BinaryTreeNode.java

package collection.concrete;

public class BinaryTreeNode<E extends Comparable<E>> {

	private E data;
	private BinaryTreeNode left;
	private BinaryTreeNode right;
	private int size;
	private ArrayList<E> myList;

	public BinaryTreeNode() {
		this.data = null;
		this.left = null;
		this.right = null;
	}

	public BinaryTreeNode(E data) {
		this.data = data;
		this.left = null;
		this.right = null;
	}

	public boolean isEmpty() {
		return data == null;
	}

	public int size() {
		return size;
	}

	public BinaryTreeNode<E> insert(E o) {
		BinaryTreeNode<E> res;
		if (isEmpty()) {
			data = o;
			size++;
			return this;
		} else {
			BinaryTreeNode<E> p = this;
			res = new BinaryTreeNode<E>(o);
			while (true) {
				if (res.getData().compareTo(p.getData()) < 0) {
					if (p.left == null) {
						p.setLeft(res);
						break;
					}
					p = p.left;
				} else if (res.getData().compareTo(p.getData()) > 0) {
					if (p.right == null) {
						p.setRight(res);
						break;
					}
					p = p.right;
				} else {
					return null;
				}
			}
			size++;
		}
		return res;
	}

	public ArrayList<E> preOrderTraversal(BinaryTreeNode<E> node) {

		if (node != null) {
			preOrderTraversal(node.left);
			myList.add(node.data);
			preOrderTraversal(node.right);
		}
		return myList;
	}

	@Override
	public String toString() {
		myList = new ArrayList<E>();
		return preOrderTraversal(this).toString();
	}

	public E getData() {
		return data;
	}

	public void setData(E data) {
		this.data = data;
	}

	public BinaryTreeNode getLeft() {
		return left;
	}

	public void setLeft(BinaryTreeNode left) {
		this.left = left;
	}

	public BinaryTreeNode getRight() {
		return right;
	}

	public void setRight(BinaryTreeNode right) {
		this.right = right;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((data == null) ? 0 : data.hashCode());
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		BinaryTreeNode other = (BinaryTreeNode) obj;
		if (data == null) {
			if (other.data != null)
				return false;
		} else if (!data.equals(other.data))
			return false;
		return true;
	}

}