wordpress仿站主题/sem什么意思

阅读以下说明和Java代码，将应填入(n)处的字句写在答题纸的对应栏内。说明类Queue表示队列，类中的方法如下表所示。类Node表示队列中的元素；类EmptyQueueException 给出了队列操作中的异常处理操作。Java 代码public class TestMain{ // 主类public static void main(String args[]) {Queue q = new Queue();q.enqueue('first!');q.enqueue('second!');q.enqueue('third!');(1) {while(true)System.out.println(q. dequeue());}catch((2)) ( }}}public class Queue { // 队列Node m_FirstNode;public Queue() { m_FirstNode = null; }public boolean isEmpty() {if(m_FirstNode == null) return true;else return false;}public void enqueue(Object newNode) {// 入队操作Node next = m_FirstNode;if(next==null) m_FirstNode = new Node(newNode);else {while(next.getNext() != null) next = next.getNext();next.setNext(new Node(newNode));}}public Object dequeue() (3) {// 出队操作Object node;if (isEmpty())(4); // 队列为空，抛出异常else {node = m_FirstNode.getObject();m_FirstNode = m_FirstNode.getNext();return node;}}}public class Node { // 队列中的元素Object m_Data;Node m_Next;public Node(Object data) { m_Data = data; m_Next = null; }public Node(Object data, Node next) { m_Data = data; m_Next = next; }public void setObject(Object data) { m_Data = data; }public Object getObject0 { return m_Data; }public void setNext(Node next) { m_Next = next; }public Node getNext() { return m_Next; }}public class EmptyQueueException extends (5) { // 异常处理类public EmptyQueueException0 {System.out.println('队列已空 ! ');}}

题型：