treenodedemo.java

电子工业出版社出版的《java2应用开发指南》配套光盘源代码

//TreeNodeDemo.java
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;

public class TreeNodeDemo extends JFrame 
{
	protected JTree  m_tree ;
	protected JTextField m_display;

	public TreeNodeDemo()
	{
		super("SNMP Tree [OID]");
		
		//创建5个树的用户对象引用
        //Object[] nodes = new Object[5];
		
		//创建树的根节点（第一层节点）
		DefaultMutableTreeNode top = new DefaultMutableTreeNode(
			new OidNode(1, "ISO"));
		DefaultMutableTreeNode parent = top;

		//创建树根节点的子节点（第二层节点）
		DefaultMutableTreeNode node = new DefaultMutableTreeNode(new OidNode(0, "standard"));
		parent.add(node);
		node = new DefaultMutableTreeNode(new OidNode(2,"member-body"));
		parent.add(node);
		node = new DefaultMutableTreeNode(new OidNode(3, "org"));
		parent.add(node);
		parent = node;

		//创建第二层节点的子节点（第三层节点）
		node = new DefaultMutableTreeNode(new OidNode(6, "dod"));
		parent.add(node);
		parent = node;
		//创建第三层节点的子节点（第四层节点）
		node = new DefaultMutableTreeNode(new OidNode(1,"internet"));
		parent.add(node);
		parent = node;
		//创建第四层节点的子节点（第五层节点）
		node = new DefaultMutableTreeNode(new OidNode(1,"directory"));
		parent.add(node);
		node = new DefaultMutableTreeNode(new OidNode(2,"mgmt"));
		parent.add(node);
		node.add(new DefaultMutableTreeNode(new OidNode(1, "mib-2")));
		node = new DefaultMutableTreeNode(new OidNode(3,"experimental"));
		parent.add(node);
		node = new DefaultMutableTreeNode(new OidNode(4,"private"));
		node.add(new DefaultMutableTreeNode(new OidNode(1,"enterprises")));
		parent.add(node);
		node = new DefaultMutableTreeNode(new OidNode(5,"security"));
		parent.add(node);
		node = new DefaultMutableTreeNode(new OidNode(6,"snmpV2"));
		parent.add(node);
		node = new DefaultMutableTreeNode(new OidNode(7,"mail"));
		parent.add(node);
		
		//以树的根节点构造整个树
		m_tree = new JTree(top);
		/*
		m_tree =new JTree(top)
		{
		//setting tree tooltip text
	        public String getToolTipText(MouseEvent e)
			{	
				//获取鼠标在树组件中选择位置的树的路径
				TreePath path = m_tree.getPathForLocation(e.getX(),e.getY());
				//如果鼠标没有选择树节点上，则直接返回
				if( path == null ) return null;
				//获取当前树路径的存储的树节点对象的数组（从根节点到当前树节点）
				Object[] nodes = path.getPath();
				String oid = "";
				for (int k=0; k<nodes.length; k++)	{
					//强制转化成树节点
				DefaultMutableTreeNode treenode = (DefaultMutableTreeNode)nodes[k];
					//从树节点中获取其用户对象（OidNode的实例）
					OidNode nd = (OidNode)treenode.getUserObject();
					//把用户对象的对象标识进行累积
				oid += "."+nd.getId();
				}
				return oid;
			}
		};
		ToolTipManager.sharedInstance().registerComponent(m_tree);
		*/
		
		
		//display root handle of tree
		m_tree.setShowsRootHandles(true); 
		//Setting root line for Tree
		m_tree.putClientProperty("JTree.lineStyle", "Angled");
		//设置树的树节点是不可编辑的
		m_tree.setEditable(false);
		//添加监视树的鼠标事件
		m_tree.addMouseListener(new MouseAdapter(){
            public void mouseClicked(MouseEvent e){
                tvwTreeView_mouseClicked(e);
            }
        });
        
		//把树组件加入到滚动面板中
		JScrollPane s = new JScrollPane(m_tree);
		getContentPane().add(s, BorderLayout.CENTER);

		m_display = new JTextField();
		m_display.setEditable(false);
		getContentPane().add(m_display, BorderLayout.SOUTH);
		//显示框架窗口
		setSize(400, 300);
		setVisible(true);
	}

	public static void main(String argv[]) 
	{
		TreeNodeDemo frame=new TreeNodeDemo();
		
		frame.addWindowListener(new WindowAdapter(){
			public void windowClosing(WindowEvent e) 
			{
				System.exit(0);
			}
		});
	}
	//处理树组件的鼠标单击事件
	private void tvwTreeView_mouseClicked(MouseEvent e)
	{
		//获取鼠标在树组件中选择位置的树的路径
		TreePath path = m_tree.getPathForLocation(e.getX(),e.getY());
		//如果鼠标没有选择树节点上，则直接返回
		if( path == null ) return;
		//获取当前树路径的存储的树节点对象的数组（从根节点到当前树节点）
		Object[] nodes = path.getPath();
			String oid = "";
			for (int k=0; k<nodes.length; k++)
			{
				//强制转化成树节点
				DefaultMutableTreeNode node = (DefaultMutableTreeNode)nodes[k];
				//从树节点中获取其用户对象（OidNode的实例）
				OidNode nd = (OidNode)node.getUserObject();
				//把用户对象的对象名称进行累积
				oid += "."+nd.getName();
			}
			m_display.setText(oid);
	}
}
//树的用户对象类（UserObject)，用于封装SNMP的OID
class OidNode
{
	//对象标识
	private int    m_id;
	//对象名称
	private String m_name;
	//构造方法
	public OidNode(int id, String name)
	{
		m_id = id;
		m_name = name;
	}
	//获取对象标识
	public int getId() 
	{ 
		return m_id;
	}
	//得到对象名称
	public String getName() 
	{ 
		return m_name;
	}
	//用户对象的字符串化，这个方法重写了Object.toString()
	public String toString() 
	{ 
		return m_name;
	}
}