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阅读以下说明,回答问题1至问题5。
[说明]
VLAN(Virtual Local Area Network)即“虚拟局域网”,是为解决以太网的广播问题和安全问题而提出的一种协议。有一个VLAN拓扑如图11-2所示,其端口与VLAN的关系如表11-2所示。

请根据图11-2说出,VLAN是基于什么划分的?

A.shangxueba.cn/images/ct_crpnmxm_crpnmxfuzacz5_00155(20093).jpg'

【参考答案】

基于端口的VLAN划分。VLAN(Virtual Local Area Network)又称虚拟局域网是指在交换局域网的......

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阅读以下说明以及Java程序。【说明】传输门是传输系统中的重要装置。传输门具有Open(打开)、Closed(关闭)、Opening (正在打开)、StayOpen(保持打开)和Closing(正在关闭)五种状态。触发状态的转换事件有click、complete和timeout三种。事件与其相应的状态转换如下图所示。下面的Java代码1与Java代码2分别用两种不同的设计思路对传输门进行状态模拟,请填补代码中的空缺。【Java代码1】public class Door {public static final int CLOSED = 1; public static final int PENING = 2;public static final int PEN = 3; public static final int CLOSING = 4;public static final int STAYOPEN = 5; private int state = CLOSED; 定义状态变量,用不同的整数表示不同状态private void setState(int state){ this.state = state;} 设置传输门当前状态public void getState() { 此处代码省略,本方法输出状态字符串, 例如,当前状态为CLOSED时,输出字符串为'CLOSED'}public void click() { 发生click事件时进行状态转换if ((1);) setState(OPENING);else if ((2);) setState{CLOSING);else if ((3);) setState(STAYOPEN);} 发生timeout事件时进行状态转换public void timeout() { if (state == OPEN) setState(CLOSING);}public void complete() { 发生complete事件时进行状态转换if (state == OPENING) setState(OPEN);else if (state == CLOSING) setState(CLOSED);}public static void main(String [] args){Door aDoor = new Door();aDoor.getState();aDoor.click();aDoor.getState();aDoor.complete();aDoor.getState();aDoor.click();aDoor.getState();aDoor.click();aDoor.getState();return;}}【Java代码2】public class Door {public final DoorState CLOSED = new DoorClosed(this);public final DoorState PENING = new DoorOpening(this);public final DoorState PEN = new DoorOpen(this);public final DoorState CLOSING = new DoorClosing(this);public final DoorState STAYOPEN = new DoorStayOpen(this);private DoorState state = CLOSED; 设置传输门当前状态public void setState(DoorState state) { this.state=state;}public void getState(){ 根据当前状态输出对应的状态字符串System.out.println(state.getClass().getName());}public void click(){(4);} 发生click事件时进行状态转换public void timeout(){(5);} 发生timeout事件时进行状态转换public void complete(){(6);) 发生complete事件时进行状态转换public static void main(String[]args){Door aDoor = new Door();aDoor.getState();aDoor.click();aDoor.getState();aDoor.complete();aDoor.getState();aDoor.timeout();aDoor.getState();return;}}public abstract class DoorState { 定义所有状态类的基类protected Door door ;public DoorState(Door doer) { this.door = door;}public void click() {}public void complete() {}