У меня есть готовая регистрация , я хочу чтобы ты добавил фрагмент входа , на котором будет 2 поля ввода и кнопка : помни что войти может только уже зарегистрированный пользователь дополнительно добавь кнопку входа для фрагмента регистрации подробно выполни все предписания и дополнительно создай весь необходимы xml (если он у меня еще не создан): package com.example.myapp_2;

import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentTransaction;

import com.example.myapp_2.UI.view.activities.MainActivity;
import com.example.myapp_2.UI.view.fragments.FirstFragment;

import java.util.List;

public class RegistrationFragment extends Fragment {

private EditText editTextName, editTextEmail, editTextPassword;
private Button buttonRegister_1;

private UserDAO userDAO;

public RegistrationFragment() {

}

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

userDAO = new UserDAO(getActivity());
userDAO.open();
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {

View view = inflater.inflate(R.layout.refister, container, false);

getActivity().findViewById(R.id.bottomNavigationView).setVisibility(View.GONE);
editTextName = view.findViewById(R.id.editTextName);
editTextEmail = view.findViewById(R.id.editTextEmail);
editTextPassword = view.findViewById(R.id.editTextPassword);
buttonRegister_1 = view.findViewById(R.id.buttonRegister_1);

buttonRegister_1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String name = editTextName.getText().toString();
String email = editTextEmail.getText().toString();
String password = editTextPassword.getText().toString();

long rowID = userDAO.register(name, email, password);

if (rowID > 0) {
Toast.makeText(getActivity(), “Registration successful”, Toast.LENGTH_SHORT).show();

// вывод всех пользователей в лог
List<User> users = userDAO.getAllUsers();
Log.d(“UserDatabase”, “All users:”);
for (User user : users) {
Log.d(“UserDatabase”, user.toString());
}

getFragmentManager().popBackStack();
FragmentTransaction transaction = requireActivity().getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.nav_container, new FirstFragment());
transaction.addToBackStack(null);
transaction.commit();
} else if (rowID == -1) {
Toast.makeText(getActivity(), “Invalid email”, Toast.LENGTH_SHORT).show();

} else {
Toast.makeText(getActivity(), “Registration failed”, Toast.LENGTH_SHORT).show();
}
}
});

return view;
}

@Override
public void onDestroy() {
super.onDestroy();
userDAO.close();
}
}

package com.example.myapp_2;

public class User {
private int id;
private String name;
private String email;
private String password;

public User() {
}

public User(int id, String name, String email, String password) {
this.id = id;
this.name = name;
this.email = email;
this.password = password;
}

public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

public String getName() {
return name;
}

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

public String getEmail() {
return email;
}

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

public String getPassword() {
return password;
}

public void setPassword(String password) {
this.password = password;
}

@Override
public String toString() {
return “User {id=” + id + “, name='” + name + “‘, email=’” + email + “‘, password=’” + password + “'}”;
}
}package com.example.myapp_2;

import android.annotation.SuppressLint;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;

import java.util.ArrayList;
import java.util.List;

public class UserDAO {

private SQLiteDatabase database;
private UserDatabaseHelper dbHelper;

public UserDAO(Context context) {
dbHelper = new UserDatabaseHelper(context);
}

public void open() throws SQLException {
database = dbHelper.getWritableDatabase();
}

public void close() {
dbHelper.close();
}

public long register(String name, String email, String password) {
if (!android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches()) {
return -1; // email не соответствует формату
}

Cursor cursor = database.query(UserDatabaseHelper.TABLE_USERS,
new String[]{UserDatabaseHelper.COLUMN_EMAIL},
UserDatabaseHelper.COLUMN_EMAIL + " = ?“,
new String[]{email}, null, null, null, null);

if (cursor != null && cursor.getCount() > 0) { // если уже есть пользователь с такой почтой
cursor.close();
return -2;
}

