Firebase-Datenbank Daten abrufen?

Question

Ich bin neu hier in Firebase meine Frage ist, wie man die Daten von Firebase holt das folgende Bild zeigt die Details meiner Datenbank.

Ich möchte die Daten von user_time_table in der Uid abrufen, da in jeder UID gibt es Savientage werden in jedem Tag angezeigt, es gibt Zeit und Steckplatz sind da ich möchte diese Schleppdaten in ListView abrufen und wie in der anzeigen Bild unten

, wie ich die Zeit von Firebase zu holen haben?

object class 





public String uid; 
    public String username; 
    public String address; 
    public String day; 
    public String slot; 
    public long time; 
    public int starCount = 0; 
    public Map<String, Boolean> stars = new HashMap<>(); 

    public drPost() { 
     // Default constructor required for calls to DataSnapshot.getValue(Post.class) 
    } 



    public drPost(String uid, String username, String address, String day, String slot, long time) { 
     this.uid = uid; 
     this.username = username; 
     this.address = address; 
     this.day = day; 
     this.slot = slot; 
     this.time = time; 
    } 

    // [START post_to_map] 
    @Exclude 
    public Map<String, Object> toMap() { 
     HashMap<String, Object> result = new HashMap<>(); 
     result.put("uid", uid); 
     result.put("address", address); 
     result.put("day", day); 
     result.put("slot", slot); 
     result.put("time", time); 
     result.put("starCount", starCount); 
     result.put("stars", stars); 

     return result; 
    } 
    // [END post_to_map] 
    public long getTime() { 
     return time; 
    } 

    public String getSlot(){ 
     return slot; 
    } 


    public String getDay(){ 
     return day; 
    } 



} 

// [END post_class]

/// und Blick holen ///

enter code here 


public class timetable extends Activity { 
    ListView listView, listView2; 
    List<drPost> drpostList = new ArrayList<>(); 
    // DatabaseReference databasetimeandslot; 
    DatabaseReference databaseReference; 

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


     databaseReference = FirebaseDatabase.getInstance().getReference().child("user_time_table").child("userID"); 

     // Get ListView object from xml 
     listView = (ListView) findViewById(R.id.list1); 

     listView2 = (ListView) findViewById(R.id.list1); 

     drpostList = new ArrayList<>(); 

     // Defined Array values to show in ListView 
     String[] values = new String[]{ 
       "Monday", 
       "Tuesday", 
       "Wednesday", 
       "Thursday", 
       "Friday", 
       "Saturday", 
       "Sunday" 

     }; 

     // Define a new Adapter 
     // First parameter - Context 
     // Second parameter - Layout for the row 
     // Third parameter - ID of the TextView to which the data is written 
     // Forth - the Array of data 

     ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, 
       R.layout.timetable_items, R.id.type, values); 


     // Assign adapter to ListView 
     listView.setAdapter(adapter); 

     // ListView Item Click Listener 
     listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 

      @Override 
      public void onItemClick(AdapterView<?> parent, View view, 
            int position, long id) { 


       // ListView Clicked item index 
       int itemPosition = position; 

       // ListView Clicked item value 
       String itemValue = (String) listView.getItemAtPosition(position); 

       Intent intent = new Intent(timetable.this, EditTimeTable.class); 
       intent.putExtra("key", itemValue); 
       startActivity(intent); 

       // Show Alert 
       Toast.makeText(getApplicationContext(), "" + itemValue, Toast.LENGTH_LONG).show(); 

      } 

     }); 
    } 




     @Override 
     protected void onStart() { 
      super.onStart(); 


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

        //clearing the previous artist list 
        drpostList.clear(); 

        //iterating through all the nodes 
        for (DataSnapshot postSnapshot : dataSnapshot.getChildren()) { 
         //getting artist 
         drPost drpost = postSnapshot.getValue(drPost.class); 
         //adding artist to the list 
         drpostList.add(drpost); 
        } 

        //creating adapter 
        timeandslot artistAdapter = new timeandslot(timetable.this, drpostList); 
        //attaching adapter to the listview 
        listView2.setAdapter(artistAdapter); 
       } 

       @Override 
       public void onCancelled(DatabaseError databaseError) { 

       } 
      }); 


     } 
    } 


enter code here 







    public class timeandslot extends ArrayAdapter<drPost> { 
     private Activity context; 
     List<drPost> drpost; 

     public timeandslot(Activity context, List<drPost> drpost) { 
      super(context, R.layout.timetable_items, drpost); 
      this.context = context; 
      this.drpost = drpost; 
     } 
    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     LayoutInflater inflater = context.getLayoutInflater(); 
     View listViewItem = inflater.inflate(R.layout.timetable_items, null, true); 

     // TextView version_TIME = (TextView) listViewItem.findViewById(R.id.version_TIME); 
     TextView version_SLOT = (TextView) listViewItem.findViewById(R.id.version_SLOT); 
     TextView Day = (TextView) listViewItem.findViewById(R.id.type); 

     drPost drposts = drpost.get(position); 
    // version_TIME.setText((int) drposts.getTime()); 
     version_SLOT.setText(drposts.getSlot()); 
     Day.setText(drposts.getDay()); 

     return listViewItem; 
    } 
} 

Answer 1

DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference(). 
       child("user_timetable"); 

databaseReference.child("uid").addChildEventListner(new ChildEventListener() 

    enter code here 

{ 

      @Override 
      public void onChildAdded(DataSnapshot dataSnapshot, String s) { 
       if (dataSnapshot != null && dataSnapshot.getValue() != null) 
        ObjectModel chat = dataSnapshot.getValue(ObjectModel.class); 
      } 

      public void onChildChanged(DataSnapshot dataSnapshot, String s) { 

      } 

      @Override 
      public void onChildRemoved(DataSnapshot dataSnapshot) { 

      } 

      @Override 
      public void onChildMoved(DataSnapshot dataSnapshot, String s) { 
      } 

      @Override 
      public void onCancelled(DatabaseError databaseError) { 

      } 
     });