接到老师的题目,我需要用javaswing做一棵学校的组织机构树,从校长,到下面的系主任,再到各个办公室......节点下面可能是另外的节点,也可能包含最终的叶子(人)。这个暑期作业对我这个菜鸟来说好郁闷啊~~~~求高手们给我点解题思路吧!!最好有那么两段代码。。谢谢

解决方案 »

  1.   

    JTree刚开始显示的只有根节点
      

  2.   

    /**
     * A 1.4 application that requires the following additional files:
     *   TreeDemoHelp.html
     *    arnold.html
     *    bloch.html
     *    chan.html
     *    jls.html
     *    swingtutorial.html
     *    tutorial.html
     *    tutorialcont.html
     *    vm.html
     */
    import javax.swing.JEditorPane;
    import javax.swing.JFrame;
    import javax.swing.JPanel;
    import javax.swing.JScrollPane;
    import javax.swing.JSplitPane;
    import javax.swing.UIManager;import javax.swing.JTree;
    import javax.swing.tree.DefaultMutableTreeNode;
    import javax.swing.tree.TreeSelectionModel;
    import javax.swing.event.TreeSelectionEvent;
    import javax.swing.event.TreeSelectionListener;import java.net.URL;
    import java.io.IOException;
    import java.awt.Dimension;
    import java.awt.GridLayout;public class TreeDemo extends JPanel
                          implements TreeSelectionListener {
        private JEditorPane htmlPane;
        private JTree tree;
        private URL helpURL;
        private static boolean DEBUG = false;    //Optionally play with line styles.  Possible values are
        //"Angled" (the default), "Horizontal", and "None".
        private static boolean playWithLineStyle = false;
        private static String lineStyle = "Horizontal";
        
        //Optionally set the look and feel.
        private static boolean useSystemLookAndFeel = false;    public TreeDemo() {
            super(new GridLayout(1,0));        //Create the nodes.
            DefaultMutableTreeNode top =
                new DefaultMutableTreeNode("The Java Series");
            createNodes(top);        //Create a tree that allows one selection at a time.
            tree = new JTree(top);
            tree.getSelectionModel().setSelectionMode
                    (TreeSelectionModel.SINGLE_TREE_SELECTION);        //Listen for when the selection changes.
            tree.addTreeSelectionListener(this);        if (playWithLineStyle) {
                System.out.println("line style = " + lineStyle);
                tree.putClientProperty("JTree.lineStyle", lineStyle);
            }        //Create the scroll pane and add the tree to it. 
            JScrollPane treeView = new JScrollPane(tree);        //Create the HTML viewing pane.
            htmlPane = new JEditorPane();
            htmlPane.setEditable(false);
            initHelp();
            JScrollPane htmlView = new JScrollPane(htmlPane);        //Add the scroll panes to a split pane.
            JSplitPane splitPane = new JSplitPane(JSplitPane.VERTICAL_SPLIT);
            splitPane.setTopComponent(treeView);
            splitPane.setBottomComponent(htmlView);        Dimension minimumSize = new Dimension(100, 50);
            htmlView.setMinimumSize(minimumSize);
            treeView.setMinimumSize(minimumSize);
            splitPane.setDividerLocation(100); //XXX: ignored in some releases
                                               //of Swing. bug 4101306
            //workaround for bug 4101306:
            //treeView.setPreferredSize(new Dimension(100, 100));         splitPane.setPreferredSize(new Dimension(500, 300));        //Add the split pane to this panel.
            add(splitPane);
        }    /** Required by TreeSelectionListener interface. */
        public void valueChanged(TreeSelectionEvent e) {
            DefaultMutableTreeNode node = (DefaultMutableTreeNode)
                               tree.getLastSelectedPathComponent();        if (node == null) return;        Object nodeInfo = node.getUserObject();
            if (node.isLeaf()) {
                BookInfo book = (BookInfo)nodeInfo;
                displayURL(book.bookURL);
                if (DEBUG) {
                    System.out.print(book.bookURL + ":  \n    ");
                }
            } else {
                displayURL(helpURL); 
            }
            if (DEBUG) {
                System.out.println(nodeInfo.toString());
            }
        }    private class BookInfo {
            public String bookName;
            public URL bookURL;        public BookInfo(String book, String filename) {
                bookName = book;
                bookURL = TreeDemo.class.getResource(filename);
                if (bookURL == null) {
                    System.err.println("Couldn't find file: "
                                       + filename);
                }
            }        public String toString() {
                return bookName;
            }
        }    private void initHelp() {
            String s = "TreeDemoHelp.html";
            helpURL = TreeDemo.class.getResource(s);
            if (helpURL == null) {
                System.err.println("Couldn't open help file: " + s);
            } else if (DEBUG) {
                System.out.println("Help URL is " + helpURL);
            }        displayURL(helpURL);
        }
      

