import java.io.FileOutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;

class SelToFile {

	public static void main(String[] args) throws Exception 
	{
		String url = "jdbc:firebirdsql://host[:port]/<database>";
		String username = "user";
		String password = "password";
		String filename = "result.txt";
		String sql = "select F1 from mytable";
		
		PrintWriter out = new PrintWriter(new OutputStreamWriter(new FileOutputStream(filename), "UTF-8"));
		Connection con = DriverManager.getConnection(url, username, password);
		Statement stmt = con.createStatement();
		ResultSet rs = stmt.executeQuery(sql);
		while (rs.next()) out.println(rs.getString(1));
		rs.close();
		stmt.close();
		con.close();
		out.close();
	}
}