您如何创建一个javafilelist风味对象以放入JList中？

Question

我的应用程序中并排有一个JTree和JList。当我将节点从JTree拖到JList时，我已添加到List的节点

System.out.println（Arrays.toString（info.getTransferable（）.getTransferDataFlavors（））

返回：

[javax.activation.ActivationDataFlavor[mimetype=application/x-java-jvm-local-objectref；representationclass=java.io.InputStream]

我如何才能让我的JList接受我的Jtree的投递？我试图创建自己的dataflavor，但没有成功——这在我粘贴的代码中被注释掉了。

  static class ListTransferHandler extends TransferHandler {

    Logger lgs = null;

    int action;

    public ListTransferHandler(int action) {
        this.action = action;
        lgs = Logger.getLogger("ListTransferHandler Logger");
        lgs.setLevel(ALL);
        lgs.log(Level.INFO, "ListTransferHandler object created");
    }

    @Override
    public boolean canImport(TransferHandler.TransferSupport info) {
        //  lgs.log(Level.INFO, "can import called");

        if (!info.isDrop()) {
            return false;
        }

        info.setShowDropLocation(true);

        System.out.println(Arrays.toString(info.getTransferable().getTransferDataFlavors()));

        if (!info.isDataFlavorSupported(DataFlavor.javaFileListFlavor)) {
            lgs.log(Level.INFO, "Flavor not supported");
            return false;
        } else {
            lgs.log(Level.INFO, "Flavor supported");
        }

        boolean actionSupported = (action & info.getSourceDropActions()) == action;

        if (!actionSupported) {
            info.setDropAction(action);
            return false;
        }

        return true;

    }

    @Override
    public boolean importData(TransferHandler.TransferSupport support) {

        if (!canImport(support)) {
            return false;
        }

        JList.DropLocation dl = (JList.DropLocation) support.getDropLocation();

        int index = dl.getIndex();

        List<File> fileList;

        try {
            fileList = (List) support.getTransferable().getTransferData(DataFlavor.javaFileListFlavor);
        } catch (UnsupportedFlavorException | java.io.IOException e) {
            return false;
        }

        JList list = (JList) support.getComponent();
        DefaultListModel model = (DefaultListModel) list.getModel();
        //insertElementAt(data, index);

        for (File file : fileList) {
            model.addElement(file.getName());
        }

        return true;
    }
}

static class SelectedFileTransferHandler extends TransferHandler {

    //private DataFlavor localObjectFlavor = new DataFlavor( List.class, "Array of items");
    Logger lgs = null;

    public SelectedFileTransferHandler() {
        lgs = Logger.getLogger("SelectedFileTransferHandler Logger");
        lgs.setLevel(ALL);
        //  lgs.log(Level.INFO, "Tranfer object created");

    }

    @Override
    public int getSourceActions(JComponent comp) {
        // lgs.log(Level.INFO, "got source actions");
        return COPY;
    }

    @Override
    public Transferable createTransferable(JComponent comp) {
        //  lgs.log(Level.INFO, "creating tranferable");
        JTree tree = (JTree) comp;
        TreePath[] paths = tree.getSelectionPaths();
        List<File> nodesAsFiles = null;

        if (paths != null) {
            nodesAsFiles = new ArrayList<File>();
            for (TreePath path : paths) {
                nodesAsFiles.add((File) path.getLastPathComponent());
            }

            //File node = (File) paths.getLastPathComponent();
            //  copies.add(node);
            for (File file : nodesAsFiles) {
                System.out.println(file.getPath());
            }

        }
        List<File> defensiveCopyOfNodesAsFiles = null;
        if (nodesAsFiles != null) {
            defensiveCopyOfNodesAsFiles = new ArrayList(nodesAsFiles);
        }
        return new DataHandler(defensiveCopyOfNodesAsFiles, javaJVMLocalObjectMimeType);
        //return new DataHandler(transferedObjects, localObjectFlavor.getMimeType());
    }

}




Answer 1

我很惊讶，我找不到一种方法将我的JTree中的文件列表制作成javaFileListFlavorDataFlavor以传递给我的JList的filehandler的canimport和import Data方法。为了解决我的问题，我创建了一个自定义DataFlavor，如类中所示，ArrayListTransferHandler.java。

当在JTree的传输处理程序中调用createTransportable（）时，它将把一个List对象传递给实现Transportable的类。后者返回自定义DataFlavor的可转移。我还没有完成所有的构建，但是上面代码中的代码示例（根据我的日志）似乎已经解决了我的问题。Jlist现在正在接受我想要发送的数据。