public class SJBLinkedList{
private Node first;
private Node last;
private int size;
public int size(){
return size;
}
public boolean isEmpty(){
return size == 0;
}
public void add(Object obj){
Node node = new Node();
if(first == null){
node.obj = obj;
node.previous = null;
node.next = null;
first = node;
last = node;
}else{
node.obj = obj;
node.previous = last;
node.next = null;
last.next = node;
last = node;
}
size++;
}
private Node getNode(int index){
if(index < 0 || index >size ){
try {
throw new Exception();
} catch (Exception e) {
e.printStackTrace();
System.exit(0);
}
}
Node temp = null;
if(first != null){
temp = first;
for (int i=0;i<index;i++){
temp = temp.next;
}
}
return temp;
}
public Object get(int index){
return getNode(index).obj;
}
public void remove(int index){
if(index < 0 || index >size ){
try {
throw new Exception();
} catch (Exception e) {
e.printStackTrace();
System.exit(0);
}
}
Node currentNode = getNode(index);
Node upNode = currentNode.previous;
Node downNode = currentNode.next;
upNode.next = downNode;
downNode.previous = upNode;
size--;
}
private class Node{
private Node previous;
private Object obj;
private Node next;
public Node(Node previous,Node next,Object obj){
this.previous = previous;
this.obj = obj;
this.next = next;
}
public Node(){
}
public Node getPrevious() {
return previous;
}
public void setPrevious(Node previous) {
this.previous = previous;
}
public Object getObj() {
return obj;
}
public void setObj(Object obj) {
this.obj = obj;
}
public Node getNext() {
return next;
}
public void setNext(Node next) {
this.next = next;
}
}
public static void main(String[] args){
SJBLinkedList list = new SJBLinkedList();
list.add("123");
list.add("234");
list.add("345");
for(int i=0;i<3;i++){
System.out.println(list.get(i));
}
//System.out.println(list.get(5));
}
}