Firestore Data Example

FirestoreDataExample.java

import android.annotation.SuppressLint;
import android.os.Bundle;

import com.google.firebase.firestore.DocumentSnapshot;
import com.google.firebase.firestore.EventListener;
import com.google.firebase.firestore.FirebaseFirestore;
import com.google.firebase.firestore.FirebaseFirestoreException;

import java.text.SimpleDateFormat;
import java.util.Date;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

public class FirestoreDataExample extends AppCompatActivity {
    private FirebaseFirestore db = FirebaseFirestore.getInstance();

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);


       db.collection("collectionName").document("documentId").addSnapshotListener(new EventListener<DocumentSnapshot>() {
            @Override
            public void onEvent(@Nullable DocumentSnapshot documentSnapshot, @Nullable FirebaseFirestoreException e) {
                if (documentSnapshot != null){

                    DataObj obj = documentSnapshot.toObject(DataObj.class);
                    assert obj != null;

                    //Server time stamp
                    long dateStamp = (long) documentSnapshot.get("createTime");
                    Date date = new Date(obj.getDate());


                    @SuppressLint("SimpleDateFormat")
                    SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd/MM/yy");


                    String dateText = simpleDateFormat.format(date);
                    System.out.println(dateText);
                }
            }
        });

    }

    private class DataObj {
        //Document fields
        private String id;
        private long date;


        //Mutators
        public String getId() {
            return id;
        }

        public void setId(String id) {
            this.id = id;
        }

        public long getDate() {
            return date;
        }

        public void setDate(long date) {
            this.date = date;
        }
    }
}