Java 如何在树状路径上将一个节点插入另一个节点？

我在JavaSwing中有两个节点和一个树路径。 一个节点包含“根”节点（我们称之为nodeA），它包含它下面的所有内容。 第二个节点是“新”节点（我们称之为nodeB），它包含一个新节点。 我有一个树状路径，显示我想在nodeA中插入nodeB的位置。我正在尝试开发一个函数来实现这一点。有什么帮助吗？ 提前谢谢

Node A   
 ~
      Documents
         -- text1.txt
         -- text2.txt
      Pictures
         - text1.txt

我想将下面的节点插入图片文件夹

folder1
   -- newtext1.txt

My insertNodes函数：

private static void insertNodes
        (DefaultMutableTreeNode root
            ,DefaultMutableTreeNode newNode
                ,String tp)
{
    String[] elements = tp.split("/");
    String treePath = "";
    for (int i=0; i<elements.length-1; i++)
    {
        if (i == elements.length-2)
        {
            treePath += elements[i];
        } else {
        treePath += elements[i] + "/" ;
        }
    }
    System.out.println("TreePath : " + treePath);

    DefaultMutableTreeNode node = buildNodeFromString(treePath);
    DefaultMutableTreeNode lastLeaf = node.getLastLeaf();
    TreePath path = new TreePath(lastLeaf.getPath());
    System.out.println("insertNodes-Path =" + path);
    DefaultTreeModel model = new DefaultTreeModel(root);



    DefaultMutableTreeNode pictureNode = (DefaultMutableTreeNode) path.getLastPathComponent();
    pictureNode.add(newNode);





    // Notify the model of the changes
    model.nodesWereInserted(pictureNode, new int[]{pictureNode.getChildCount() - 1});

    // The above way (you suggested) wipes out everything and just puts one "~" in the JTree


    // The below line adds them all to the "~" direcotry
    //root.add(newNode); 


}

---

好的，一些假设，假设你有一个

TreeModel

，它看起来像这样

DefaultMutableTreeNode root = new DefaultMutableTreeNode("~");
DefaultTreeModel model = new DefaultTreeModel(root);

DefaultMutableTreeNode docs = new DefaultMutableTreeNode("Documents");
docs.add(new DefaultMutableTreeNode("text1.txt"));
docs.add(new DefaultMutableTreeNode("text2.txt"));
root.add(docs);

DefaultMutableTreeNode pics = new DefaultMutableTreeNode("Pictures");
pics.add(new DefaultMutableTreeNode("text1.txt"));
root.add(pics);

这将生成一棵看起来像

+ ~
  + Documents
    - text1.txt
    - text2.txt
  + Pictures
    - text1.txt

DefaultMutableTreeNode pictureNode = (DefaultMutableTreeNode) treePathFromPicturesToRoot.getLastPathComponent();
pictureNode.add(newFolder);

// Notify the model of the changes
model.nodesWereInserted(pictureNode, new int[]{pictureNode.getChildCount() - 1});

protected static DefaultMutableTreeNode findNode(DefaultTreeModel model, String path) {
    DefaultMutableTreeNode node = (DefaultMutableTreeNode) model.getRoot();
    String[] parts = path.split("/");
    if (node.getUserObject().toString().equals(parts[0])) {
         return findNode(node, Arrays.copyOfRange(parts, 1, parts.length));
    }
    return null;
}

protected static DefaultMutableTreeNode findNode(DefaultMutableTreeNode node, String[] path) {
    if (path.length == 0) {
        return node;
    }
    Enumeration<TreeNode> children = node.children();
    while (children.hasMoreElements()) {
        DefaultMutableTreeNode child = (DefaultMutableTreeNode)children.nextElement();
        if (child.getUserObject().toString().equals(path[0])) {
            return findNode(node, Arrays.copyOfRange(path, 1, path.length));
        }
    }
    return null;
}

DefaultMutableTreeNode newFolder = new DefaultMutableTreeNode("folder1");
newFolder.add(new DefaultMutableTreeNode("text1.txt"));

insertNodes(model, findNode(model, "~/Pictures"), newFolder);

然后，假设您知道要添加

DefaultMutableTreeNode newFolder = new DefaultMutableTreeNode("folder1");
newFolder.add(new DefaultMutableTreeNode("text1.txt"));

到

~/Pictures

假设您有一个有效的

TreePath

off

[~，Pictures]

