安卓:如何在应用程序中使用外部MySQL数据库

implementation 'mysql:mysql-connector-java:8.0.26'

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class MySQLConnection {
    private static final String URL = "jdbc:mysql://your_mysql_host:your_mysql_port/your_database_name";
    private static final String USERNAME = "your_mysql_username";
    private static final String PASSWORD = "your_mysql_password";

    public static Connection getConnection() throws SQLException {
        return DriverManager.getConnection(URL, USERNAME, PASSWORD);
    }
}

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class MainActivity extends AppCompatActivity {
    private Connection connection;

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

        try {
            connection = MySQLConnection.getConnection();
            Statement statement = connection.createStatement();
            String query = "SELECT * FROM your_table_name";
            ResultSet resultSet = statement.executeQuery(query);

            while (resultSet.next()) {
                // 处理查询结果
                String column1 = resultSet.getString("column1");
                String column2 = resultSet.getString("column2");
                // ...
            }

            resultSet.close();
            statement.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

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

        try {
            if (connection != null && !connection.isClosed()) {
                connection.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}