我的应用程序中的重复用户聊天android

Question

“我为Android设计了一个聊天应用程序，我的代码有问题，发生的事情是用户重复，请如何纠正我的代码？”

这是有问题的代码，请帮助我修复此重复的用户，这是什么问题？请帮助我

    package com.developer.fireone.finga.Fragment;

import android.app.Activity;
import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.Fragment;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Adapter;

import com.developer.fireone.finga.Adapter.UserAdapter;
import com.developer.fireone.finga.Adapter.UserChatAdapter;
import com.developer.fireone.finga.Model.Chat;
import com.developer.fireone.finga.Model.ChatList;
import com.developer.fireone.finga.Model.User;
import com.developer.fireone.finga.Notifications.Token;
import com.developer.fireone.finga.R;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.Query;
import com.google.firebase.database.ValueEventListener;
import com.google.firebase.iid.FirebaseInstanceId;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;


public class ChatsFragment extends Fragment {

    private RecyclerView recyclerView;

    private UserChatAdapter userChatAdapter;

    private List <User> mUsers, newUserArrayList;

    FirebaseUser fuser;
    DatabaseReference reference;

    private List<String> usersList;



    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_chats, container, false);


        recyclerView = view.findViewById(R.id.recycler_view);
        recyclerView.setHasFixedSize(true);
        LinearLayoutManager linearLayoutManager=new LinearLayoutManager(getContext());
        linearLayoutManager.setReverseLayout(true);
        linearLayoutManager.setStackFromEnd(true);
        recyclerView.setLayoutManager(linearLayoutManager);

        fuser= FirebaseAuth.getInstance().getCurrentUser();

        usersList= new ArrayList<>();

        reference = FirebaseDatabase.getInstance().getReference("Chats");
        reference.keepSynced(true);
        reference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {

                usersList.clear();
             for(DataSnapshot snapshot : dataSnapshot.getChildren()){

                 Chat chat = snapshot.getValue(Chat.class);
                 if(chat.getSender().equals(fuser.getUid())) {
                     usersList.add(chat.getReceiver());
                 }

                 if(chat.getReceiver().equals(fuser.getUid())) {
                     usersList.add(chat.getSender());
                 }

             }

                readChats();


            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });

        updateToken(FirebaseInstanceId.getInstance().getToken());

        return view;
    }

    private void readChats() {

        mUsers = new ArrayList<>();
//Create a new list object
        newUserArrayList = new ArrayList<>();
        reference= FirebaseDatabase.getInstance().getReference("Users");

        reference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

                mUsers.clear();

                for(DataSnapshot snapshot : dataSnapshot.getChildren()){

                    User user = snapshot.getValue(User.class);

                    for(String id : usersList){
                        if(user.getId().equals(id)){
                            if(mUsers.size() != 0){
                                for(User user1 : mUsers){
                                    if(!user.getId().equals(user1.getId())){
                                        newUserArrayList.add(user);
                                        break;
                                    }
                                }
                            }else{
                                newUserArrayList.add(user);
                            }
                        }
                    }

                }

                userChatAdapter = new UserChatAdapter(getContext(), newUserArrayList, true);
                recyclerView.setAdapter(userChatAdapter);

            }

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

            }
        });
    }

复制图片：enter image description here 图片Firebase：enter image description here 我希望用户在发送或接收消息时出现在聊天框中一次