How to sort my RecyclerView according to date and time

Question

As the image shows, my list is not being sorted according date and time

RecyclerView Image and this is my firebase structure

Firebase Image

Add Appointment.java -> this is how i add my data to firebase

  public class AddAppointment extends AppCompatActivity {

    private FirebaseAuth firebaseAuth;
    private FirebaseUser mCurrentUser;


    private EditText dateApp,timeApp,nameTxt,addressTxt,telTxt;
    int mYear,mMonth,mDay,mHour,mMinute;
    private Button saveBtn;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_add_appointment);
        Firebase.setAndroidContext(this);


        nameTxt = (EditText) findViewById(R.id.nameText);
        addressTxt= (EditText) findViewById(R.id.addressText);
        telTxt = (EditText) findViewById(R.id.telText);
        dateApp = (EditText)findViewById(R.id.dateAppointment);
        timeApp = (EditText)findViewById(R.id.timeAppointment);
        dateApp.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                datePic();
            }
        });
        timeApp.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                timePic();
            }
        });
        saveBtn = (Button)findViewById(R.id.saveBtn);
        saveBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                firebaseAuth = FirebaseAuth.getInstance();
                mCurrentUser = firebaseAuth.getCurrentUser();
                DatabaseReference db= FirebaseDatabase.getInstance().getReference().child("Email").child(mCurrentUser.getUid()).child("Appointment").push();
                String name = nameTxt.getText().toString().trim();
                String address = addressTxt.getText().toString().trim();
                String tel = telTxt.getText().toString().trim();
                String date = dateApp.getText().toString().trim();
                String time = timeApp.getText().toString().trim();

                //Adding values
                db.child("name").setValue(name);
                db.child("address").setValue(address);
                db.child("tel").setValue(tel);
                db.child("date").setValue(date);
                db.child("time").setValue(time);

                //Storing values to firebase
                Toast.makeText(AddAppointment.this,"Saved",Toast.LENGTH_SHORT).show();
                Intent mainIntent = new Intent(AddAppointment.this,MainActivity.class);
                startActivity(mainIntent);
            }
        });
    }
    public  void datePic()
    {
        final Calendar c = Calendar.getInstance();
        mYear = c.get(Calendar.YEAR);
        mMonth = c.get(Calendar.MONTH);
        mDay = c.get(Calendar.DAY_OF_MONTH);

        DatePickerDialog datePickerDialog = new DatePickerDialog(this,new DatePickerDialog.OnDateSetListener(){
            @Override
            public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth){
                mYear = year;
                mMonth = monthOfYear+1;
                mDay = dayOfMonth;
                dateApp.setText((mDay+"-"+mMonth+"-"+mYear));
            }
        },mDay,mMonth,mYear);
        datePickerDialog.getDatePicker().setMinDate(System.currentTimeMillis() - 1000);
        datePickerDialog.show();
    }
    public  void timePic()
    {
        final Calendar c = Calendar.getInstance();
        mHour = c.get(Calendar.HOUR_OF_DAY);
        mMinute = c.get(Calendar.MINUTE);

        TimePickerDialog timePickerDialog = new TimePickerDialog(this,new TimePickerDialog.OnTimeSetListener(){
            @Override
            public void onTimeSet(TimePicker view, int hourOfDay, int minute){
                int hour = hourOfDay % 12;
                timeApp.setText(String.format("%02d:%02d %s", hour == 0 ? 12 : hour,
                        minute, hourOfDay < 12 ? "a.m." : "p.m."));
            }
        },mHour,mMinute,false);
        timePickerDialog.show();
    }
}

AppointmentData.java -> this is my data setup

    public class AppointmentData {

    private String name,tel,address,time,date;

    public AppointmentData() {
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setTel(String tel) {
        this.tel = tel;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public void setTime(String time) {
        this.time = time;
    }

