الفرق بين الكودين؟

Object P;
if(isEmpty())
throw new RuntimeException("The queue is Empty");
else{

P=front.getInfo();
front=front.getNext();
if(front==null)
rear=null;

}
return P;
}

public Object dequeue(){

Object P;
if(isEmpty())
throw new RuntimeException("The queue is Empty");
else{
if(rear==front){

P=rear.getInfo();
front=null;
rear=null;
}
else{

Snode current=front;
Snode prev=front;
P=rear.getInfo();
while(current!=rear){
prev=current;
current=current.getNext();
}
prev.setNext(null);
rear=prev;
}
}
return P;
}

public Object dequeue_End(){