링크 큐 의 자바 구현

public class LinkQueue {
    //        Node，Node          。
    private class Node {
        //        
        private T data;
        //          
        private Node next;

        //        
        public Node() {
        }

        //            
        public Node(T data, Node next) {
            this.data = data;
            this.next = next;
        }
    }

    //           
    private Node front;
    //           
    private Node rear;
    //               
    private int size;

    //       
    public LinkQueue() {
        //     ，front rear  null
        front = null;
        rear = null;
    }

    //              ，          
    public LinkQueue(T element) {
        front = new Node(element, null);
        //       ，front、rear      
        rear = front;
        size++;
    }

    //         
    public int length() {
        return size;
    }

    //         
    public void add(T element) {
        //             
        if (front == null) {
            front = new Node(element, null);
            //       ，front、rear      
            rear = front;
        } else {
            //      
            Node newNode = new Node(element, null);
            //      next       
            rear.next = newNode;
            //            
            rear = newNode;
        }
        size++;
    }

    //     front    
    public T remove() {
        Node oldFront = front;
        front = front.next;
        oldFront.next = null;
        size--;
        return oldFront.data;
    }

    //              
    public T element() {
        return rear.data;
    }

    //             
    public boolean empty() {
        return size == 0;
    }

    //      
    public void clear() {
        //  front、rear      null
        front = null;
        rear = null;
        size = 0;
    }

    public String toString() {
        //          
        if (empty()) {
            return "[]";
        } else {
            StringBuilder sb = new StringBuilder("[");
            for (Node current = front; current != null; current = current.next) {
                sb.append(current.data.toString() + ", ");
            }
            int len = sb.length();
            return sb.delete(len - 2, len).append("]").toString();
        }
    }
}