cara berkomunikasi antar kelas

package javaapplication2;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
class baru
{
    public baru(FuTest fdf){

    }
}
class FuTest {
  Main ma = null;
  private Object[][] cellData =
                        {
                            { "1-1", "1-2", "1-3" },
                            { "2-1", "2-2", "2-3" }
                        };
  private String[] columnNames = { "col1", "col2","col3" };
  public FuTest(Main ma){
    this.ma = ma ;
  }
  //! panggil ini
  public Object [][] fuGetCellData(){
    return this.cellData;
  }
  //! panggil ini
  public String [] fuGetColumnNames(){
    return this.columnNames;
  }
}
public class Main extends JFrame{
    public Main(){
        FuTest test = new FuTest(this);
        baru d= new baru(test);
        test.fuGetCellData();
        test.fuGetColumnNames();
        JTable table = new JTable(test.fuGetCellData(),test.fuGetColumnNames());
        JScrollPane wadah = new JScrollPane(table);
        setSize(300,300);
        add(wadah);
        setVisible(true);
    }
  public static void main(String[] argv) throws Exception {
      new Main();
  }
}