ContentValues values = new ContentValues();
values.put(UserDatabaseHelper.COLUMN_NAME, name);
values.put(UserDatabaseHelper.COLUMN_EMAIL, email);
values.put(UserDatabaseHelper.COLUMN_PASSWORD, password);

return database.insert(UserDatabaseHelper.TABLE_USERS, null, values);
}

public boolean login(String email, String password) {
Cursor cursor = database.query(UserDatabaseHelper.TABLE_USERS,
new String[]{UserDatabaseHelper.COLUMN_EMAIL, UserDatabaseHelper.COLUMN_PASSWORD},
UserDatabaseHelper.COLUMN_EMAIL + " = ? AND " + UserDatabaseHelper.COLUMN_PASSWORD + " = ?”,
new String[]{email, password}, null, null, null, null);

if (cursor != null && cursor.getCount() > 0) {
cursor.close();
return true;
} else {
return false;
}
}

@SuppressLint(“Range”)
public List<User> getAllUsers() {
List<User> users = new ArrayList<>();

Cursor cursor = database.query(UserDatabaseHelper.TABLE_USERS,
new String[]{UserDatabaseHelper.COLUMN_ID, UserDatabaseHelper.COLUMN_NAME,
UserDatabaseHelper.COLUMN_EMAIL, UserDatabaseHelper.COLUMN_PASSWORD},
null, null, null, null, null);

if (cursor != null && cursor.moveToFirst()) {
do {
User user = new User();
user.setId(cursor.getInt(cursor.getColumnIndex(UserDatabaseHelper.COLUMN_ID)));
user.setName(cursor.getString(cursor.getColumnIndex(UserDatabaseHelper.COLUMN_NAME)));
user.setEmail(cursor.getString(cursor.getColumnIndex(UserDatabaseHelper.COLUMN_EMAIL)));
user.setPassword(cursor.getString(cursor.getColumnIndex(UserDatabaseHelper.COLUMN_PASSWORD)));

users.add(user);
} while (cursor.moveToNext());

cursor.close();
}

return users;
}
}
package com.example.myapp_2;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class UserDatabaseHelper extends SQLiteOpenHelper {

private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = “UserDatabase”;

public static final String TABLE_USERS = “users”;
public static final String COLUMN_ID = “_id”;
public static final String COLUMN_NAME = “name”;
public static final String COLUMN_EMAIL = “email”;
public static final String COLUMN_PASSWORD = “password”;

public UserDatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_USERS_TABLE = “CREATE TABLE " + TABLE_USERS + “(”
+ COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT,”
+ COLUMN_NAME + " TEXT,“
+ COLUMN_EMAIL + " TEXT,”
+ COLUMN_PASSWORD + " TEXT"
+ “)”;
db.execSQL(CREATE_USERS_TABLE);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_USERS);
onCreate(db);
}
}
Добавленный фрагмент входа будет выглядеть следующим образом:

public class LoginFragment extends Fragment {

private EditText editTextEmail, editTextPassword;
private Button buttonLogin;

private UserDAO userDAO;

public LoginFragment() {

}

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

userDAO = new UserDAO(getActivity());
userDAO.open();
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {

View view = inflater.inflate(R.layout.login, container, false);

getActivity().findViewById(R.id.bottomNavigationView).setVisibility(View.GONE);
editTextEmail = view.findViewById(R.id.editTextEmail);
editTextPassword = view.findViewById(R.id.editTextPassword);
buttonLogin = view.findViewById(R.id.buttonLogin);

buttonLogin.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String email = editTextEmail.getText().toString();
String password = editTextPassword.getText().toString();

if (userDAO.login(email, password)) {
Toast.makeText(getActivity(), “Login successful”, Toast.LENGTH_SHORT).show();

// переход на другой фрагмент
FragmentTransaction transaction = requireActivity().getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.nav_container, new FirstFragment());
transaction.addToBackStack(null);
transaction.commit();
} else {
Toast.makeText(getActivity(), “Invalid email or password”, Toast.LENGTH_SHORT).