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

    public AppointmentData(String name, String tel, String address, String time, String date) {
        this.name=name;
        this.tel=tel;
        this.address=address;
        this.time=time;
        this.date=date;
    }

    public String getName() {
        return name;
    }

    public String getTel() {
        return tel;
    }

    public String getAddress() {
        return address;
    }

    public String getDate() {
        return date;
    }

    public String getTime() {
        return time;
    }

}

ViewAppointment.java -> this is how i display my recyclerview

 public class ViewAppointment extends AppCompatActivity {

    private FirebaseAuth firebaseAuth;
    private FirebaseUser mCurrentUser;
    private DatabaseReference db;
    private RecyclerView recyclerView;
    private FirebaseRecyclerAdapter<AppointmentData,myViewHolder> mAdapter;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_view_appointment);


        recyclerView=(RecyclerView)findViewById(R.id.recycle);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        firebaseAuth = FirebaseAuth.getInstance();

        mCurrentUser = firebaseAuth.getCurrentUser();
        db= FirebaseDatabase.getInstance().getReference().child("Email").child(mCurrentUser.getUid()).child("Appointment");
        db.keepSynced(true);
        mAdapter= new FirebaseRecyclerAdapter<AppointmentData, myViewHolder>(

                AppointmentData.class,R.layout.model,myViewHolder.class,db
        ) {


            @Override
            protected void populateViewHolder(final myViewHolder viewHolder, final AppointmentData model, final int position) {
                viewHolder.nameTxt.setText(model.getName());
                viewHolder.dateApp.setText(model.getDate());
                viewHolder.timeApp.setText(model.getTime());
                viewHolder.mapBtn.setText("Map");
                viewHolder.detailBtn.setText("Detail");
                viewHolder.deleteBtn.setText("Delete");
                viewHolder.editBtn.setText("Edit");
                Log.e("myFirebase UID", mAdapter.getRef(position).getKey());
                viewHolder.editBtn.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                        Intent i = new Intent (view.getContext(), UpdateAppointment.class);
                        i.putExtra("NAME_KEY",model.getName());
                        i.putExtra("ADDRESS_KEY",model.getAddress());
                        i.putExtra("TEL_KEY",model.getTel());
                        i.putExtra("DATE_KEY",model.getDate());
                        i.putExtra("TIME_KEY",model.getTime());
                        view.getContext().startActivity(i);
                        Log.e("Item Click position",""+position);
                        mAdapter.getRef(+position).removeValue();
                    }
                });
                viewHolder.detailBtn.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                        Intent i = new Intent (view.getContext(), DetailActivity.class);
                        i.putExtra("NAME_KEY",model.getName());
                        i.putExtra("ADDRESS_KEY",model.getAddress());
                        i.putExtra("TEL_KEY",model.getTel());
                        i.putExtra("DATE_KEY",model.getDate());
                        i.putExtra("TIME_KEY",model.getTime());
                        view.getContext().startActivity(i);
                    }
                });
                viewHolder.mapBtn.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                        Intent i = new Intent (view.getContext(), Distance.class);
                        i.putExtra("ADDRESS_KEY",model.getAddress());
                        view.getContext().startActivity(i);
                    }
                });
                viewHolder.deleteBtn.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                        Log.e("Item Click position",""+position);
                        mAdapter.getRef(+position).removeValue();
                    }
                });
            }
        };
        recyclerView.setAdapter(mAdapter);

    }
    public static class myViewHolder extends RecyclerView.ViewHolder{
        private TextView nameTxt,dateApp,timeApp;
        private Button detailBtn,mapBtn,deleteBtn,editBtn;

        public myViewHolder(View itemView){
            super(itemView);
            nameTxt=(TextView)itemView.findViewById(R.id.nameTxt);
            dateApp= (TextView) itemView.findViewById(R.id.dateAppointment);
            timeApp=(TextView)itemView.findViewById(R.id.timeAppointment);
            mapBtn = (Button) itemView.findViewById(R.id.mapBtn);
            detailBtn = (Button) itemView.findViewById(R.id.detailBtn);
            deleteBtn = (Button) itemView.findViewById(R.id.deleteBtn);
            editBtn = (Button) itemView.findViewById(R.id.editBtn);
        }
    }


}

Answer 1

you can use kotlin lamda with comparable interface to compare date to sort out list. first implement compareable interface in your list type model then use Collection.Sort(Listname)

vaccinationTypesList.sortWith { o1, o2 ->
    o1.vaccinationDate
      .compareTo(o2.vaccinationDate)
}

