Como gravar um banco de dados em um arquivo txt

import java.sql.*;

public class Teste
{

    public static void main(String args[]) 
    {
    	String url = "jdbc:odbc:java";
  
      	try
    	{
    	Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
    	Connection conn = DriverManager.getConnection(url);
        System.out.println("Conexão efetuada com sucesso, aguarde !!!");
        
        Statement stmt = con.createStatement();
	ResultSet rs = stmt.executeQuery("select * from nomedatabela");
                FileWriter writer = new FileWriter("saida.txt");
                PrintWriter out = new PrintWriter(writer);
	while(rs.next()) 
	{
 	 	String codigo1 = rs.getString("coluna1");
 	 	String codigo2 = rs.getString("coluna2");
 	 	out.println(codigo1 + "," + codigo2);
	}
	rs.close();
	stmt.close();
	conn.close();
                out.close();
                writer.close();
        }
    	catch (ClassNotFoundException cnfex)
    	{
      	System.err.println("Falha na leitura do driver JDBC/ODBC");
      	System.exit(1);
    	}
    	catch (IOException ioex)
    	{
      	System.err.println("Erro de IO");
      	System.exit(1);
    	}
    	catch (SQLException sqlex)
    	{
    	System.err.println("Falha no SQL");
      	System.exit(1);
	}

    }

}