JTree 常用方法

package com.swing.demo;

import java.awt.Component;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.SwingUtilities;
import javax.swing.event.TreeExpansionEvent;
import javax.swing.event.TreeExpansionListener;
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;

import com.swing.model.User;

/**
 * JTree 常用方法.
 * @author Administrator
 *
 */
public class TreeDemo {
    public static void main(String[] args) {
        final JTree tree = createTree();
        // 窗体设置
        JFrame frame = new JFrame("JTreeDemo");
        // 构造完树之后还要把树放在JScollPanel上,否则树显示会有问题
        JScrollPane treeView = new JScrollPane(tree);
        frame.add(treeView);
        frame.setSize(300, 300);
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        // 添加树节点选择事件
        tree.addTreeSelectionListener(new TreeSelectionListener() {

            @Override
            public void valueChanged(TreeSelectionEvent e) {
                // 取得TreePath
                // TreePath newPath = event.getNewLeadSelectionPath();
                // TreePath oldPath = event.getOldLeadSelectionPath();
                // 通过JTree取得Node
                // JTree tree = (JTree) event.getSource();
                // tree.getLastSelectedPathComponent();
                DefaultMutableTreeNode node = (DefaultMutableTreeNode) tree
                        .getLastSelectedPathComponent();
                if (node == null) {
                    return;
                }

                Object object = node.getUserObject();
                if (node.isLeaf()) {
                    User user = (User) object;
                    System.out.println("你选择了：" + user.toString());
                }

                // 取得根节点:
                TreeNode rootNode = (TreeNode) tree.getModel().getRoot();
                // 取得树的数据模型:
                DefaultTreeModel treeModel = (DefaultTreeModel) tree.getModel();
                // 取得树的某一个节点的位置:
                TreePath nodePath = new TreePath(treeModel.getPathToRoot(node));
                // 设置节点的展开选择和可见性:
                tree.setSelectionPath(nodePath);
                tree.makeVisible(nodePath);
                // 展开后滚动至节点可见:
                tree.scrollPathToVisible(nodePath);
                // 还有一个是设置鼠标点击展开树节点的(默认是双击,改成了0就是不可点击):
                tree.setToggleClickCount(1);
                // 另外就是一个设置Cell的高度的,但这个方法我们一般不用,大多时候是在Renderer里设置的,因为这样设置可能有UI问题:
                // tree.setRowHeight(15);
            }

        });
        // 树节点展开(折叠) 事件
        tree.addTreeExpansionListener(new TreeExpansionListener() {
            @Override
            public void treeExpanded(TreeExpansionEvent event) {
            }

            @Override
            public void treeCollapsed(TreeExpansionEvent event) {
            }

        });

        tree.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                if (SwingUtilities.isLeftMouseButton(e)
                        && e.getClickCount() == 1) {
                    // Returns the last path component
                    DefaultMutableTreeNode node = (DefaultMutableTreeNode) tree
                            .getLastSelectedPathComponent();
                } else if (SwingUtilities.isRightMouseButton(e)) {
                    // Returns the row for the specified location.
                    // int selectRow = tree.getRowForLocation(e.getX(),
                    // e.getY());
                    // Returns the path for the node at the specified location.
                    TreePath selectPath = tree.getPathForLocation(e.getX(),
                            e.getY());
                    if (selectPath != null) {
                        // set select
                        tree.setSelectionPath(selectPath);
                        // get tree node.
                        DefaultMutableTreeNode treeNode = (DefaultMutableTreeNode) selectPath
                                .getLastPathComponent();
                    }
                }
            }
        });

        // 渲染器
        tree.setCellRenderer(new DefaultTreeCellRenderer() {
            /**
             * serialVersionUID
             */
            private static final long serialVersionUID = 1L;

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

    /**
     * createTree
     * 
     * @return
     */
    private static JTree createTree() {
        // 创建没有父节点和子节点、但允许有子节点的树节点，并使用指定的用户对象对它进行初始化。
        // public DefaultMutableTreeNode(Object userObject)
        DefaultMutableTreeNode node1 = new DefaultMutableTreeNode("软件部");
        node1.add(new DefaultMutableTreeNode(new User("小花")));
        node1.add(new DefaultMutableTreeNode(new User("小虎")));
        node1.add(new DefaultMutableTreeNode(new User("小龙")));

        DefaultMutableTreeNode node2 = new DefaultMutableTreeNode("销售部");
        node2.add(new DefaultMutableTreeNode(new User("小叶")));
        node2.add(new DefaultMutableTreeNode(new User("小雯")));
        node2.add(new DefaultMutableTreeNode(new User("小夏")));

        DefaultMutableTreeNode top = new DefaultMutableTreeNode("职员管理");
        top.add(new DefaultMutableTreeNode(new User("总经理")));
        top.add(node1);
        top.add(node2);
        // JTree(TreeNode root)
        // 返回 JTree，指定的 TreeNode 作为其根，它显示根节点。
        JTree tree = new JTree(top);
        // 最终JTree也是通过setModel设置数据的:
        // tree = new JTree();
        // tree.setModel(treeModel);
        tree.getSelectionModel().setSelectionMode(
                TreeSelectionModel.SINGLE_TREE_SELECTION);
        return tree;
    }

    private List<TreeNode> treeNodeList = new ArrayList<TreeNode>();

    /**
     * 从任何节点递归其下所有的例子.
     * 
     * @param treeNode
     */
    public void getChildNodeList(TreeNode treeNode) {

        if (treeNode == null) {
            throw new RuntimeException("error treenode.");
        }

        if (treeNodeList == null) {
            treeNodeList = new ArrayList<TreeNode>();
        }

        if (treeNode.getChildCount() >= 0) {
            for (Enumeration<TreeNode> e = treeNode.children(); e
                    .hasMoreElements();) {
                TreeNode childNode = (TreeNode) e.nextElement();
                treeNodeList.add(childNode);
                getChildNodeList(childNode);
            }
        }
    }
}