Preciso implementar na classe List (implementação simplesmente encadea

Preciso implementar na classe List (implementação simplesmente encadeada) o seguinte método: public void ordenacaoLista()

//Ultilizar o método Bubble Sort

public void ordenacaoLista()

//classe List

public class List {

 private Node firstNode;

 private Node lastNode;

 private String name;

 public List() {
 this("list");
 }

 public List(String listName) {
 name = listName;
 firstNode = lastNode = null;
 }

 public Node getFirst() {
 return firstNode;
 }

 public Node getLast() {
 return lastNode;
 }

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

 public void insertAtFront(Object insertItem) {
 Node n = new Node(insertItem);
 if (isEmpty())
 firstNode = lastNode = n;

 else {
 firstNode.setPrevious(n);
 n.setNext(firstNode);
 firstNode = n;
 }
 }

 public void insertAtBack(Object insertItem) {
 Node n = new Node(insertItem);
 if (isEmpty())
 firstNode = lastNode = n;

 else {
 lastNode.setNext(n);
 n.setPrevious(lastNode);
 lastNode = n;
 }
 }

 public Object removeFromFront() throws UnderflowException {
 if (isEmpty())
 throw new UnderflowException();

 Object removedItem = firstNode.getData();

 if (firstNode == lastNode)
 firstNode = lastNode = null;
 else {
 firstNode = firstNode.getNext();
 firstNode.setPrevious(null);
 }

 return removedItem;

 }

 public Object removeFromBack() throws UnderflowException {
 if (isEmpty())
 throw new UnderflowException();

 Object removedItem = lastNode.getData();

 if (firstNode == lastNode)
 firstNode = lastNode = null;

 else {
 Node penultimo = lastNode.getPrevious();
 lastNode = penultimo;
 lastNode.setNext(null);
 }

 return removedItem;