节点增删改

public class Tree extends JFrame{JTextField textField;public Tree(){//构造方法DefaultMutableTreeNode root=new DefaultMutableTreeNode("根节点");DefaultMutableTreeNode nodeFirst=new DefaultMutableTreeNode("一级子节点A");root.add(nodeFirst);DefaultMutableTreeNode nodeSecond=new DefaultMutableTreeNode("二级子节点a");nodeFirst.add(nodeSecond);DefaultMutableTreeNode nodeThree=new DefaultMutableTreeNode("三级子节点");nodeSecond.add(nodeThree);DefaultMutableTreeNode nodeFirst2=new DefaultMutableTreeNode("一级子节点B");root.add(nodeFirst2);DefaultMutableTreeNode nodeSecond2=new DefaultMutableTreeNode("二级子节点b"); nodeFirst2.add(nodeSecond2);;JTree treeRoot=new JTree(root);//利用根节点直接创建树/*treeRoot.setRootVisible(false);//不显示树的根节点treeRoot.setRowHeight(20);//树节点行高treeRoot.setFont(new Font("宋体",Font.BOLD,14));//设置树节点字体treeRoot.putClientProperty("JTree.lineStyle","None");//节点间不采用连线DefaultTreeCellRenderer treeCellRenderer=(DefaultTreeCellRenderer)treeRoot.getCellRenderer();//获得树节点的绘制对象treeCellRenderer.setLeafIcon(null);//设置叶子节点不采用图标treeCellRenderer.setClosedIcon(null);//设置节点折叠是不采用图标treeCellRenderer.setOpenIcon(null);//设置节点展开是不采用图标Enumeration enumeration=root.preorderEnumeration();//按前序遍历所有树节点while(enumeration.hasMoreElements()){DefaultMutableTreeNode node=(DefaultMutableTreeNode)enumeration.nextElement();if(!node.isLeaf()){TreePath path=new TreePath(node.getPath());//创建该节点的路径treeRoot.expandPath(path);//如果不是叶子节点则展开该节点}}*/DefaultTreeModel treeModel=new DefaultTreeModel(root);//利用根节点创建树模型自己判断getContentPane().add(treeRoot, BorderLayout.CENTER);final JButton addButton=new JButton("添加");textField=new JTextField(20);addButton.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e){DefaultMutableTreeNode node=new DefaultMutableTreeNode(textField.getText());//创建想添加节点TreePath selectionPath=treeRoot.getSelectionPath();//获得选中的父节点路径DefaultMutableTreeNode parentNode=(DefaultMutableTreeNode)selectionPath.getLastPathComponent();//获得选中的父节点treeModel.insertNodeInto(node,parentNode,parentNode.getChildCount());//插入节点到所有节点的么节点TreePath path=selectionPath.pathByAddingChild(node);//获得新添加新节点路径if(!treeRoot.isVisible(path))treeRoot.makeVisible(path);//如果不可见零他可见}});JPanel panel=new JPanel();panel.add(addButton);final JButton updButton=new JButton("修改");updButton.addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e){TreePath selectionPath=treeRoot.getSelectionPath();//获得选中的想修改的节点路径DefaultMutableTreeNode node=(DefaultMutableTreeNode)selectionPath.getLastPathComponent();//获得选中的想修改的节点node.setUserObject(textField.getText());//修改阶段的用户treeModel.nodeChanged(node);//通知树模型该节点已被修改TreePath path=selectionPath.pathByAddingChild(node);if(!treeRoot.isVisible(path)){treeRoot.makeVisible(path);}treeRoot.setSelectionPath(selectionPath);//选中被修改的节点}});panel.add(updButton);final JButton delButton=new JButton("删除");delButton.addActionListener(new ActionListener(){public void actionPerformd(ActionEvent e){DefaultMutableTreeNode node=(DefaultMutableTreeNode)treeRoot.getLastSelectedPathComponent();//获得向北删除的节点//查看想删除的是否为根节点，根节点不允许删除if(!node.isRoot()){DefaultMutableTreeNode nextSelectedNode=node.getNextSibling();//获得下一个兄弟节点已被选中if(nextSelectedNode==null){//查看是否存在nextSelectedNode=(DefaultMutableTreeNode)node.getParent();treeModel.removeNodeFromParent(node);//删除节点TreePath selectionPath=treeRoot.getSelectionPath();//获得选中的父节点路径treeRoot.setSelectionPath(new TreePath(nextSelectedNode.getPath()));TreePath path=selectionPath.pathByAddingChild(node);if(!treeRoot.isVisible(path)){treeRoot.makeVisible(path);}treeRoot.setSelectionPath(selectionPath);//选中被修改的节点}}}@Overridepublic void actionPerformed(ActionEvent arg0) {// TODO Auto-generated method stub}});panel.add(delButton);textField.setBounds(0,220,50,20);getContentPane().add(textField,BorderLayout.SOUTH);getContentPane().add(panel, BorderLayout.SOUTH);setSize(300,300);setVisible(true);setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);}public static void main(String[] args) { new Tree();} }