In java. Write a class called GenDoubleLinkedList which is a generic double linked list. This link list is similar to the single linked list that was shown in class except that each node in addition to having data and nextLink (which was originally called link) now has prevLink. The class GenDoubleLinkedList needs to have the following: Internal class ListNode which hasInstance Variables data of type T nextLink of type ListNode prevLink of type ListNode Constructors Default Parameterized Instance Variables head of type ListNode which always points to the beginning of the linked list current of type ListNode which moves around pointing to one of the nodes Constructor A default constructor that initializes head to an empty ListNode and sets current to point at the head. Methods goToNext – This moves the current node forward in the list by one node. It doesn’t move forward if that node is null goToPrev – This moves the current node backwards in the list by one node. It doesn’t move backwards if that node is null. getDataAtCurrent – returns the data at the current node as long as the current isn’t null setDataAtCurrent – takes in a parameter and sets the data at the current node to that value as long as current is not null insertNodeAfterCurrent – creates a new node based on data that is passed in by a parameter and puts that node after the current position deleteCurrentNode – removes the current node from the list by resetting the links showList – prints out the contents of the list line-by-line inList – returns a true or false value based on whether or not the data passed in via a parameter is in the list Solution package com.quad.generic; public class GenDoubleLinkedList { private ListNode head; private ListNode tail; private int size; public int getSize() { return size; } /** * */ public GenDoubleLinkedList() { this.head = null; this.size = 0; } @SuppressWarnings(\"hiding\") class ListNode{ private T data; private ListNode nextLink; private ListNode prevLink; /** * */ public ListNode() { nextLink=null; prevLink=null; data=null; } /** * @param data * @param nextLink * @param prevLink */ public ListNode(T data, ListNode nextLink, ListNode prevLink) { super(); this.data = data; this.nextLink = nextLink; this.prevLink = prevLink; } public T getData() { return data; } public void setData(T data) { this.data = data; } public ListNode getNextLink() { return nextLink; } public void setNextLink(ListNode nextLink) { this.nextLink = nextLink; } public ListNode getPrevLink() { return prevLink; } public void setPrevLink(ListNode prevLink) { this.prevLink = prevLink; } } public void goToNext(){ ListNode temp = head; while(temp != null){ temp = temp.getNextLink(); } } public void goToPrev() { ListNode temporary = tail; while(temporary != null){ temporary = temporary.getPrevLink(); } } public T getDataAtCurrent (int index) { if (index < 0 || index >= size) { throw new IndexOutOfBoundsException(); } else { ListNode current = head; for (int i = 0; i < index; i.

1. In java.
Write a class called GenDoubleLinkedList which is a generic double linked list. This link list is
similar to the single linked list that was shown in class except that each node in addition to
having data and nextLink (which was originally called link) now has prevLink.
The class GenDoubleLinkedList needs to have the following:
Internal class ListNode which hasInstance Variables
data of type T
nextLink of type ListNode
prevLink of type ListNode
Constructors
Default
Parameterized
Instance Variables
head of type ListNode which always points to the beginning of the linked list
current of type ListNode which moves around pointing to one of the nodes
Constructor
A default constructor that initializes head to an empty ListNode and sets current to point at the
head.
Methods
goToNext – This moves the current node forward in the list by one node. It doesn’t move
forward if that node is null
goToPrev – This moves the current node backwards in the list by one node. It doesn’t move
backwards if that node is null.
getDataAtCurrent – returns the data at the current node as long as the current isn’t null
setDataAtCurrent – takes in a parameter and sets the data at the current node to that value as long
as current is not null
insertNodeAfterCurrent – creates a new node based on data that is passed in by a parameter and
puts that node after the current position
deleteCurrentNode – removes the current node from the list by resetting the links
showList – prints out the contents of the list line-by-line
inList – returns a true or false value based on whether or not the data passed in via a parameter is
in the list
Solution

2. package com.quad.generic;
public class GenDoubleLinkedList {
private ListNode head;
private ListNode tail;
private int size;
public int getSize() {
return size;
}
/**
*
*/
public GenDoubleLinkedList() {
this.head = null;
this.size = 0;
}
@SuppressWarnings("hiding")
class ListNode{
private T data;
private ListNode nextLink;
private ListNode prevLink;
/**
*
*/
public ListNode() {
nextLink=null;
prevLink=null;
data=null;
}
/**
* @param data
* @param nextLink
* @param prevLink
*/

3. public ListNode(T data, ListNode nextLink,
ListNode prevLink) {
super();
this.data = data;
this.nextLink = nextLink;
this.prevLink = prevLink;
}
public T getData() {
return data;
}
public void setData(T data) {
this.data = data;
}
public ListNode getNextLink() {
return nextLink;
}
public void setNextLink(ListNode nextLink) {
this.nextLink = nextLink;
}
public ListNode getPrevLink() {
return prevLink;
}
public void setPrevLink(ListNode prevLink) {
this.prevLink = prevLink;
}
}
public void goToNext(){
ListNode temp = head;
while(temp != null){
temp = temp.getNextLink();
}

4. }
public void goToPrev() {
ListNode temporary = tail;
while(temporary != null){
temporary = temporary.getPrevLink();
}
}
public T getDataAtCurrent (int index) {
if (index < 0 || index >= size) {
throw new IndexOutOfBoundsException();
} else {
ListNode current = head;
for (int i = 0; i < index; i++) {
current = current.nextLink;
}
return current.data;
}
}
public ListNode deleteCurrentNode(){
ListNode temp = head;
if(head.nextLink == null){
tail = null;
}
else{
head.nextLink.prevLink = null;
head = head.nextLink;
}
return temp;
}
}