How to Stop JTree from collapsing after removing a node from the tree

Question

I'm making a JTree and I have a button that removes a node from the tree. Everytime I removde the node with the button, the Tree automatically collapse. I've read that it's becasue I'm using .reload(). I've also read some SO answers that suggested using .nodeChanged(node), which I've tried but when I use that, I believe the model is getting updated, but the tree doesn't reload accordingly in the GUI. How can I get the tree not to collapse?

Here's a simple SSCCE with the default JTree and a button to remove a node

import java.awt.BorderLayout;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;

public class StopTreeCollapse extends JApplet {

    JTree tree = new JTree();
    JButton jbtRemove = new JButton("Remove Node");

    public StopTreeCollapse(){

        add(new JScrollPane(tree), BorderLayout.CENTER);
        add(jbtRemove, BorderLayout.SOUTH);

        jbtRemove.addActionListener(new ActionListener(){
            @Override
            public void actionPerformed(ActionEvent e) {
                TreePath[] paths = tree.getSelectionPaths();

                if (paths == null) {
                    JOptionPane.showMessageDialog(null,
                            "No node in the tree is selected");
                    return;
                }
                DefaultMutableTreeNode node = null; 
                for (TreePath path : paths) {
                    node = (DefaultMutableTreeNode) (path.getLastPathComponent());
                    if (node.isRoot()) {
                        JOptionPane.showMessageDialog(null, "Cannot remove the root");
                    } else {
                        node.removeFromParent();
                    }
                }
                ((DefaultTreeModel) tree.getModel()).reload();
            }
        });
    }
}

Answer 1

reload() essentially says "the whole tree may have changed, forget anything you previously knew about it and start again".

Instead of using node.removeFromParent() and then reloading the whole tree, try

((DefaultTreeModel) tree.getModel()).removeNodeFromParent(node);

This will fire a more specific modification event telling listeners that that particular node has been removed but the rest of the tree is unchanged, so you no longer require the reload() call.