Question { 2532 }

How to add and remove nodes in Jtree?

Answer

You have a couple of choices:

Update the model directly:

DefaultTreeModel model = (DefaultTreeModel) tree.getModel();
DefaultMutableTreeNode root = (DefaultMutableTreeNode) model.getRoot();
model.insertNodeInto(new DefaultMutableTreeNode("another_child"), root, root.getChildCount());
Update the tree nodes and then notify the model:

DefaultTreeModel model = (DefaultTreeModel)tree.getModel();
DefaultMutableTreeNode root = (DefaultMutableTreeNode)model.getRoot();
root.add(new DefaultMutableTreeNode("another_child"));
model.reload(root);
The same applies for removing nodes.

The DefaultTreeModel has a removeNodeFromParent(...) which will update the model directly.

Or you can use the remove(...) method of the DefaultMutableTreeNode class. In which case you would need to do the reload().