I do not receive Firebase data in the correct format

Question

Maybe something really stupid for me. But I do not receive bomb data in the correct format.

Person.java

public class Person {

    private String name;
    private String email;
    private String hobby;

    public Person(){

    }


    public Person(String name , String email , String hobby){
        this.name= name;
        this.email = email;
        this.hobby = hobby;

    }

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

    public void setEmail(String email) {
        this.email = email;
    }

    public void setHobby(String hobby) {
        this.hobby = hobby;
    }

    public String getName() {
        return name;
    }

    public String getEmail() {
        return email;
    }

    public String getHobby() {
        return hobby;
    }
}

MainActivity.java

public class MainActivity extends AppCompatActivity {

    private ViewPager viewPager;
//    private FirebaseAuth mAuth;
    List<Person> person;
    private Context context;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        person = new ArrayList<>();
//        mAuth = FirebaseAuth.getInstance();
        context = this;



        viewPager = (ViewPager) findViewById(R.id.pagerView);
        viewPager.setAdapter(new MyPagerAdapter(getSupportFragmentManager(), person, context));


    }


    class MyPagerAdapter extends FragmentPagerAdapter {
        String[] tabsArray;
        private List<Person> personInAdapter = new ArrayList<>();
        private Context context;

//        int icons[] = {R.drawable.white_home, R.drawable.white_heart,
//                R.drawable.white_star, R.drawable.white_heart, R.drawable.white_star};

        public MyPagerAdapter(FragmentManager fm, List<Person> person, Context context) {
            super(fm);
            personInAdapter = person;
            this.context = context;
            tabsArray = getResources().getStringArray(R.array.TABS);
        }


//        @Override
//        public CharSequence getPageTitle(int position) {
//            return tabsArray[position];
//        }

        @Override
        public Fragment getItem(int position) {

            return MyFragment.getInstance(position );
        }

        @Override
        public int getCount() {
            return personInAdapter.size();
        }
    }
}

MyFragment.java

public class MyFragment extends Fragment {
    private TextView upperText;
    private TextView lowerText;
    List<Person> personInAdapter = new ArrayList<>();
    private Context context;
    private DatabaseReference databaseReference;
    public static MyFragment getInstance(int position) {
        MyFragment myFragment = new MyFragment();
        Bundle args = new Bundle();
        args.putInt("position", position);
        myFragment.setArguments(args);

        return myFragment;
    }


    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_my, container, false);
        upperText = (TextView) view.findViewById(R.id.myFragmentUpperText);
        lowerText = (TextView) view.findViewById(R.id.myFragmentLowerText);
        databaseReference = FirebaseUtil.getBaseRef().child("Person");
        int i = getArguments().getInt("position");
         ValueEventListener postListener = new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                // Get Post object and use the values to update the UI
                Person person = dataSnapshot.getValue(Person.class);

                Log.e("Data In Person  ", person.toString());
                upperText.setText(person.getName());
                lowerText.setText(person.getEmail());
                // [END_EXCLUDE]
            }

            @Override
            public void onCancelled(DatabaseError databaseError) {
                // Getting Post failed, log a message
                // [START_EXCLUDE]

            }
        };
       databaseReference.addValueEventListener(postListener);
//        Bundle bundle = getArguments();
//        if (bundle != null) {
//            textView.setText("The value is" +i);
//        }

        return view;
    }


    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

    }
}

From LogCat:

 W/ClassMapper: No setter/field for -Ka45AN7nk3rAqTGfcp3 found on class testfirebase.com.testprojectforall.Person
 W/ClassMapper: No setter/field for -Ka45AN20cVBNFqbCwUj found on class testfirebase.com.testprojectforall.Person
 W/ClassMapper: No setter/field for -Ka45ANAi__pHJhzwjIa found on class testfirebase.com.testprojectforall.Person
 W/ClassMapper: No setter/field for -Ka45AN9pBd21aiHbS6i found on class testfirebase.com.testprojectforall.Person
 W/ClassMapper: No setter/field for -Ka45AN8Q1Y5GHOWRnpP found on class testfirebase.com.testprojectforall.Person
 E/Data In Person: testfirebase.com.testprojectforall.Person@b56a0f3
 W/ClassMapper: No setter/field for -Ka45AN7nk3rAqTGfcp3 found on class testfirebase.com.testprojectforall.Person
 W/ClassMapper: No setter/field for -Ka45AN20cVBNFqbCwUj found on class testfirebase.com.testprojectforall.Person
 W/ClassMapper: No setter/field for -Ka45ANAi__pHJhzwjIa found on class testfirebase.com.testprojectforall.Person
 W/ClassMapper: No setter/field for -Ka45AN9pBd21aiHbS6i found on class testfirebase.com.testprojectforall.Person
 W/ClassMapper: No setter/field for -Ka45AN8Q1Y5GHOWRnpP found on class testfirebase.com.testprojectforall.Person
 E/Data In Person: testfirebase.com.testprojectforall.Person@7dec1b0
 W/ClassMapper: No setter/field for -Ka45AN7nk3rAqTGfcp3 found on class testfirebase.com.testprojectforall.Person
 W/ClassMapper: No setter/field for -Ka45AN20cVBNFqbCwUj found on class testfirebase.com.testprojectforall.Person
 W/ClassMapper: No setter/field for -Ka45ANAi__pHJhzwjIa found on class testfirebase.com.testprojectforall.Person
 W/ClassMapper: No setter/field for -Ka45AN9pBd21aiHbS6i found on class testfirebase.com.testprojectforall.Person
 W/ClassMapper: No setter/field for -Ka45AN8Q1Y5GHOWRnpP found on class testfirebase.com.testprojectforall.Person
 E/Data In Person: testfirebase.com.testprojectforall.Person@6fc4829
 W/ClassMapper: No setter/field for -Ka45AN7nk3rAqTGfcp3 found on class testfirebase.com.testprojectforall.Person
 W/ClassMapper: No setter/field for -Ka45AN20cVBNFqbCwUj found on class testfirebase.com.testprojectforall.Person
 W/ClassMapper: No setter/field for -Ka45ANAi__pHJhzwjIa found on class testfirebase.com.testprojectforall.Person
 W/ClassMapper: No setter/field for -Ka45AN9pBd21aiHbS6i found on class testfirebase.com.testprojectforall.Person
 W/ClassMapper: No setter/field for -Ka45AN8Q1Y5GHOWRnpP found on class testfirebase.com.testprojectforall.Person
 E/Data In Person: testfirebase.com.testprojectforall.Person@3e83de5

Sample from my Firebase console:

I get the text, but cannot set it. What do I do when processing firebase requests?

Answer 1

You attach ValueEventListenerto Personnode in your database:

    ValueEventListener postListener = new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            // Get Post object and use the values to update the UI
            Person person = dataSnapshot.getValue(Person.class);

            Log.e("Data In Person  ", person.toString());
            upperText.setText(person.getName());
            lowerText.setText(person.getEmail());
            // [END_EXCLUDE]
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {
            // Getting Post failed, log a message
            // [START_EXCLUDE]

        }
    };
   databaseReference.addValueEventListener(postListener);

This means that your onDataChangewill be called with all the data in the Personnode. Therefore, in your case it will be several people.

In onDataChangeyou need to handle this by going through the child nodes in the snapshot:

public void onDataChange(DataSnapshot dataSnapshot) {
    for (DataSnapshot personSnapshot: dataSnapshot.getChildren()) {
        Person person = personSnapshot.getValue(Person.class);
        Log.i("Data In Person  ", person.toString());
    }
}