How to implement a tree data-structure in Java?

Question

Is there any standard Java library class to represent a tree in Java?

Specifically I need to represent the following:

• The sub-tree at any node can have

Answer 1

Yet another tree structure:

public class TreeNode implements Iterable> {

    T data;
    TreeNode parent;
    List> children;

    public TreeNode(T data) {
        this.data = data;
        this.children = new LinkedList>();
    }

    public TreeNode addChild(T child) {
        TreeNode childNode = new TreeNode(child);
        childNode.parent = this;
        this.children.add(childNode);
        return childNode;
    }

    // other features ...

}

Sample usage:

TreeNode root = new TreeNode("root");
{
    TreeNode node0 = root.addChild("node0");
    TreeNode node1 = root.addChild("node1");
    TreeNode node2 = root.addChild("node2");
    {
        TreeNode node20 = node2.addChild(null);
        TreeNode node21 = node2.addChild("node21");
        {
            TreeNode node210 = node20.addChild("node210");
        }
    }
}

BONUS
See fully-fledged tree with:

• iterator
• searching
• Java/C#

https://github.com/gt4dev/yet-another-tree-structure