java导出外部mysql

import java.io.FileWriter;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class MySQLExportCSV {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/mydatabase";
        String user = "username";
        String password = "password";
        String query = "SELECT * FROM mytable";
        String csvFile = "output.csv";

        try (Connection conn = DriverManager.getConnection(url, user, password);
             Statement stmt = conn.createStatement();
             ResultSet rs = stmt.executeQuery(query);
             FileWriter fw = new FileWriter(csvFile)) {

            int columnCount = rs.getMetaData().getColumnCount();
            while (rs.next()) {
                for (int i = 1; i <= columnCount; i++) {
                    if (i > 1) {
                        fw.append(",");
                    }
                    fw.append(rs.getString(i));
                }
                fw.append("\n");
            }
            System.out.println("Data exported to " + csvFile);
        } catch (SQLException | IOException e) {
            e.printStackTrace();
        }
    }
}