Java核心技术II-第6章-简单树-源代码

package javaee.vii.ch06;

import java.awt.EventQueue;
import javax.swing.JFrame;

/**
 * This program shows a simple tree.
 * @author lcwell
 */
public class SimpleTree {
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable(){

            @Override
            public void run() {
                JFrame frame = new SimpleTreeFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setVisible(true);
            }
        });
    }
}

package javaee.vii.ch06;

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;

/**
 * This frame contains a simple tree that displays a munually constructed tree model.
 * @author lcwell
 */
public class SimpleTreeFrame extends JFrame {
    
    public SimpleTreeFrame() {
        setTitle("SimpleTree");
        setSize(DEFAULT_WIDTH, DEFUALT_HEIGHT);
        
        // set up tree model data
        DefaultMutableTreeNode root = new DefaultMutableTreeNode("世界");
        DefaultMutableTreeNode country = new DefaultMutableTreeNode("中国");
        root.add(country);
        DefaultMutableTreeNode state = new DefaultMutableTreeNode("广东省");
        country.add(state);
        state.add(new DefaultMutableTreeNode("珠海市"));
        state.add(new DefaultMutableTreeNode("广州市"));
        state = new DefaultMutableTreeNode("湖南省");
        country.add(state);
        state.add(new DefaultMutableTreeNode("益阳市"));
        country = new DefaultMutableTreeNode("美国");
        root.add(country);
        state = new DefaultMutableTreeNode("加利福尼亚州");
        country.add(state);
        state.add(new DefaultMutableTreeNode("纽约"));
        
        // contruct tree and put it in a scroll pane
        JTree tree = new JTree(root);
        add(new JScrollPane(tree));
    }
    
    private static final int DEFAULT_WIDTH = 300;
    private static final int DEFUALT_HEIGHT = 200;
}

运行效果：