Basic Linked list and a few tests. Just a simple assignment for CS220.

NumberNode.java

public class NumberNode {
	private NumberNode next;
	private int num;
	
	public NumberNode(int num, NumberNode next) {
		this.num = num;
		this.next = next;
	}
	
	public NumberNode(int num) {
		this(num, null);
	}
	
	public NumberNode() {
		this(0, null);
	}

	public NumberNode getNext() {
		return next;
	}

	public void setNext(NumberNode next) {
		this.next = next;
	}

	public int getNum() {
		return num;
	}

	public void setNum(int num) {
		this.num = num;
	}
	
	public static void printList(NumberNode head) {
		System.out.print("{");
		
		NumberNode pos = head;
		while(pos != null) {
			
			if(head != pos) System.out.print(",");
			System.out.print(pos.getNum());
			
			pos = pos.getNext();
		}
		
		System.out.println("}");
	}
	
	public void insertAfter(int number) {
		this.setNext(new NumberNode(number, this.getNext()));
	}
	
	public void removeAfter() {
		NumberNode temp = this.getNext();
		this.setNext(temp.getNext());
		temp.setNext(null);
	}
	
	public int get(int index) throws Exception {
		
		NumberNode pos = this;
		for(int i=0; i<index; i++) {
			pos = pos.getNext();
			
			if(pos == null) throw new Exception("Index not in list.");
		}
		
		return pos.getNum();
	}
	
	public int length() {
		NumberNode pos = this;
		int i = 0;
		while(pos != null) {
			i++;
			pos = pos.getNext();
		}
		
		return i;
	}
	
	public static void main(String args[]) {
		final NumberNode head = new NumberNode(1, new NumberNode(2, new NumberNode(3)));
		
		System.out.print("Original list: ");
		printList(head);
		
		System.out.println("Adding 4 after the head");
		head.insertAfter(4);
		
		System.out.print("New list: ");
		printList(head);
		
		System.out.println("Removing the 4 I just added");
		head.removeAfter();
		
		System.out.print("Updated list: ");
		printList(head);
		
		try {
			System.out.println("Getting number at index 2: " + head.get(2));
		} catch(Exception e) {
			System.out.println("There is not an index 2");
		}
		
		System.out.println("The length of this linked list is: " + head.length());
		
	}
	
}