Fathy Eldesouky:

i have spent maybe 4 days and watched 100 videos about this issue , its my first question here on stackoverflow and also it is my first application ever i hope someone will help me this is my Login activity which i included the Facebook login for :

public class LoginActivity extends AppCompatActivity  {
Button createaccount;
Button login;
private FirebaseAuth mAuth;
ProgressBar progressBar;
public static final String EXTRA_MESSAGE = "com.fathy.reufamnew.MESSAGE";
TextView testys;
private EditText mEmailView;
private EditText mPasswordView;
LoginButton facebutton;
ImageView imgavatar;
CallbackManager callbackManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    callbackManager=CallbackManager.Factory.create();
    setContentView(R.layout.activity_login);
    login=(Button)findViewById(R.id.login);
    mAuth=FirebaseAuth.getInstance();
    facebutton=(LoginButton)findViewById(R.id.fb_login);
    testys=(TextView)findViewById(R.id.testys) ;
    progressBar=(ProgressBar)findViewById(R.id.progressbar);
    mEmailView = (EditText) findViewById(R.id.emailnow);
    mPasswordView = (EditText) findViewById(R.id.password1);

    facebutton.setReadPermissions(Arrays.asList("public_profile","email","user_birthday","user_hometown","user_about_me"));
    facebutton.registerCallback(callbackManager, new FacebookCallback () {
        @Override
        public void onSuccess(LoginResult loginResult) {

            String  accesstoken =loginResult.getAccessToken().getToken();
            GraphRequest request = GraphRequest.newMeRequest(loginResult.getAccessToken(), new GraphRequest.GraphJSONObjectCallback() {

                @Override
                public void onCompleted(JSONObject object, GraphResponse response) {
                    Intent intent=new Intent(LoginActivity.this,Facebook.class);
                    intent.putExtra("object",object.toString());
                    startActivity(intent);

                    Log.v("response", response.toString());
                }
            });
            Bundle parameters = new Bundle();
            parameters.putString("fields", "id, first_name, age_range,last_name, email, birthday, gender,location.fields(location)"); // Parámetros que pedimos a facebook
            request.setParameters(parameters);
            request.executeAsync();
            testys.setText("Login Sucess\n"+loginResult.getAccessToken().getUserId());
        }

        @Override
        public void onCancel() {
            testys.setText("login canceled");
        }

        @Override
        public void onError(FacebookException error) {

        }
    });
}



@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    callbackManager.onActivityResult(requestCode,resultCode,data);
}


private void attemptLogin() {

    login=(Button)findViewById(R.id.login);
    // Store values at the time of the login attempt.
    String email = mEmailView.getText().toString();
    String password = mPasswordView.getText().toString();

    if(email.isEmpty()) {
        mEmailView.setError("E-mail is Required");
        mEmailView.requestFocus();
        return;
    }

    if(!Patterns.EMAIL_ADDRESS.matcher(email).matches()){
        mEmailView.setError("Please Enter A Valid Email");
        mEmailView.requestFocus();
        return;

    }
    if(password.isEmpty()) {
        mPasswordView.setError("Password is Required");
        mPasswordView.requestFocus();
        return;

    }
    if(password.length()        mPasswordView.setError("Password is too short(Not Less than 6)");
        mPasswordView.requestFocus();
        return;

    }
    Toast.makeText(this, "Login in Progress", Toast.LENGTH_LONG).show();
    progressBar.setVisibility(View.VISIBLE);

    mAuth.signInWithEmailAndPassword(email, password).addOnCompleteListener(this, new OnCompleteListener () {
        @Override
        public void onComplete(@NonNull Task  task) {
            if (task.isSuccessful()) {
                finish();
                progressBar.setVisibility(View.GONE);
                Intent intent=new Intent(LoginActivity.this,MainActivity.class);
                intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                startActivity(intent);
            } else {
                progressBar.setVisibility(View.GONE);
                Toast.makeText(getApplicationContext(),task.getException().getMessage(),Toast.LENGTH_LONG).show();                }
        }

    });
}


public void showerrordialog(String message){
    new AlertDialog.Builder(this)
            .setTitle("OoOps")
            .setMessage(message)
            .setPositiveButton(android.R.string.ok,null)
            .setIcon(android.R.drawable.ic_dialog_alert)
            .show();
}
public void createaccountonclick(View view){
    createaccount=(Button)findViewById(R.id.createaccount);
    Intent intent=new Intent(this,UserProfile.class);
    finish();
    startActivity(intent);
}
public void LogMeIn(View view){
    login=(Button)findViewById(R.id.login);
    attemptLogin();
}

@Override
protected void onStart() {
    super.onStart();
    if(mAuth.getCurrentUser()!=null){
        finish();
        Intent intent=new Intent(LoginActivity.this,RestoreProfileData.class);
        startActivity(intent);
    }
}

}

and this the second activity i named it facebook which will get the profile picture , name email and gender

public class Facebook extends AppCompatActivity {
TextView email;
TextView gender;
TextView facebookName;
LinearLayout infoLayout;
ProfilePictureView profilePictureView;
ImageView ima;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_facebook);
    infoLayout = (LinearLayout) findViewById(R.id.layout_info);
    profilePictureView = (ProfilePictureView) findViewById(R.id.image);
    gender = (TextView) findViewById(R.id.gender);
    ima=(ImageView)findViewById(R.id.imaging);
    facebookName = (TextView) findViewById(R.id.facebookname);
    email = (TextView) findViewById(R.id.email);
    try {
        JSONObject jsonObj = new JSONObject(getIntent().getStringExtra("object"));
        getdata(jsonObj);
    } catch (JSONException e) {
        e.printStackTrace();
    }



}

private void getdata(JSONObject object) {

    try{


        URL profile_pic =new URL("http://ift.tt/wljqS4"+object.getString("id")+"/picture?width=250&height=250");

        Picasso.with(this).load(profile_pic.toString()).into(ima);
        String fathy= object.getString("email");
        email.setText(fathy);
        facebookName.setText(object.getString("first_name"));
        gender.setText(object.getString("gender"));

    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (JSONException e) {
        e.printStackTrace();
    }
}

}

I want to get the name , gender and email of the user who logged in with facebook credentials

i am just getting the profile picture .of the user but the other data are empty with no error