  3.   

    private void displayURL(URL url) {
            try {
                if (url != null) {
                    htmlPane.setPage(url);
                } else { //null url
    htmlPane.setText("File Not Found");
                    if (DEBUG) {
                        System.out.println("Attempted to display a null URL.");
                    }
                }
            } catch (IOException e) {
                System.err.println("Attempted to read a bad URL: " + url);
            }
        }    private void createNodes(DefaultMutableTreeNode top) {
            DefaultMutableTreeNode category = null;
            DefaultMutableTreeNode book = null;        category = new DefaultMutableTreeNode("Books for Java Programmers");
            top.add(category);        //original Tutorial
            book = new DefaultMutableTreeNode(new BookInfo
                ("The Java Tutorial: A Short Course on the Basics",
                "tutorial.html"));
            category.add(book);        //Tutorial Continued
            book = new DefaultMutableTreeNode(new BookInfo
                ("The Java Tutorial Continued: The Rest of the JDK",
                "tutorialcont.html"));
            category.add(book);        //JFC Swing Tutorial
            book = new DefaultMutableTreeNode(new BookInfo
                ("The JFC Swing Tutorial: A Guide to Constructing GUIs",
                "swingtutorial.html"));
            category.add(book);        //Bloch
            book = new DefaultMutableTreeNode(new BookInfo
                ("Effective Java Programming Language Guide",
         "bloch.html"));
            category.add(book);        //Arnold/Gosling
            book = new DefaultMutableTreeNode(new BookInfo
                ("The Java Programming Language", "arnold.html"));
            category.add(book);        //Chan
            book = new DefaultMutableTreeNode(new BookInfo
                ("The Java Developers Almanac",
                 "chan.html"));
            category.add(book);        category = new DefaultMutableTreeNode("Books for Java Implementers");
            top.add(category);        //VM
            book = new DefaultMutableTreeNode(new BookInfo
                ("The Java Virtual Machine Specification",
                 "vm.html"));
            category.add(book);        //Language Spec
            book = new DefaultMutableTreeNode(new BookInfo
                ("The Java Language Specification",
                 "jls.html"));
            category.add(book);
        }
            
        /**
         * Create the GUI and show it.  For thread safety,
         * this method should be invoked from the
         * event-dispatching thread.
         */
        private static void createAndShowGUI() {
            if (useSystemLookAndFeel) {
                try {
                    UIManager.setLookAndFeel(
                        UIManager.getSystemLookAndFeelClassName());
                } catch (Exception e) {
                    System.err.println("Couldn't use system look and feel.");
                }
            }        //Make sure we have nice window decorations.
            JFrame.setDefaultLookAndFeelDecorated(true);        //Create and set up the window.
            JFrame frame = new JFrame("TreeDemo");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        //Create and set up the content pane.
            TreeDemo newContentPane = new TreeDemo();
            newContentPane.setOpaque(true); //content panes must be opaque
            frame.setContentPane(newContentPane);        //Display the window.
            frame.pack();
            frame.setVisible(true);
        }    public static void main(String[] args) {
            //Schedule a job for the event-dispatching thread:
            //creating and showing this application's GUI.
            javax.swing.SwingUtilities.invokeLater(new Runnable() {
                public void run() {
                    createAndShowGUI();
                }
            });
        }
    }