，您只需从路径中获取

lastComponent

，该路径将是对

Pictures

TreeNode

的引用，然后您可以简单地执行以下操作

+ ~
  + Documents
    - text1.txt
    - text2.txt
  + Pictures
    - text1.txt

DefaultMutableTreeNode pictureNode = (DefaultMutableTreeNode) treePathFromPicturesToRoot.getLastPathComponent();
pictureNode.add(newFolder);

// Notify the model of the changes
model.nodesWereInserted(pictureNode, new int[]{pictureNode.getChildCount() - 1});

protected static DefaultMutableTreeNode findNode(DefaultTreeModel model, String path) {
    DefaultMutableTreeNode node = (DefaultMutableTreeNode) model.getRoot();
    String[] parts = path.split("/");
    if (node.getUserObject().toString().equals(parts[0])) {
         return findNode(node, Arrays.copyOfRange(parts, 1, parts.length));
    }
    return null;
}

protected static DefaultMutableTreeNode findNode(DefaultMutableTreeNode node, String[] path) {
    if (path.length == 0) {
        return node;
    }
    Enumeration<TreeNode> children = node.children();
    while (children.hasMoreElements()) {
        DefaultMutableTreeNode child = (DefaultMutableTreeNode)children.nextElement();
        if (child.getUserObject().toString().equals(path[0])) {
            return findNode(node, Arrays.copyOfRange(path, 1, path.length));
        }
    }
    return null;
}

DefaultMutableTreeNode newFolder = new DefaultMutableTreeNode("folder1");
newFolder.add(new DefaultMutableTreeNode("text1.txt"));

insertNodes(model, findNode(model, "~/Pictures"), newFolder);

这将生成一棵像

+ ~
  + Documents
    - text1.txt
    - text2.txt
  + Pictures
    - text1.txt
    + folder1
      - text1.txt

现在，我不知道

TreePath

是从哪里来的，但我假设它是由

TreeModel

中实际存在的节点组成的有效路径，否则这将无法正常工作

现在，这是基于一些例子，如果这不能满足您的需求，那么您需要提供一个我们可以更好地理解您的问题的

示例代码。。。 我使用以下代码构建了基本概念

import java.util.Enumeration;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreeNode;
import javax.swing.tree.TreePath;

public class Test {

    public static void main(String[] args) {
        DefaultMutableTreeNode root = new DefaultMutableTreeNode("~");
        DefaultTreeModel model = new DefaultTreeModel(root);

        DefaultMutableTreeNode docs = new DefaultMutableTreeNode("Documents");
        docs.add(new DefaultMutableTreeNode("text1.txt"));
        docs.add(new DefaultMutableTreeNode("text2.txt"));
        root.add(docs);

        DefaultMutableTreeNode pics = new DefaultMutableTreeNode("Pictures");
        pics.add(new DefaultMutableTreeNode("text1.txt"));
        root.add(pics);

        describe(model);

        DefaultMutableTreeNode newFolder = new DefaultMutableTreeNode("folder1");
        newFolder.add(new DefaultMutableTreeNode("text1.txt"));

        TreeNode[] pathToRoot = pics.getPath();
        TreePath treePathFromPicturesToRoot = new TreePath(pathToRoot);
        System.out.println(treePathFromPicturesToRoot);

        DefaultMutableTreeNode pictureNode = (DefaultMutableTreeNode) treePathFromPicturesToRoot.getLastPathComponent();
        pictureNode.add(newFolder);

        model.nodesWereInserted(pictureNode, new int[]{pictureNode.getChildCount() - 1});

        describe(model);
    }

    protected static void describe(DefaultTreeModel model) {
        describe((DefaultMutableTreeNode) model.getRoot(), 0);
    }

    protected static void describe(DefaultMutableTreeNode node, int level) {
        StringBuilder padding = new StringBuilder();
        for (int index = 0; index < level; index++) {
            padding.append("  ");
        }
        System.out.println(padding + "+ " + node);
        padding.append("  ");
        Enumeration<TreeNode> children = node.children();
        while (children.hasMoreElements()) {
            DefaultMutableTreeNode childNode = (DefaultMutableTreeNode) children.nextElement();
            if (childNode.isLeaf()) {
                System.out.println(padding + "- " + childNode);
            } else {
                describe(childNode, level + 1);
            }
        }
    }
}

要根据

字符串
路径查找节点，您“可能”可以执行以下操作

+ ~
  + Documents
    - text1.txt
    - text2.txt
  + Pictures
    - text1.txt

DefaultMutableTreeNode pictureNode = (DefaultMutableTreeNode) treePathFromPicturesToRoot.getLastPathComponent();
pictureNode.add(newFolder);

