问答题

本题中定义了一个树型的通信录,窗El左侧是一个树,
右侧是一个文本域,单击树的结点,则在右侧文本域中显示
相关信息,如果单击的是树结点,则显示对应名字的电话
信息。
import javax.swing.*;
import javax.swing.tree.*; import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;
class Mytree2 extends JFrame 
{JTree tree=null;JTextArea text=new JTextArea
(20,20);
Mytree2()
{Container con=getContentPane();
DefauhMutableTreeNode root=new Default-
MutableTreeNode("同学通信录");
DefaultMutableTreeNode tl=new Default-
MutableTreeNode("大学同学");
DefaultMutableTreeNode t2=new Default-
MutableTreeNode("研究生同学");
DefaultMutableTreeNode tl l=new Default-
MutatleTreeNode("陈艳");
DefaultMutableTreeNode tl 2=new Default-
MutableTreeNode("李小永");
DefaultMutableTreeNode t2 1=new Defauh-
MutableTreeNode("王小小");
DefauhMutableTreeNode t2 2=new Defauh-
MutableTreeNode("董小");
setTitle("java2");
root.add(t1);root.add(t2);
tl.add(t1_1);tl.add(t1_2);t2.add(t2_1);t2.
add(t2_2);
tree=new JTree(root); JSerollPane scrollpane=new JScrollPane(text);
JSplitPane splitpane=new JSplitPane(JSplitPane.
HORIZONTAL SPLIT,
true,tree,scrollpane);
tree.addTreeSeleetionListener(this); con.add(splitpane);
addWindowListener(new WindowAdapter()
{ public void windowClosing(WindowEvent e)
{System.exit(0);}});
setVisible(true);setBounds(70,80,200,300);
}
public void valueChanged(TreeSelectionEvent e)
{if(e.getSouree()= =tree)
{DefauhMutableTreeNode node=
(DefaultMutableTreeNode)tree.getLastSelected-
PathComponent();
if(node.isLeaf())
(String str=  ;
if(str.equals("陈艳"))
(text.setText(str+":联系电话:0411-
4209876");}
else if(str.equals("李小永")) {text.setText(str+":联系电话:010-
62789876");} else if(str.equals("王小小"))
{text.setText(str+":联系电话:0430-
63596677");)
else if(str.equals("董小"))
{text.setText(str+":联系电话:020-
85192789");}
}
else
{text.setText(node.getUserObject().toString
());
}
}
}
} public class java2
{public static void main(String args[])
{Mytree2 win=new Mytree2();win.pack();}
}

【参考答案】

第1处:implements TreeSelectionListener
第2处:node.toString(......

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