从JTree Transferable TransferHandler复制粘贴

我正在探索如何实现JTree的Copy和Paste 。

因为，我希望从DefaultMutableTreeNode复制像toString()一样粘贴到另一个应用程序，如Sublime Text。

我正在查看代码，以便查看如何实现复制和粘贴以及如何在JTree中使用拖放 。

我的第一个问题是，必须测试JTree DefaultMutableTreeNode之间的复制和粘贴，以后如何从剪贴板粘贴到另一个应用程序，但是我的代码不能正常工作并且不知道为什么会失败，我需要解决。

注意 ：对不起，我的代码有点长，因为如果我只放一个代码片段则不起作用。 对我来说，这里的所有代码都需要进行测试。

这是我的代码：

 import java.awt.*; import java.awt.datatransfer.*; import java.awt.event.ActionEvent; import java.util.*; import javax.swing.*; import javax.swing.tree.*; public class JTreeTransferHandler extends JFrame { public JTreeTransferHandler() { initiate(); } private void initiate() { setTitle("Copy from JTree"); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setSize(400,400); setLocation(200,200); setVisible(true); DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root"); DefaultMutableTreeNode vegetableNode = new DefaultMutableTreeNode("Vegetables"); vegetableNode.add(new DefaultMutableTreeNode("Capsicum")); vegetableNode.add(new DefaultMutableTreeNode("Carrot")); DefaultMutableTreeNode fruitNode = new DefaultMutableTreeNode("Fruits"); fruitNode.add(new DefaultMutableTreeNode("Mango")); fruitNode.add(new DefaultMutableTreeNode("Apple")); root.add(vegetableNode); root.add(fruitNode); JTree tree = new JTree(root); TreeTransferHandler treeTransferHandler = new TreeTransferHandler(); tree.setTransferHandler(treeTransferHandler); Clipboard clipboard = this.getToolkit().getSystemClipboard(); JButton copy = new JButton("Copy"); copy.addActionListener((ActionEvent e) -> { TransferHandler handler = tree.getTransferHandler(); handler.exportToClipboard(tree, clipboard, TransferHandler.COPY); }); JButton paste = new JButton("Paste"); paste.addActionListener((ActionEvent e) -> { Transferable clipData = clipboard.getContents(clipboard); if (clipData != null) { if (clipData.isDataFlavorSupported(treeTransferHandler.nodesFlavor)) { TransferHandler handler = tree.getTransferHandler(); handler.importData(tree, clipData); } } }); JPanel buttonsPanel = new JPanel(); buttonsPanel.add(copy); buttonsPanel.add(paste); add(new JScrollPane(tree), BorderLayout.CENTER); add(buttonsPanel, BorderLayout.SOUTH); } public static void main(String[] args) { SwingUtilities.invokeLater(() -> { JTreeTransferHandler jTreeTransferHandler = new JTreeTransferHandler(); }); } } class TreeTransferHandler extends TransferHandler { DataFlavor nodesFlavor; DataFlavor[] flavors = new DataFlavor[1]; DefaultMutableTreeNode[] nodesToRemove; public TreeTransferHandler() { try { String mimeType = DataFlavor.javaJVMLocalObjectMimeType + ";class=\"" + DefaultMutableTreeNode[].class.getName() + "\""; nodesFlavor = new DataFlavor(mimeType); flavors[0] = nodesFlavor; } catch(ClassNotFoundException e) { System.out.println("ClassNotFound: " + e.getMessage()); } } //TransferHandler @Override public int getSourceActions(JComponent c) { return TransferHandler.COPY; } //TransferHandler @Override public boolean canImport(JComponent comp, DataFlavor flavor[]) { for (int i = 0, n = flavor.length; i < n; i++) { for (int j = 0, m = flavors.length; j < m; j++) { if (flavor[i].equals(flavors[j])) { return true; } } } return false; } //TransferHandler @Override protected Transferable createTransferable(JComponent c) { JTree tree = (JTree) c; TreePath[] paths = tree.getSelectionPaths(); if (paths != null) { List copies = new ArrayList(); List toRemove = new ArrayList(); DefaultMutableTreeNode node = (DefaultMutableTreeNode) paths[0].getLastPathComponent(); DefaultMutableTreeNode