Generic tree implementation in Java

Question

Is anyone aware of a generic tree (nodes may have multiple children) implementation for Java? It should come from a well trusted source and must be fully tested.

It just doesn't seem right implementing it myself. Almost reminds me of my university years when we were supposed to write all our collections ourselves.

EDIT: Found this project on java.net, might be worth looking into.

Answer 1

Here it comes:

abstract class TreeNode implements Iterable<TreeNode> {    private Set<TreeNode> children;    public TreeNode() {     children = new HashSet<TreeNode>();   }    public boolean addChild(TreeNode n) {     return children.add(n);   }    public boolean removeChild(TreeNode n) {     return children.remove(n);   }    public Iterator<TreeNode> iterator() {     return children.iterator();   } } 

I am well trusted, but haven't tested the implementation.

Answer 2

There isn't a Tree class in the Collections libraries. However, there is one in the Swing Frameworks. DefaultTreeModel

I have used this in the past and it works well. It does pull in additional classes into your application though which may or may not be desirable.

You can also simulate a Tree using another collection and storing collections in it. Eg. List of Lists.