example5_12.java

书中的例题

/* 利用哈希表(Hashtable)定义树结构 */
   import java.awt.*;
   import java.awt.event.*;
   import javax.swing.*;
   import java.util.*;
  //定义树结构类
 class TreesDemo //extends JPanel
  {
   public TreesDemo()
	{
     JFrame f = new JFrame("Hashtable定义树结构演示");
	 Hashtable hashtable1 = new Hashtable();
	 Hashtable hashtable2 = new Hashtable();
	 String[] s1={"思维论坛","Java爱好者","网上书店"};
	 String[] s2={"公司文件","私人文件","往来信件"};
	 String[] s3={"本机磁盘(C:)","本机磁盘(D:)","本机磁盘(E:)"};
     hashtable1.put("桌面",hashtable2);
     hashtable2.put("收藏夹",s1);
     hashtable2.put("我的公文包",s2);
     hashtable2.put("我的电脑",s3);
     //树进行初始化，其数据来源是root对象
     JTree tree=new JTree(hashtable1); 
     JScrollPane scroll = new JScrollPane();
	 scroll.setViewportView(tree);
	 Container con = f.getContentPane();
     con.add(scroll);
	 f.setSize(200,300);
	 f.setVisible(true);
	 f.addWindowListener(new WindowAdapter()
         {public void windowClosing(WindowEvent e)
            {System.exit(0);}
         });
	}
  }
//主类
public class Example5_12 {
 public static void main(String args[])
  { TreesDemo jf=new TreesDemo(); }
}