在JTree中添加一个结点

Question

我想在JTree中添加一个结点，结点名由用户输入，就是由菜单中选择添加结点，然后调用一个输入名称的程序，根据输入的名称，在树中添加一个这个名的结点，现在做了很长时间，就是做不好，谁来帮帮我，给分。我现在的问题是如何得到输入的名称的问题。
newTable.addActionListener(new ActionListener()
    {
      public void actionPerformed(ActionEvent e)
      {
        AddTable nt = new AddTable();
        if(nt.getFlag())
        {
          System.out.println(nt.getFlag());
          String tableName = nt.getTableName();
          addNode(tableName);
        }
      }
    });
上面是菜单的事件
package datatrim;import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import com.borland.jbcl.layout.*;    
public class AddTable
{
  boolean valueB = false;
  String tableName;
  JFrame jf;
  JTextField tableput;
  public AddTable()
  {
    jf = new JFrame("建表");
    Container contentPane = jf.getContentPane();
    contentPane.setLayout(new XYLayout());
    
    JLabel table = new JLabel("请输入表名");
    tableput = new JTextField();
    JButton ok = new JButton("确定");
    JButton no = new JButton("取消");
    contentPane.add(table,new XYConstraints(10,10,80,20));
    contentPane.add(tableput,new XYConstraints(90,10,100,20));
    contentPane.add(ok,new XYConstraints(30,50,60,20));
    contentPane.add(no,new XYConstraints(100,50,60,20));
    tableput.addKeyListener(new KeyAdapter()
    {
      public void keyPressed(KeyEvent ke)
      {
        if(ke.getKeyCode()==KeyEvent.VK_ENTER)
        {
          ok_actionPerformed();
        }
      }
    });
    ok.addActionListener(new ActionListener()
    {
      public void actionPerformed(ActionEvent e)
      {
        ok_actionPerformed();
      }
    });
    no.addActionListener(new ActionListener()
    {
      public void actionPerformed(ActionEvent e)
      {
        jf.dispose();
      }
    });
    
    jf.setSize(200,120);
    jf.setVisible(true);
    jf.setResizable(false);
  }
  public void ok_actionPerformed()
  {
    String tableName1 = tableput.getText();
    if(tableName1.length()!=6)
    {
      JOptionPane.showMessageDialog(jf,"表名的格式为＜年＋月＞！","输入失败！",0);
    }
    else 
    {
        int year = Integer.parseInt(tableName1.substring(0,4));
        int month = Integer.parseInt(tableName1.substring(4,tableName1.length()));
        System.out.println(year+"\n"+month);
        if((year<1900)||(year>2500)||(month<1)||(month>12))
        {
          JOptionPane.showMessageDialog(jf,"表名的格式为＜年＋月＞！","输入失败！",0);
        }
        else
        {
            valueB = true;
            tableName = tableName1;
            //建表程序String sql = ""
            jf.dispose();
         }
    }
  }
  
  protected void processWindowEvent(WindowEvent e)
  {
    if (e.getID() == WindowEvent.WINDOW_CLOSING)
    {
      jf.dispose();
    }
  }
  public String getTableName()
  {
    return tableName;
  }
  public boolean getFlag()
  {
    return valueB;
  }
  /*public static void main(String args[])
  {
    AddTable at = new AddTable();
  }*/
}
上面是输入名称的页面