命令模式的运用.doc

实验四 命令模式的运用一、实验目的：命令模式将“请求”封装成对象，以便使用不同的请求、队列或者日志来参数化其他对象，命令模式也支持可撤销的操作。在熟悉命令模式相关理论知识的基础上，使用命令模式实现图片处理程序。二、实验要求：使用命令模式实现图片处理程序，要求如下：1. 图片处理程序要有3张图片。2. 每张图片至少有3种操作。3. 实现类似遥控器的菜单，动态的选择对图片进行的处理。4. 要有“撤消操作”，撤消操作要可以撤销至最后一步。1、 设计并绘制该程序的类图；2、 依照设计的类图使用Java语言编写代码，并实现该程序；3、 除了核心的模式相关类实现外，提供测试环境，按照难度高低，分别是：a) 控制台程序，Client硬编码初始化模式和测试环境，运行结果文本输出；b) 控制台程序，Client初始化测试环境，并根据用户输入运算，运行结果文本输出；c) 设计并实现用户UI，Client初始化测试环境，并根据用户在UI控件上的输入运算，运行结果文本输出；三、实验内容：类图代码package Picture;public interface Command public void execute();public void undo();package Picture;public class NoCommand implements Command public void execute() public void undo() package Picture;public class Picture public static final int enlarge=1; /放大图片; public static final int rotating=2;/旋转图片; public static final int ensmall=3;/ 缩小图片; public static final int OFF= 0;/无操作; int way; String location;public Picture(String location) this.location = location;way=OFF; public void enlarge() way = enlarge;System.out.println(location + 已放大); public void rotating() way= rotating;System.out.println(location + 已旋转180);public void ensmall() way = ensmall;System.out.println(location + 已缩小); public void OFF() way= OFF;System.out.println(location + 无操作);public int getWay() return way;package Picture;public class PictureenlargeCommand implements Command Picture p;int prevWay; public PictureenlargeCommand(Picture p) this.p=p; public void execute() prevWay = p.getWay();p.enlarge(); public void undo() if (prevWay = p.enlarge) p.enlarge(); else if (prevWay =p.ensmall) p.ensmall(); else if (prevWay = p.rotating) p.rotating(); else if (prevWay = p.OFF) p.OFF();package Picture;public class PictureensmallCommand implements Command Picture p;int prevWay; public PictureensmallCommand(Picture p) this.p=p; public void execute() prevWay = p.getWay();p.ensmall(); public void undo() if (prevWay = p.enlarge) p.enlarge(); else if (prevWay =p.ensmall) p.ensmall(); else if (prevWay = p.rotating) p.rotating(); else if (prevWay = p.OFF) p.OFF();package Picture;public class PictureroatingCommand implements Command Picture p;int prevWay; public PictureroatingCommand(Picture p) this.p=p; public void execute() prevWay = p.getWay();p.rotating(); public void undo() if (prevWay = p.enlarge) p.enlarge(); else if (prevWay =p.ensmall) p.ensmall(); else if (prevWay = p.rotating) p.rotating(); else if (prevWay = p.OFF) p.OFF();package Picture;import java.util.LinkedList;import java.util.List;import java.util.*;/ This is the invoker/public class RemoteControlWithUndo Command enlargeCommands;Command ensmallCommands;Command rotatingCommands;List undoCommand;public RemoteControlWithUndo() enlargeCommands = new Command3;ensmallCommands = new Command3;rotatingCommands = new Command3;Command noCommand = new NoCommand();for(int i=0;i3;i+) enlargeCommandsi = noCommand;ensmallCommandsi = noCommand;rotatingCommandsi = noCommand;undoCommand=new LinkedList(); public void setCommand(int slot, Command enlargeCommand, Command ensmallCommand,Command rotatingCommand) enlargeCommandsslot = enlargeCommand;ensmallCommandsslot = ensmallCommand;rotatingCommandsslot = rotatingCommand; public void largeButtonWasPushed(int slot) enlargeCommandsslot.execute();undoCommand.add(enlargeCommandsslot); public void smallButtonWasPushed(int slot) ensmallCommandsslot.execute();undoCommand.add(ensmallCommandsslot);public void rotatingButtonWasPushed(int slot) rotatingCommandsslot.execute();undoCommand.add(rotatingCommandsslot); public void undoButtonWasPushed() undoCommand.remove(undoCommand.size()-1).undo();测试代码package Picture;public class RemoteLoader public static void main(String args) RemoteControlWithUndo remoteControl = new RemoteControlWithUndo();Picture p=new Picture3;PictureenlargeCommand enlarge=new PictureenlargeCommand3;PictureensmallCommand ensmall=new PictureensmallCommand3;PictureroatingCommand roating =new PictureroatingCommand3;for(int i=0;i3;i+)pi=new Picture(图+(i+1); enlargei = new PictureenlargeCommand(pi); ensmalli = new PictureensmallCommand(pi);roatingi = new PictureroatingCommand(pi);remoteControl.setCommand(i, enlargei, ensmalli, roatingi);System.out.println(图片处理);for(int i=0;i3;i+)remoteControl.largeButtonWasPushed(i);remoteControl.smallButtonWasPushe