Answer 2

I had made a food delivery app and in which the order history is storing date wise as you can see Order History First just look at my database Database

now if you look my database carefully you will get the logic behind that.Logic is simple instead of using RandomUId = UUID.randomUUID().toString(); I had use RandomUId = getrandoumUID(); where getrandoumUID() is

public String getrandoumUID(){

    Calendar cr = Calendar.getInstance();
    SimpleDateFormat sdfr = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss");
    Date todayr = cr.getTime();
    String dater = sdfr.format(todayr);

    return dater;
}

When you are storing data to firebase instead of using random uid just use this method. Now when you retrive this data normally in recyclerview it will retrive in opposite order, to ensure that just add each item in the list at '0'th index

ArrayList.add(0,item);
adapter.notifyDataSetChanged();

Make sure to declare below steps in OnCreate() function

    recyclerView = findViewById(R.id.recyclerView);
    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(new LinearLayoutManager(Activity.this));
    ArrayList= new ArrayList<>();
    adapter = new Adapter(Activity.this,ArrayList);
    recyclerView.setAdapter(adapter);

Answer 3

Change make following changes to your AppointmentData

public class AppointmentData {
  // ...
  private Object date;
  // ...
  public void setDate(Object date) {
      this.date = date;
  }
  // ...
  public AppointmentData(String name, String tel, String address, String time, Object date) {
      // ...
  }
  // ...    
  public Object getDate() {
      return date;
  }
}

Change db to this:

Query db = FirebaseDatabase.getInstance().getReference().child("Email").child(mCurrentUser.getUid()).child("Appointment").orderByChild("date");

Change this line inside populateViewHolder to this: viewHolder.dateApp.setText(timestampToDateString(model.getDate()));

where timestampToDateString is a utility method:

public static String timestampToDateString(long timestamp){
    SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy");
    Date date = new Date(timestamp);
    return dateFormat.format(date);
}

change btnSave.onClickListener to this

    final String key = FirebaseDatabase.getInstance().getReference().child("Email").child(mCurrentUser.getUid()).child("Appointment").push().getKey();

    // ...
    Long date = mSelectedDate;
    // ...
    AppointmentData appointmentData = new AppointmentData(name, tel, address, time, date);

    FirebaseDatabase.getInstance().getReference().child("Email").child(mCurrentUser.getUid()).child("Appointment").child(key).setValue(appointmentData);
    // ...

add the field like so

private long mSelectedDate;

initialize it in datePic() like so

    // ...
    mYear = c.get(Calendar.YEAR);
    // ...
    mSelectedDate = fieldToTimestamp(mYear, mMonth, mDay);

and in onDateSelectedListener.onDateSet(...) like so

// ...
mSelectedDate = fieldToTimestamp(year, monthOfYear, dayOfMonth);

where fieldToTimestamp is helper method

private long fieldToTimestamp(int year, int month, int day) {
    Calendar calendar = Calendar.getInstance();
    calendar.set(Calendar.YEAR, year);
    calendar.set(Calendar.MONTH, month);
    calendar.set(Calendar.DAY_OF_MONTH, day);
    return (long) (calendar.getTimeInMillis() / 1000L);
}

I think that should be all of it.. Oh, and delete all your old Appointments so it doesn't cause exceptions.

Answer 4

This is sample which can solve your problem

// above i have store date in millisecond formate.

 ref.child("date").addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                ArrayList<Long> d = new ArrayList<>();
                for (DataSnapshot child : dataSnapshot.getChildren()) {
                  // save all millis in array list you can take your Bean class also
                    try {
                        long daa = Long.parseLong(child.getValue().toString());
                        d.add(daa);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
             // sort array list you can use comparator if you have bean class
                Collections.sort(d);
                for (int i = 0; i < d.size(); i++) {
                    String dateString = new SimpleDateFormat("dd-MM-yyyy").format(new Date(d.get(i)));
                    Log.e("!_@@ date", dateString + "");
                }
            }

        @Override
        public void onCancelled(FirebaseError firebaseError) {
            Log.e("!!__: ", "onCancelled ", firebaseError.toException());
        }
    });

output is :-

14-01-1970

26-01-1970

06-03-1970

14-04-1970