Tree Example3

import java.awt.*;import java.awt.event.*;import java.util.*;import javax.swing.*;import javax.swing.tree.*;public class ExampleFrame_03 extends JFrame {private DefaultMutableTreeNode root;public static void main(String args[]) {ExampleFrame_03 frame = new ExampleFrame_03();frame.setVisible(true);}public ExampleFrame_03() {super();setTitle("遍历树节点");setBounds(100, 100, 290, 260);setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);root = new DefaultMutableTreeNode("ROOT");DefaultMutableTreeNode nodeFirstA = new DefaultMutableTreeNode("FirstA");nodeFirstA.add(new DefaultMutableTreeNode("SecondAA"));nodeFirstA.add(new DefaultMutableTreeNode("SecondAB"));root.add(nodeFirstA);DefaultMutableTreeNode nodeFirstB = new DefaultMutableTreeNode("FirstB");root.add(nodeFirstB);DefaultMutableTreeNode nodeFirstC = new DefaultMutableTreeNode("FirstC");nodeFirstC.add(new DefaultMutableTreeNode("SecondCA"));DefaultMutableTreeNode nedeSecondCB = new DefaultMutableTreeNode("SecondCB");nedeSecondCB.add(new DefaultMutableTreeNode("SecondCBA"));nedeSecondCB.add(new DefaultMutableTreeNode("SecondCBB"));nodeFirstC.add(nedeSecondCB);nodeFirstC.add(new DefaultMutableTreeNode("SecondCC"));root.add(nodeFirstC);JTree tree = new JTree(root);getContentPane().add(tree, BorderLayout.CENTER);final JPanel panel = new JPanel();panel.setLayout(new GridLayout(0, 1));getContentPane().add(panel, BorderLayout.EAST);final JButton button = new JButton("按前序遍历节点");button.addActionListener(new ButtonActionListener("按前序遍历"));panel.add(button);final JButton button_1 = new JButton("按后序遍历节点");button_1.addActionListener(new ButtonActionListener("按后序遍历"));panel.add(button_1);final JButton button_2 = new JButton("以广度优先遍历");button_2.addActionListener(new ButtonActionListener("以广度优先遍历"));panel.add(button_2);final JButton button_3 = new JButton("以深度优先遍历");button_3.addActionListener(new ButtonActionListener("以深度优先遍历"));panel.add(button_3);final JButton button_4 = new JButton("遍历直属子节点");button_4.addActionListener(new ButtonActionListener("遍历子节点"));panel.add(button_4);}private class ButtonActionListener implements ActionListener {private String mode;public ButtonActionListener(String mode) {this.mode = mode;}public void actionPerformed(ActionEvent e) {Enumeration enumeration;// 声明节点枚举对象if (mode.equals("按前序遍历"))// 按前序遍历所有树节点enumeration = root.preorderEnumeration();else if (mode.equals("按后序遍历"))// 按后序遍历所有树节点enumeration = root.postorderEnumeration();else if (mode.equals("以广度优先遍历"))// 以广度优先遍历所有树节点enumeration = root.breadthFirstEnumeration();else if (mode.equals("以深度优先遍历"))// 以深度优先遍历所有树节点enumeration = root.depthFirstEnumeration();elseenumeration = root.children(); // 遍历该节点的子节点while (enumeration.hasMoreElements()) {// 遍历节点枚举对象DefaultMutableTreeNode node;// 获得节点node = (DefaultMutableTreeNode) enumeration.nextElement();// 根据节点级别输出占位符for (int l = 0; l < node.getLevel(); l++) {System.out.print("----");}System.out.println(node.getUserObject());// 输出节点标签}System.out.println();System.out.println();}}}