java在双链表中删除头

Question

我叫马里奥，我有一个问题。如果我有1->；2->；3我想去掉我设置的头。头部=移除的头部。getNextNode（）和之后，我只将上一个节点设置为null

public String removeHead()
 {
     Node removedHead = this.head;    // variable for removedHead
     if(removedHead ==null)
     {
         return null;
     }
     this.head=removedHead.getNextNode(); // get next node to head
     if( this.head != null)
     {
         this.head.setPreviousNode(null); // setting the previous node ==null
     }
     if(removedHead == this.tail)
     {
         this.removeTail();
     }
     return removedHead.data;
 }