class AddressList extends JFrame implements TreeSelectionListener,ActionListener
{。。。。。。。
AddressList()
{。。。。。。。
   jtree=new JTree(root);
   。。。。。
   showData();
   DefaultTreeCellRenderer render=new DefaultTreeCellRenderer(); //渲染结点
   render.setLeafIcon(new ImageIcon("QQ.jpg"

);
   jtree.setCellRenderer(render);
.。。。。。。
   setResizable(false);
}
public void showData()
{ try
      {Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"

; }
   catch(ClassNotFoundException e11)
      {System.out.println("错误"+e11); }
   try
         {sqlcon=DriverManager.getConnection("jdbc

dbc:minm","",""

;
sql=sqlcon.createStatement();
rs=sql.executeQuery("select distinct * from 通讯录表"

;
         while(rs.next())
               {String n1=rs.getString(1);
               String n8=rs.getString(

;
if(n8.equals("高中同学"

)
                  {DefaultMutableTreeNode t21=new DefaultMutableTreeNode(n1);
                  t2.add(t21);
                  }
               else if(n8.equals("大学同学"

)
                  {DefaultMutableTreeNode t11=new DefaultMutableTreeNode(n1);
                  t1.add(t11);
                  }
               else if(n8.equals("初中同学"

)
                  {DefaultMutableTreeNode t31=new DefaultMutableTreeNode(n1);
                     t3.add(t31);
                  }
               else if(n8.equals("小学同学"

)
                  {DefaultMutableTreeNode t41=new DefaultMutableTreeNode(n1);
                     t4.add(t41);
                  }
               else
                  {DefaultMutableTreeNode t51=new DefaultMutableTreeNode(n1);
                     t5.add(t51);
                     }
               }
         }
   catch(SQLException e1){}
}
public void valueChanged(TreeSelectionEvent e)
{if(e.getSource()==jtree)
      {dmtn=(DefaultMutableTreeNode)jtree.getLastSelectedPathComponent();
      if(dmtn.isLeaf())
         {try
               {sqlcon=DriverManager.getConnection("jdbc

dbc:minm","",""

;
sql=sqlcon.createStatement();
rs=sql.executeQuery("select * from 通讯录表 where 姓名='"+dmtn.toString()+"'"

;
               jta.setText("");
               while(rs.next())
                  {String n1=rs.getString("姓名");
                  String n2=rs.getString("性别");
                  String n3=rs.getString("QQ");
                  String n4=rs.getString("家庭电话");
                  String n5=rs.getString("固定电话");
                  String n6=rs.getString("移动电话");
                  String n7=rs.getString("所在地址");
                  String n8=rs.getString("关系");
                  String n9=rs.getString("生日");
                  jta.append("显示从数据库中获取的数据......");
                  }
               sqlcon.close();
               }
            catch(SQLException e1){}
            }
      else
         {jscr1.setViewportView(jtree); //还是不能更新
            jta.setText("");
         }
      }
      //把jtree子结点上的图标设成两种，即男性同女性的头像用不同图标表示，但实现后程序执行变得很慢
   /*
   if(!(cellRenderered))
      {cellRenderered=true;
      jtree.setCellRenderer(new DefaultTreeCellRenderer()
            {public Component getTreeCellRendererComponent(JTree tree,Object value,
            boolean sel, boolean expanded, boolean leaf,int row, boolean hasFocus)
               {super.getTreeCellRendererComponent(tree, value, sel, expanded,leaf, row, hasFocus);
               if(leaf)
                  {ImageIcon ii= new ImageIcon("QQ.jpg");
                  setIcon(ii);
                  try
                        {Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
                        sqlcon=DriverManager.getConnection("jdbc

dbc:minm","","");
                        sql=sqlcon.createStatement();
                        rs=sql.executeQuery("select distinct * from 通讯录表 where 姓名='"+value.toString()+"'");
                        if(rs.next())
                           {if(rs.getString(2).equals("男"))
                              ii = new ImageIcon("QQ(ll).jpg");
                           else
                              ii = new ImageIcon("QQ(vvv).jpg");
                           }
                        sqlcon.close();
                        }
                     catch(ClassNotFoundException e12)
                        {System.out.println("错误"+e12); }
                     catch(SQLException e1){}
                     setIcon(ii);
                     }
               return this;
               }
            });
      } */
}
public void actionPerformed(ActionEvent e)
{if(e.getSource()==jmi11)
      {int inserting=JOptionPane.showConfirmDialog
               (null,"确定退出吗？","Warning",JOptionPane.OK_CANCEL_OPTION);
      if(inserting==JOptionPane.OK_OPTION)
            {System.exit(0);
            }
      }
。。。。
}
}