// Notify the model of the changes
model.nodesWereInserted(pictureNode, new int[]{pictureNode.getChildCount() - 1});

protected static DefaultMutableTreeNode findNode(DefaultTreeModel model, String path) {
    DefaultMutableTreeNode node = (DefaultMutableTreeNode) model.getRoot();
    String[] parts = path.split("/");
    if (node.getUserObject().toString().equals(parts[0])) {
         return findNode(node, Arrays.copyOfRange(parts, 1, parts.length));
    }
    return null;
}

protected static DefaultMutableTreeNode findNode(DefaultMutableTreeNode node, String[] path) {
    if (path.length == 0) {
        return node;
    }
    Enumeration<TreeNode> children = node.children();
    while (children.hasMoreElements()) {
        DefaultMutableTreeNode child = (DefaultMutableTreeNode)children.nextElement();
        if (child.getUserObject().toString().equals(path[0])) {
            return findNode(node, Arrays.copyOfRange(path, 1, path.length));
        }
    }
    return null;
}

DefaultMutableTreeNode newFolder = new DefaultMutableTreeNode("folder1");
newFolder.add(new DefaultMutableTreeNode("text1.txt"));

insertNodes(model, findNode(model, "~/Pictures"), newFolder);

样本#2
导入java.util.array；
导入java.util.Enumeration；
导入javax.swing.tree.DefaultMutableTreeNode；
导入javax.swing.tree.DefaultTreeModel；
导入javax.swing.tree.TreeNode；
公开课考试{
公共静态void main（字符串[]args）{
DefaultMutableTreeNode根=新的DefaultMutableTreeNode（“~”）；
DefaultTreeModel模型=新的DefaultTreeModel（根）；
DefaultMutableTreeNode文档=新的DefaultMutableTreeNode（“文档”）；
添加（新的DefaultMutableTreeNode（“text1.txt”）；
添加（新的DefaultMutableTreeNode（“text2.txt”）；
root.add（文档）；
DefaultMutableTreeNode pics=新的DefaultMutableTreeNode（“图片”）；
添加（新的DefaultMutableTreeNode（“text1.txt”）；
根。添加（pics）；
描述（模型）；
DefaultMutableTreeNode newFolder=新的DefaultMutableTreeNode（“folder1”）；
添加（新的DefaultMutableTreeNode（“text1.txt”）；
插入节点（model，findNode（model，~/Pictures），newFolder）；
描述（模型）；
}
受保护的静态DefaultMutableTreeNode findNode（DefaultTreeModel模型，字符串路径）{
DefaultMutableTreeNode=（DefaultMutableTreeNode）model.getRoot（）；
String[]parts=path.split（“/”）；
if（node.getUserObject（）.toString（）.equals（parts[0]））{
返回findNode（节点、数组、copyOfRange（parts、1、parts.length））；
}
返回null；
}
受保护的静态DefaultMutableTreeNode findNode（DefaultMutableTreeNode节点，字符串[]路径）{
if（path.length==0）{
返回节点；
}
枚举子节点=node.children（）；
while（children.hasMoreElements（））{
DefaultMutableTreeNode子项=（DefaultMutableTreeNode）子项。nextElement（）；
if（child.getUserObject（）.toString（）.equals（路径[0]））{
返回findNode（child，Arrays.copyOfRange（path，1，path.length））；
}
}
返回null；
}
私有静态void insertNodes(
DefaultTreeModel模型，
DefaultMutableTreeNode父级，
DefaultMutableTreeNode（新节点）{
parent.add（newNode）；
nodesWereInserted（父，新int[]{parent.getChildCount（）-1}）；
}
受保护的静态无效描述（DefaultTreeModel模型）{
描述（（DefaultMutableTreeNode）model.getRoot（），0）；
}
受保护的静态无效描述（DefaultMutableTreeNode节点，int级别）{
StringBuilder padding=新的StringBuilder（）；
对于（int index=0；index
So@MadProgrammer感谢您的代码，我很感激，但这似乎不起作用，我将向您提供更多信息，我将更新我的代码以反映我用于插入节点的功能，因为我的代码显然有效-您必须提供一个完整且可运行的示例，否则，我们将继续在猜测的圈子里转来转去，这只会浪费彼此的时间。嗯，好的，我可以给你链接一个github文件吗？它有完整的代码？不，请阅读并理解-这是一个常见的要求，1-帮助人们理解您的代码和您的问题，2-帮助社区评估提供的回答的价值。我更新了我的代码，将调用insertNodes（）的函数包含在内；如果没有我的GUI功能，它是不可复制的，但是因为您只需要该功能的核心功能，所以我用它更新了我的问题