Java隊(duì)列是一種基于先進(jìn)先出（FIFO）原則的數(shù)據(jù)結(jié)構(gòu)，其中新的元素在隊(duì)列的尾部添加，而舊的元素則從隊(duì)列的頭部移除。隊(duì)列由兩個(gè)指針來(lái)操作：頭指針和尾指針。

public class Queue {
private Node head;
private Node tail;
public Queue() {
head = null;
tail = null;
}
public void enqueue(Object data) {
Node newNode = new Node(data);
if (tail == null) {
head = newNode;
tail = newNode;
} else {
tail.next = newNode;
tail = newNode;
}
}
public Object dequeue() {
if (head == null) {
return null;
} else {
Object data = head.data;
head = head.next;
if (head == null) {
tail = null;
}
return data;
}
}
private class Node {
Object data;
Node next;
Node(Object data) {
this.data = data;
this.next = null;
}
}
}

上面的代碼定義了一個(gè)名叫Queue的類，其中頭指針（head）指向隊(duì)列的頭部，尾指針（tail）指向隊(duì)列的尾部。enqueue方法用于向隊(duì)列中添加元素，它將新元素添加到尾指針?biāo)傅奈恢蒙稀equeue方法用于從隊(duì)列中移除元素，它將頭指針?biāo)傅脑匾瞥㈩^指針指向下一個(gè)元素。