下面是一个简单的示例代码，展示了如何在Android应用中处理登录失败并使用SQLite数据库存储用户数据。

首先，在你的Android项目中添加SQLite数据库的依赖包。在build.gradle文件中添加以下代码：

dependencies {
    implementation 'androidx.sqlite:sqlite:2.2.0'
}

接下来，创建一个名为User的Java类，用于表示用户对象，并包含以下代码：

public class User {
    private int id;
    private String username;
    private String password;

    public User() { }

    public User(String username, String password) {
        this.username = username;
        this.password = password;
    }

    public int getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

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

然后，创建一个名为DatabaseHelper的Java类，用于处理SQLite数据库的创建和操作，并包含以下代码：

public class DatabaseHelper extends SQLiteOpenHelper {
    private static final String DATABASE_NAME = "users.db";
    private static final int DATABASE_VERSION = 1;
    private static final String TABLE_NAME = "users";
    private static final String COLUMN_ID = "id";
    private static final String COLUMN_USERNAME = "username";
    private static final String COLUMN_PASSWORD = "password";

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

    @Override
    public void onCreate(SQLiteDatabase db) {
        String query = "CREATE TABLE " + TABLE_NAME + "(" +
                COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
                COLUMN_USERNAME + " TEXT, " +
                COLUMN_PASSWORD + " TEXT" +
                ")";
        db.execSQL(query);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
        onCreate(db);
    }

    public void addUser(User user) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(COLUMN_USERNAME, user.getUsername());
        values.put(COLUMN_PASSWORD, user.getPassword());
        db.insert(TABLE_NAME, null, values);
        db.close();
    }

    public boolean checkUser(String username, String password) {
        String[] columns = { COLUMN_ID };
        SQLiteDatabase db = this.getReadableDatabase();
        String selection = COLUMN_USERNAME + " = ?" + " AND " + COLUMN_PASSWORD + " = ?";
        String[] selectionArgs = { username, password };
        Cursor cursor = db.query(TABLE_NAME, columns, selection, selectionArgs, null, null, null);
        int count = cursor.getCount();
        cursor.close();
        db.close();

        return count > 0;
    }
}

最后，在你的登录Activity中使用DatabaseHelper类来处理登录逻辑和保存用户数据。以下是一个简单的示例代码：

public class LoginActivity extends AppCompatActivity {
    private EditText etUsername;
    private EditText etPassword;
    private Button btnLogin;

    private DatabaseHelper databaseHelper;

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

        etUsername = findViewById(R.id.et_username);
        etPassword = findViewById(R.id.et_password);
        btnLogin = findViewById(R.id.btn_login);

        databaseHelper = new DatabaseHelper(this);

        btnLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String username = etUsername.getText().toString();
                String password = etPassword.getText().toString();
                
                if (databaseHelper.checkUser(username, password)) {
                    // 登录成功
                    Toast.makeText(LoginActivity.this, "登录成功", Toast.LENGTH_SHORT).show();
                } else {
                    // 登录失败
                    Toast.makeText(LoginActivity.this, "登录失败", Toast.LENGTH_SHORT).show();
                }
            }
        });
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        databaseHelper.close();
    }
}

这是一个简单的示例，展示了如何处理登录失败并使用SQLite数据库存储用户数据。你可以根据自己的需求对代码进行修改和完善。