copy = copy(node); copies.add(copy); toRemove.add(node); for (int i = 1; i < paths.length; i++) { DefaultMutableTreeNode next = (DefaultMutableTreeNode) paths[i].getLastPathComponent(); // Do not allow higher level nodes to be added to list. if (next.getLevel()  node.getLevel()) { // child node copy.add(copy(next)); // node already contains child } else { // sibling copies.add(copy(next)); toRemove.add(next); } } DefaultMutableTreeNode[] nodes = copies.toArray(new DefaultMutableTreeNode[copies.size()]); nodesToRemove = toRemove.toArray(new DefaultMutableTreeNode[toRemove.size()]); return new NodesTransferable(nodes); } return null; } /** Defensive copy used in createTransferable. */ private DefaultMutableTreeNode copy(TreeNode node) { return new DefaultMutableTreeNode(node); } //TransferHandler @Override public boolean importData(TransferHandler.TransferSupport support) { if (!canImport(support)) { return false; } // Extract transfer data. DefaultMutableTreeNode[] nodes = null; try { Transferable t = support.getTransferable(); nodes = (DefaultMutableTreeNode[]) t.getTransferData(nodesFlavor); } catch (UnsupportedFlavorException ufe) { System.out.println("UnsupportedFlavor: " + ufe.getMessage()); } catch (java.io.IOException ioe) { System.out.println("I/O error: " + ioe.getMessage()); } // Get drop location info. JTree.DropLocation dl = (JTree.DropLocation) support.getDropLocation(); int childIndex = dl.getChildIndex(); TreePath dest = dl.getPath(); DefaultMutableTreeNode parent = (DefaultMutableTreeNode) dest.getLastPathComponent(); JTree tree = (JTree) support.getComponent(); DefaultTreeModel model = (DefaultTreeModel) tree.getModel(); // Configure for drop mode. int index = childIndex; // DropMode.INSERT if (childIndex == -1) { // DropMode.ON index = parent.getChildCount(); } // Add data to model. for (int i = 0; i < nodes.length; i++) { model.insertNodeInto(nodes[i], parent, index++); } return true; } //TransferHandler public boolean importData(JComponent comp, Transferable t) { // Extract transfer data. DefaultMutableTreeNode[] nodes; try { nodes = (DefaultMutableTreeNode[]) t.getTransferData(nodesFlavor); if (comp instanceof JTree) { JTree tree = (JTree)comp; DefaultTreeModel model = (DefaultTreeModel) tree.getModel(); JTree.DropLocation dl = tree.getDropLocation(); int childIndex = dl.getChildIndex(); TreePath dest = dl.getPath(); DefaultMutableTreeNode parent = (DefaultMutableTreeNode)dest.getLastPathComponent(); // Configure for drop mode. int index = childIndex; // DropMode.INSERT if (childIndex == -1) { // DropMode.ON index = parent.getChildCount(); } // Add data to model. for (DefaultMutableTreeNode node : nodes) { model.insertNodeInto(node, parent, index++); } return true; } } catch (UnsupportedFlavorException ufe) { System.out.println("UnsupportedFlavor: " + ufe.getMessage()); } catch (java.io.IOException ioe) { System.out.println("I/O error: " + ioe.getMessage()); } return false; } public class NodesTransferable implements Transferable { DefaultMutableTreeNode[] nodes; public NodesTransferable(DefaultMutableTreeNode[] nodes) { this.nodes = nodes; } //Transferable @Override public Object getTransferData(DataFlavor flavor) { if(!isDataFlavorSupported(flavor)) { return false; } return nodes; } //Transferable @Override public DataFlavor[] getTransferDataFlavors() { return flavors; } //Transferable @Override public boolean isDataFlavorSupported(DataFlavor flavor) { return flavor.equals(nodesFlavor); } } } 

