String camperSiteLatitude, String camperSiteLongitude, String camperSitePrice1, String camperSitePrice2, String camperSiteEmail, String camperSiteSub) {
        CamperSiteID = camperSiteID;
        CamperSiteName = camperSiteName;
        CamperSiteImage = camperSiteImage;
        CamperSiteType = camperSiteType;
        CamperSiteDistance = camperSiteDistance;
        CamperSiteInfo = camperSiteInfo;
        CamperSiteSummary = camperSiteSummary;
        CamperSiteAddress = camperSiteAddress;
        CamperSiteLatitude = camperSiteLatitude;
        CamperSiteLongitude = camperSiteLongitude;
        CamperSitePrice1 = camperSitePrice1;
        CamperSitePrice2 = camperSitePrice2;
        CamperSiteEmail = camperSiteEmail;
        CamperSiteSub = camperSiteSub;
    }

this is the firebase database

Campsite
    CamperSiteAddress: "90 Tasman Hwy, Orford TAS 7190"
    CamperSiteDistance: ""
    CamperSiteEmail: ""
    CamperSiteImage: "https://media-cdn.tripadvisor.com/media/photo-s..."
    CamperSiteInfo: "Raspins Beach"
    CamperSiteLatitude: ""
    CamperSiteLongitude: ""
    CamperSiteName: "Raspins Beach"
    CamperSitePrice1: "free"
    CamperSitePrice2: "free"
    CamperSiteSub: "TAS"
    CamperSiteSummary: "Raspins Beach"
    CamperSiteType: "Camp"

I don't know why this line was an error.

have I missed something? or where is the error?

is the model problem? or somewhere?

CamperSiteModel camperSiteModel1 = snapshot.getValue(CamperSiteModel.class);

error log

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.luvtas.campingau, PID: 11763
    com.google.firebase.database.DatabaseException: Can't convert object of type java.lang.String to type com.luvtas.campingau.Model.CamperSiteModel
        at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertBean(CustomClassMapper.java:436)
        at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToClass(CustomClassMapper.java:232)
        at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertToCustomClass(CustomClassMapper.java:80)
        at com.google.firebase.database.DataSnapshot.getValue(DataSnapshot.java:203)
        at com.luvtas.campingau.Fragment.ExploreFragment$3.onDataChange(ExploreFragment.java:128)
        at com.google.firebase.database.core.ValueEventRegistration.fireEvent(ValueEventRegistration.java:75)
        at com.google.firebase.database.core.view.DataEvent.fire(DataEvent.java:63)
        at com.google.firebase.database.core.view.EventRaiser$1.run(EventRaiser.java:55)
        at android.os.Handler.handleCallback(Handler.java:790)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6494)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
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  • can you share the error log as well please? Commented Mar 6, 2021 at 18:02
  • @MehranB update into the text Commented Mar 6, 2021 at 18:07
  • is your value saved all in one string in firebase ? i'd suggest you get it as string then pass it to your constructor to create your needed object Commented Mar 6, 2021 at 18:28

1 Answer 1

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Remove the for loop, since when you are looping you are retrieving the values of type String and not of the model class:

if(seatch_bar.getText().toString().equals("")){
  camperSiteModel.clear();
  CamperSiteModel camperSiteModel1 = dataSnapshot.getValue(CamperSiteModel.class);
  camperSiteModel.add(camperSiteModel1);
  camperSiteAdapter.notifyDataSetChanged();
  }

Also in your database add a push id after the node Campsite, and you need to follow the javabean convention

The class properties must be accessible using get, set, is (can be used for boolean properties instead of get), to and other methods (so-called accessor methods and mutator methods) according to a standard naming convention. This allows easy automated inspection and updating of bean state within frameworks, many of which include custom editors for various types of properties. Setters can have one or more than one argument.

You need to follow the camelCase naming convention to be able to map the database fields to the model class.

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