快速业务通道

演化架构和紧急设计: 使用 DSL - 编程入门网

作者 佚名技术 来源 NET编程 浏览 发布时间 2012-06-15
uilder>();   private List<Commands> commands = new ArrayList<Commands>();   public States(String name, StateMachineBuilder builder) {    super(name, builder);    content = new State(name);   }   State getState() {    return content;   }   public States actions(Commands... identifiers) {    builder.definingState(this);    commands.addAll(Arrays.asList(identifiers));    return this;   }   public TransitionBuilder transition(Events identifier) {    builder.definingState(this);    return new TransitionBuilder(this, identifier);   }   void addTransition(TransitionBuilder arg) {    transitions.add(arg);   }   void produce() {    for (Commands c : commands)     content.addAction(c.getCommand());    for (TransitionBuilder t : transitions)     t.produce();   }   }

演化架构和紧急设计: 使用 DSL(3)

时间:2011-08-18 IBM Neal Ford

清单 1和 清单 2仅做参考。需要解决的问题是如何表示状态机的配置。这种表示是安装暗格的一种惯 用模式。清单 3 展示了状态机基于 Java 的配置:

清单 3. 一个配置选择:Java 代码

Event doorClosed = new Event("doorClosed", "D1CL");   Event drawerOpened = new Event("drawerOpened", "D2OP");   Event lightOn = new Event("lightOn", "L1ON");   Event doorOpened = new Event("doorOpened", "D1OP");   Event panelClosed = new Event("panelClosed", "PNCL");   Command unlockPanelCmd = new Command("unlockPanel", "PNUL");   Command lockPanelCmd = new Command("lockPanel", "PNLK");   Command lockDoorCmd = new Command("lockDoor", "D1LK");   Command unlockDoorCmd = new Command("unlockDoor", "D1UL");   State idle = new State("idle");   State activeState = new State("active");   State waitingForLightState = new State("waitingForLight");   State waitingForDrawerState = new State("waitingForDrawer");   State unlockedPanelState = new State("unlockedPanel");   StateMachine machine = new StateMachine(idle);   idle.addTransition(doorClosed, activeState);   idle.addAction(unlockDoorCmd);   idle.addAction(lockPanelCmd);   activeState.addTransition(drawerOpened, waitingForLightState);   activeState.addTransition(lightOn, waitingForDrawerState);   waitingForLightState.addTransition(lightOn, unlockedPanelState);   waitingForDrawerState.addTransition(drawerOpened, unlockedPanelState);   unlockedPanelState.addAction(unlockPanelCmd);   unlockedPanelState.addAction(lockDoorCmd);   unlockedPanelState.addTransition(panelClosed, idle);   machine.addResetEvents(doorOpened);

清单 3显示了使用 Java 进行状态机配置的几个问题。首先,阅读这些 Java 代码并不能明确知道这 就是状态机配置,和多数 Java API 一样,这只是一堆没有差别的代码。第二,冗长且重

凌众科技专业提供服务器租用、服务器托管、企业邮局、虚拟主机等服务,公司网站:http://www.lingzhong.cn 为了给广大客户了解更多的技术信息,本技术文章收集来源于网络,凌众科技尊重文章作者的版权,如果有涉及你的版权有必要删除你的文章,请和我们联系。以上信息与文章正文是不可分割的一部分,如果您要转载本文章,请保留以上信息,谢谢!

分享到: 更多

Copyright ©1999-2011 厦门凌众科技有限公司 厦门优通互联科技开发有限公司 All rights reserved

地址(ADD):厦门软件园二期望海路63号701E(东南融通旁) 邮编(ZIP):361008

电话:0592-5908028 传真:0592-5908039 咨询信箱:web@lingzhong.cn 咨询OICQ:173723134

《中华人民共和国增值电信业务经营许可证》闽B2-20100024  ICP备案:闽ICP备05037997号