Answer 1

TransferHandler.TransferSupport＃isDrop（）方法在via Clipboard的情况下返回false ，所以在这里切换它似乎工作正常。

 // Get drop location info. int childIndex; TreePath dest; if (support.isDrop()) { JTree.DropLocation dl = (JTree.DropLocation) support.getDropLocation(); childIndex = dl.getChildIndex(); dest = dl.getPath(); } else { childIndex = -1; JTree tree = (JTree) support.getComponent(); dest = tree.getSelectionPath(); } 

JTreeTransferHandler2.java

 import java.awt.*; import java.awt.datatransfer.*; import java.awt.event.ActionEvent; import java.util.*; import java.util.List; import javax.swing.*; import javax.swing.tree.*; public class JTreeTransferHandler2 extends JFrame { public JTreeTransferHandler2() { initiate(); } private void initiate() { setTitle("Copy from JTree"); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setSize(400,400); setLocation(200,200); setVisible(true); DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root"); DefaultMutableTreeNode vegetableNode = new DefaultMutableTreeNode("Vegetables"); vegetableNode.add(new DefaultMutableTreeNode("Capsicum")); vegetableNode.add(new DefaultMutableTreeNode("Carrot")); DefaultMutableTreeNode fruitNode = new DefaultMutableTreeNode("Fruits"); fruitNode.add(new DefaultMutableTreeNode("Mango")); fruitNode.add(new DefaultMutableTreeNode("Apple")); root.add(vegetableNode); root.add(fruitNode); JTree tree = new JTree(root); TreeTransferHandler treeTransferHandler = new TreeTransferHandler(); tree.setTransferHandler(treeTransferHandler); Clipboard clipboard = this.getToolkit().getSystemClipboard(); JButton copy = new JButton("Copy"); copy.addActionListener((ActionEvent e) -> { TransferHandler handler = tree.getTransferHandler(); handler.exportToClipboard(tree, clipboard, TransferHandler.COPY); }); JButton paste = new JButton("Paste"); paste.addActionListener((ActionEvent e) -> { Transferable clipData = clipboard.getContents(null); if (clipData != null) { if (clipData.isDataFlavorSupported(treeTransferHandler.nodesFlavor)) { TransferHandler handler = tree.getTransferHandler(); handler.importData(tree, clipData); } } }); JPanel buttonsPanel = new JPanel(); buttonsPanel.add(copy); buttonsPanel.add(paste); add(new JScrollPane(tree), BorderLayout.CENTER); add(buttonsPanel, BorderLayout.SOUTH); } public static void main(String[] args) { SwingUtilities.invokeLater(() -> { JTreeTransferHandler2 jTreeTransferHandler = new JTreeTransferHandler2(); }); } } class TreeTransferHandler extends TransferHandler { DataFlavor nodesFlavor; DataFlavor[] flavors = new DataFlavor[1]; DefaultMutableTreeNode[] nodesToRemove; public TreeTransferHandler() { try { String mimeType = DataFlavor.javaJVMLocalObjectMimeType + ";class=\"" + DefaultMutableTreeNode[].class.getName() + "\""; nodesFlavor = new DataFlavor(mimeType); flavors[0] = nodesFlavor; } catch(ClassNotFoundException e) { System.out.println("ClassNotFound: " + e.getMessage()); } } //TransferHandler @Override public int getSourceActions(JComponent c) { return TransferHandler.COPY; } //TransferHandler @Override public boolean canImport(JComponent comp, DataFlavor flavor[]) { for (int i = 0, n = flavor.length; i < n; i++) { for (int j = 0, m = flavors.length; j < m; j++) { if (flavor[i].equals(flavors[j])) { return true; } } } return false; } //TransferHandler @Override protected Transferable createTransferable(JComponent c) { JTree tree = (JTree) c; TreePath[] paths = tree.getSelectionPaths(); if (paths != null) { List copies = new ArrayList<>(); List toRemove = new ArrayList<>(); DefaultMutableTreeNode node = (DefaultMutableTreeNode) paths[0].getLastPathComponent(); DefaultMutableTreeNode copy = copy(node); copies.add(copy); toRemove.add(node); for (int i = 1; i < paths.length; i++) { DefaultMutableTreeNode next = (DefaultMutableTreeNode) paths[i].getLastPathComponent(); // Do not allow higher level nodes to be added to list. if (next.getLevel() < node.getLevel()) { break; } else if (next.getLevel() > node.getLevel()) { // child node copy.add(copy(next)); // node already contains child } else { // sibling copies.add(copy(next)); toRemove.add(next); } } DefaultMutableTreeNode[] nodes = copies.toArray(new DefaultMutableTreeNode[copies.size()]); nodesToRemove = toRemove.toArray(new DefaultMutableTreeNode[toRemove.size()]); return new NodesTransferable(nodes); } return null; } /** Defensive copy used in createTransferable. */ private DefaultMutableTreeNode copy(TreeNode node) { return new DefaultMutableTreeNode(node); } //TransferHandler @Override public boolean importData(TransferHandler.TransferSupport support) { if (!canImport(support)) { return false; } // Extract transfer data. DefaultMutableTreeNode[] nodes = null; try { Transferable t = support.getTransferable(); nodes = (DefaultMutableTreeNode[]) t.getTransferData(nodesFlavor); } catch (UnsupportedFlavorException ufe) { System.out.println("UnsupportedFlavor: " + ufe.getMessage()); } catch (java.io.IOException ioe) { System.out.println("I/O error: " + ioe.getMessage()); } // Get drop location info. int childIndex; TreePath dest; if (support.isDrop()) { JTree.DropLocation dl = (JTree.DropLocation) support.getDropLocation(); childIndex = dl.getChildIndex(); dest = dl.getPath(); } else { childIndex = -1; JTree tree = (JTree) support.getComponent(); dest = tree.getSelectionPath(); } DefaultMutableTreeNode parent = (DefaultMutableTreeNode) dest.getLastPathComponent(); JTree tree = (JTree) support.getComponent(); DefaultTreeModel model = (DefaultTreeModel) tree.getModel(); // Configure for drop mode. int index = childIndex; // DropMode.INSERT if (childIndex == -1) { // DropMode.ON index = parent.getChildCount(); } // Add data to model. for (int i = 0; i < nodes.length; i++) { // ArrayIndexOutOfBoundsException model.insertNodeInto(nodes[i], parent, index++); } return true; } //TransferHandler @Override public boolean importData(JComponent comp, Transferable t) { return importData(new TransferHandler.TransferSupport(comp, t)); } public class NodesTransferable implements Transferable { DefaultMutableTreeNode[] nodes; public NodesTransferable(DefaultMutableTreeNode[] nodes) { this.nodes = nodes; } //Transferable @Override public Object getTransferData(DataFlavor flavor) { if(!isDataFlavorSupported(flavor)) { return false; } return nodes; } //Transferable @Override public DataFlavor[] getTransferDataFlavors() { return flavors; } //Transferable @Override public boolean isDataFlavorSupported(DataFlavor flavor) { return flavor.equals(nodesFlavor); } } }