[JAVA] I want to use FireBase to display a timeline like Twitter

I want to display a timeline like Twitter

Since the data acquisition process of Firebase is an asynchronous process, when displaying the image and database data in a specific order like the Twitter timeline, if you display it without thinking, the image will shift, so the data will be recursively displayed. The recommended way is to get it.

java.Timeline.java

public class Timeline extends AppCompatActivity{

     //List to put the fetched database data
     private ArrayList<String> getDate = new ArrayList<>();
    
     //Get image reference
     private ArrayList<StorageReference> spaceRef = new ArrayList<>();

     //Create DatabaseReference object
     private DatabaseReference mDatabase;

     //FireBase storage
     private FirebaseStorage storage = FirebaseStorage.getInstance();

     //storage
     private StorageReference storageRef = storage.getReference();

    //Count variable
    private int Count = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

          //Get reference to Database
          mDatabase = FirebaseDatabase.getInstance().getReference();

          //FireBase Events
          mDatabase.addValueEventListener(new ValueEventListener() {
               @Override
               public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

                //Data you want to get
                Object getObject = postSnapshot.child(/*Data you want to get*/).getValue();

                //Null check of acquired data
                if(getObject != null) {

                       //Store in list
                       getDate.add(getObject .toString());

                       //Get image reference
                       spaceRef.add(storageRef.child(/*Reference image*/));

                       //Processing of the image you want to go to
                       getPhoto();

                }
          }
     }
    //Image acquisition
    private void getPhoto() {
        int Listsize = spaceRef.size();
        //Avoid looking off the list
        if(Count < Listsize) {
            final long ONE_MEGABYTE = 1024 * 1024;
            //Storage event
            spaceRef.get(Count).getBytes(ONE_MEGABYTE).addOnSuccessListener(new OnSuccessListener<byte[]>() {
                @Override
                public void onSuccess(byte[] bytes) {
                      //Thumbnail image acquisition
                      Bitmap bit = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);


                      /*Put the process to add to the list view*/

                      Count++;

                      getPhoto();

                }
            }).addOnFailureListener(new OnFailureListener() {
                @Override
                public void onFailure(@NonNull Exception exception) {
                }
            });
     }
}

The original list view has already been created, and I wrote it for those who are stumbling one step further, so it is quite appropriate (I think that the processing actually used is not helpful), but for the time being I managed to do it. .. Also, since it is java, I personally think that it is better to check null. My friend published it on Github, so I'll put a link on it. StutdentTimeline.java and TeacherStudent.java actually use this method. https://github.com/wasabimochi/ivycon When I feel like it, I'll write it neatly and post it (I'm not saying that). Please comment if you have any questions. see you.