JTree

package swing.tree;

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.lang.reflect.Field;
import java.util.Enumeration;

import javax.lang.model.element.Modifier;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.JTree;
import javax.swing.SwingUtilities;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreeNode;
import javax.swing.tree.TreePath;
import javax.swing.tree.TreeSelectionModel;

/*2015-7-11*/
public class ClassTree {
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

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

    }

}

class ClassTreeFrame extends JFrame {
    private static final long serialVersionUID = 3866055150465649395L;

    private DefaultMutableTreeNode root;
    private DefaultTreeModel model;
    private JTree tree;
    private JTextField textField;
    private JTextArea textArea;
    private static final int DEFAULT_WIDTH = 800;
    private static final int DEFAULT_HEIGHT = 600;

    public ClassTreeFrame() {
        setTitle(getClass().getSimpleName());
        setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
        root = new DefaultMutableTreeNode(java.lang.Object.class);
        model = new DefaultTreeModel(root);
        tree = new JTree(model);

        addClass(getClass());

        ClassNameTreeCellRender render = new ClassNameTreeCellRender();
        String filename = getClass().getResource("/swing/tree/red-ball.gif").getPath();
        render.setClosedIcon(new ImageIcon(filename));
        filename = getClass().getResource("/swing/tree/yellow-ball.gif").getPath();
        render.setOpenIcon(new ImageIcon(filename));
        filename = getClass().getResource("/swing/tree/blue-ball.gif").getPath();
        render.setLeafIcon(new ImageIcon(filename));
        tree.setCellRenderer(render);

        tree.addTreeSelectionListener(new TreeSelectionListener() {

            @Override
            public void valueChanged(TreeSelectionEvent e) {

                TreePath path = tree.getSelectionPath();
                if (path == null) {
                    return;
                }
                DefaultMutableTreeNode selectedNode = (DefaultMutableTreeNode) path.getLastPathComponent();
                Class<?> c = (Class<?>) selectedNode.getUserObject();
                String description = getFileDescription(c);
                textArea.setText(description);
            }
        });

        int mode = TreeSelectionModel.SINGLE_TREE_SELECTION;
        tree.getSelectionModel().setSelectionMode(mode);

        textArea = new JTextArea();

        JPanel panel = new JPanel();
        panel.setLayout(new GridLayout(1, 2));
        panel.add(new JScrollPane(tree));
        panel.add(new JScrollPane(textArea));

        add(panel, BorderLayout.CENTER);

        addTextField();

    }

    private void addTextField() {
        JPanel panel = new JPanel();
        ActionListener addListener = new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    String text = textField.getText();
                    addClass(Class.forName(text));
                    textField.setText("");
                } catch (ClassNotFoundException e1) {
                    JOptionPane.showMessageDialog(ClassTreeFrame.this, e1.getMessage());
                }
            }
        };

        textField = new JTextField(20);
        textField.addActionListener(addListener);
        panel.add(textField);

        JButton addButton = new JButton("Add");
        addButton.addActionListener(addListener);
        panel.add(addButton);
        add(panel, BorderLayout.SOUTH);

    }

    protected String getFileDescription(Class<?> c) {
        StringBuilder r = new StringBuilder();
        Field[] fields = c.getDeclaredFields();
        for (Field field : fields) {
            if (field.getModifiers() == Modifier.STATIC.ordinal()) {
                r.append("static");
            }
            r.append(field.getType().getName())
                    .append("")
                    .append(field.getName())
                    .append("\n");

        }

        return r.toString();
    }

    private DefaultMutableTreeNode addClass(Class<?> c) {
        if (c.isInterface() || c.isPrimitive()) {
            return null;
        }

        DefaultMutableTreeNode node = findUserObject(c);
        if (node != null) {
            return node;
        }

        Class<?> s = c.getSuperclass();
        DefaultMutableTreeNode parent;
        if (s == null) {
            parent = root;
        } else {
            parent = addClass(s);
        }

        DefaultMutableTreeNode newChild = new DefaultMutableTreeNode(c);
        model.insertNodeInto(newChild, parent, parent.getChildCount());

        TreePath path = new TreePath(model.getPathToRoot(newChild));
        tree.makeVisible(path);
        return newChild;
    }

    private DefaultMutableTreeNode findUserObject(Object obj) {
        @SuppressWarnings("unchecked")
        Enumeration<TreeNode> e = root.breadthFirstEnumeration();
        while (e.hasMoreElements()) {
            DefaultMutableTreeNode node = (DefaultMutableTreeNode) e.nextElement();
            if (node.getUserObject().equals(obj)) {
                return node;
            }
        }
        return null;
    }

}

class ClassNameTreeCellRender extends DefaultTreeCellRenderer {
    private static final long serialVersionUID = -2145290206168596413L;
    private Font plainFont;
    private Font italicFont;

    @Override
    public Component getTreeCellRendererComponent(JTree tree, Object value, boolean sel,
            boolean expanded, boolean leaf, int row, boolean hasFocus) {

        Component comp = super.getTreeCellRendererComponent(tree, value, sel, expanded, leaf, row, hasFocus);

        DefaultMutableTreeNode node = (DefaultMutableTreeNode) value;
        Class<?> c = (Class<?>) node.getUserObject();

        if (plainFont == null) {
            plainFont = getFont();
            if (plainFont == null) {
                italicFont = plainFont.deriveFont(Font.ITALIC);
            }
        }

        if (c.getModifiers() == Modifier.ABSTRACT.ordinal()) {
            setFont(plainFont);
        } else {
            comp.setFont(italicFont);
        }

        return comp;
    }

}