dsdecmp/Java/NLinkedListNode.java

public class NLinkedListNode<E> {
	
	private E value;
	private NLinkedListNode<E> previous = null, next = null;
	
	public NLinkedListNode(E value){
		this.setValue(value);
	}
	
	public E getValue(){
		return this.value;
	}
	public void setValue(E value){
		this.value = value;
	}
	
	public NLinkedListNode<E> getNext(){
		return this.next;
	}
	public void setNext(NLinkedListNode<E> next){
		if(this.next != null && this.next.previous == this)
			this.next.previous = null;
		this.next = next;
		if(this.next != null)
			this.next.previous = this;
	}
	public NLinkedListNode<E> getPrevious(){
		return this.previous;
	}
	public void setPrevious(NLinkedListNode<E> previous){
		if(this.previous != null && this.previous.next == this)
			this.previous.next = null;
		this.previous = previous;
		if(this.previous != null)
			this.previous.next = this;
	}
	
	/**
	 * Adds this node after another node
	 * @param node the node this node should be after
	 */
	public void addAfter(NLinkedListNode<E> node){
		assert node != null : "Cannot add a node after null";
		NLinkedListNode<E> next = node.next;
		this.setPrevious(node);
		this.setNext(next);
	}
	/**
	 * Adds this node before another node
	 * @param node the node this node should be before
	 */
	public void addBefore(NLinkedListNode<E> node){
		assert node != null : "Cannot add a node before null";
		NLinkedListNode<E> prev = node.previous;
		this.setNext(node);
		this.setPrevious(prev);
	}
	
	public void remove(){
		if(this.previous != null)
			this.previous.setNext(this.next);
		if(this.next != null)
			this.next.setPrevious(this.previous);
	}

}