Creating a Node Class in Java
So I'm Fairly New to Java and Programming and I Was Wondering How to Create a Node Class? So Far I Have: Public Class Iteminfonode{ Private Iteminfonode Next...
So I'm fairly new to Java and programming and I was wondering how to create a node class?
So far I have:
public class ItemInfoNode{
private ItemInfoNode next;
private ItemInfoNode prev;
private ItemInfo info;
public ItemInfoNode(ItemInfo info, ItemInfoNode next, ItemInfoNode prev){
info = info;
next = next;
prev = prev;
}
public void setInfo(ItemInfo info){
info = info;
}
public void setNext(ItemInfoNode node){
next = node;
}
public void setPrev(ItemInfoNode node){
prev = node;
}
public ItemInfo getInfo(){
return info;
}
public ItemInfoNode getNext(){
return next;
}
public ItemInfoNode getPrev(){
return prev;
}
}
Pretty much the question asked for those methods so I put those down but, the next question asks me to refer to the head and tail of ItemInfoNode nodes. Just a bit confused here. Thanks
EDIT: Thanks for the help guys! I'm trying to create an "InsertInfo" method that puts information like the name, price, tag number, etc. Into one node. How do I go about creating this method?
So far I got this.. I have an Iteminfo constructor in a different class that has all of these but, I'm not sure how to use that/if I am even supposed to do..
public void InsertInfo(String name, String rfdnumber, double price, String original_position){
head = new ItemInfoNode (Iteminfo, head);
}
1 Answer
Welcome to Java! This Nodes are like a blocks, they must be assembled to do amazing things! In this particular case, your nodes can represent a list, a linked list, You can see an example here:
public class ItemLinkedList {
private ItemInfoNode head;
private ItemInfoNode tail;
private int size = 0;
public int getSize() {
return size;
}
public void addBack(ItemInfo info) {
size++;
if (head == null) {
head = new ItemInfoNode(info, null, null);
tail = head;
} else {
ItemInfoNode node = new ItemInfoNode(info, null, tail);
this.tail.next =node;
this.tail = node;
}
}
public void addFront(ItemInfo info) {
size++;
if (head == null) {
head = new ItemInfoNode(info, null, null);
tail = head;
} else {
ItemInfoNode node = new ItemInfoNode(info, head, null);
this.head.prev = node;
this.head = node;
}
}
public ItemInfo removeBack() {
ItemInfo result = null;
if (head != null) {
size--;
result = tail.info;
if (tail.prev != null) {
tail.prev.next = null;
tail = tail.prev;
} else {
head = null;
tail = null;
}
}
return result;
}
public ItemInfo removeFront() {
ItemInfo result = null;
if (head != null) {
size--;
result = head.info;
if (head.next != null) {
head.next.prev = null;
head = head.next;
} else {
head = null;
tail = null;
}
}
return result;
}
public class ItemInfoNode {
private ItemInfoNode next;
private ItemInfoNode prev;
private ItemInfo info;
public ItemInfoNode(ItemInfo info, ItemInfoNode next, ItemInfoNode prev) {
this.info = info;
this.next = next;
this.prev = prev;
}
public void setInfo(ItemInfo info) {
this.info = info;
}
public void setNext(ItemInfoNode node) {
next = node;
}
public void setPrev(ItemInfoNode node) {
prev = node;
}
public ItemInfo getInfo() {
return info;
}
public ItemInfoNode getNext() {
return next;
}
public ItemInfoNode getPrev() {
return prev;
}
}
}
EDIT:
Declare ItemInfo as this:
public class ItemInfo {
private String name;
private String rfdNumber;
private double price;
private String originalPosition;
public ItemInfo(){
}
public ItemInfo(String name, String rfdNumber, double price, String originalPosition) {
this.name = name;
this.rfdNumber = rfdNumber;
this.price = price;
this.originalPosition = originalPosition;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getRfdNumber() {
return rfdNumber;
}
public void setRfdNumber(String rfdNumber) {
this.rfdNumber = rfdNumber;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
public String getOriginalPosition() {
return originalPosition;
}
public void setOriginalPosition(String originalPosition) {
this.originalPosition = originalPosition;
}
}
Then, You can use your nodes inside the linked list like this:
public static void main(String[] args) {
ItemLinkedList list = new ItemLinkedList();
for (int i = 1; i <= 10; i++) {
list.addBack(new ItemInfo("name-"+i, "rfd"+i, i, String.valueOf(i)));
}
while (list.size() > 0){
System.out.println(list.removeFront().getName());
}
}
Sarah Jenkins is a veteran tech journalist with over 12 years of experience covering artificial intelligence, mobile innovations, and digital ethics. Her insights have appeared in leading technology publications worldwide.
