Java：從ArrayList構建JTree <String>

Question

我得到了一個包含不同文件路徑的ArrayList，如下所示：

ArrayList<String> test = new ArrayList<String>();
test.add("/Test/blah.txt");
test.add("/Test/folder/1.txt");
test.add("/Test/folder/2.txt");
test.add("/Test/folder/3.txt");
test.add("/Test/folder/folder2/1.txt");
test.add("/Test/folder/folder2/2.txt");
test.add("/Test/folder/folder2/3.txt");

有沒有辦法從該數組構建JTree？ 我已經嘗試將此ArrayList轉換為Vector或Hashtable。 但它從未真正按預期工作。

也許有人有一個好主意來處理這個問題。 問候

Answer 1

我正在為您的問題發布類似的代碼。希望您對此有所幫助。...

public class Main {
  public static void main(String[] args) {
    JTree tree = new JTree(new TestModel());
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setLayout(new BorderLayout());
    frame.add(new JScrollPane(tree));
    frame.pack();
    frame.setVisible(true);
  }
}
class TestModel implements TreeModel {

  Element data;

  TestModel() {
    data = new Element("data");
    data.add(new Element("One"));
    data.add(new Element("Two"));
    data.add(new Element("Three"));
    data.add(new Element("Four"));
    data.add(new Element("Five"));
  }
  @Override
  public Object getRoot() {
    return data;
  }

  @Override
  public Object getChild(Object parent, int index) {

    System.out.println("GetChild from " + parent + " @ " + index);

    if (parent instanceof Element) {
      Element p = (Element) parent;
      Object child = p.getChildAt(index);

      System.out.println("child = " + child);
      return child;
    }
    return null;
  }

  @Override
  public int getChildCount(Object parent) {
    if (parent instanceof Element) {
      Element e = (Element) parent;
      System.out.println("childCount = " + parent + "; " + e.getChildCount());
      return e.getChildCount();
    }
    return 0;
  }
  @Override
  public int getIndexOfChild(Object parent, Object child) {
    if (parent instanceof Element && child instanceof Element) {
      Element e = (Element) parent;
      System.out.println("indexOf " + child + " in " + parent + " is "
          + e.getIndex((Element) child));
      return e.getIndex((Element) child);
    }
    return -1;
  }
  @Override
  public boolean isLeaf(Object node) {
    if (node instanceof Element) {
      Element e = (Element) node;
      System.out.println("isLeaf " + e + "; " + (e.getChildCount() == 0));
      return e.getChildCount() == 0;
    }
    return true;
  }
  @Override
  public void valueForPathChanged(TreePath path, Object newValue) {
  }
  @Override
  public void addTreeModelListener(TreeModelListener l) {
  }
  @Override
  public void removeTreeModelListener(TreeModelListener l) {
  }
}
class Element implements TreeNode {
  List<Element> nodes;
  Element parent;
  String name;
  public Element(String n) {
    nodes = new ArrayList<>(25);
    name = n;
  }

  @Override
  public String toString() {
    return name;
  }
  protected void setParent(Element parent) {
    this.parent = parent;
  }
  public void add(Element node) {
    node.setParent(this);
    nodes.add(node);
  }
  public void remove(Element node) {
    node.setParent(null);
    nodes.remove(node);
  }

  @Override
  public TreeNode getChildAt(int childIndex) {
    return nodes.get(childIndex);
  }

  @Override
  public int getChildCount() {
    return nodes.size();
  }

  @Override
  public TreeNode getParent() {
    return parent;
  }

  @Override
  public int getIndex(TreeNode node) {
    return nodes.indexOf(node);
  }

  @Override
  public boolean getAllowsChildren() {
    return true;
  }

  @Override
  public boolean isLeaf() {
    return nodes.isEmpty();
  }

  @Override
  public Enumeration children() {
    return Collections.enumeration(nodes);
  }
}

Answer 2

這是接近你的問題但在數組中完成的另一個過程..

import javax.swing.*;
import javax.swing.tree.*;
import java.awt.Container;
import java.awt.GridLayout;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import java.util.Enumeration;

public class DICTest extends JPanel{
    String[] str={"test", "test","test\\TP1","test\\TP1",
            "test\\TP1\\TP2","test\\TP1\\TP2\\TP3","test\\T1"
            };
    String[] conn_name={"test1","test2","tp1_test1","tp1_test2","tp2_test1","tp3_test1","t1_test1"};
    public DICTest(JFrame frame) {  


        DefaultMutableTreeNode master = new DefaultMutableTreeNode("Root");
        JTree tree = new JTree(master);
         JScrollPane scroll = new JScrollPane(tree);
         this.setSize(200,400);
        for(int i=0;i<str.length;i++){
            root=DrawTree(str[i],root,conn_name[i]);
        }      

        add(scroll);
    }



     public static DefaultMutableTreeNode DrawTree(String directory, DefaultMutableTreeNode parent, String conn_name) {
         DefaultMutableTreeNode node =new DefaultMutableTreeNode();
         DefaultMutableTreeNode conn_Node =new DefaultMutableTreeNode();
         System.out.println("Directory .... "+directory);


         if(directory.equalsIgnoreCase("Connections")){
             conn_Node = new DefaultMutableTreeNode(conn_name);
             parent.add(conn_Node);
         }else{
             directory = directory.substring(directory.indexOf("\\")+1 ,directory.length());    
             System.out.println("New Directory in if .... "+directory); 
             if(directory.indexOf("\\")== -1){
                 node= findNode(directory,parent);
                 if(node==null){
                     node = new DefaultMutableTreeNode(directory);
                     parent.add(node);
                 }
                 conn_Node= new DefaultMutableTreeNode(conn_name);
                 node.add(conn_Node);                

             }else{
                 System.out.println("New Directory in else.... "+directory); 
                 node= DrawTree( directory,  node,  conn_name);
             }
         }
     return parent;
         }
    public static void main(String[] args) {
        JFrame frame = new JFrame("Tree");

        Container contentPane = frame.getContentPane();
        contentPane.setLayout(new GridLayout(1, 1));
        contentPane.add(new DICTest(frame));

        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });

        frame.pack();
        frame.setVisible(true);
    }

    private static DefaultMutableTreeNode findNode(String s,DefaultMutableTreeNode root) {
//          DefaultMutableTreeNode root =
//              (DefaultMutableTreeNode)tree.getModel().getRoot();
            Enumeration e = root.breadthFirstEnumeration();
            while(e.hasMoreElements()) {
                DefaultMutableTreeNode node =
                    (DefaultMutableTreeNode)e.nextElement();
                if(node.toString().equals(s)) {
                    return node;
                }
            }
            return null;
        }

}