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模式设计应用之状态

预计阅读时间: 9 分钟

当我们业务流程中有很多状态的时候,我们可以采用状态模式。

例如我们有一个业务需要新增-审核-发布,那么这里就有三种状态(新增状态、审核状态、发布状态)。

每种状态里面可能会有不同的分类状态,例如审核-审核通过、审核不通过等。

我按照这种情形设计了以下类图:

模式设计应用之状态

新增状态、审核状态、发布状态、Context分别实现State接口,把Context作为上下文处理State,当业务进行到不同状态时,setState不同状态,调用处理方法doAction。

CommonBean作为中间传递的数据结构运载数据到相应的状态类里面进行处理,那业务要是需要doAction有返回值,怎么办呢?

我又增加了一个doActionReturn函数处理需要返回值的业务。

模式设计应用之状态

包名和类引用需要自己定义,在此不提供

代码实现:

/**  * Created by pengguangyu on 2016/3/30.  */  State.class public interface State {      public void doAction(CommonBean commonBean);      public CommonBean doActionReturn(CommonBean commonBean);  } NewState .class public class NewState implements State {      private Types typeState;      public NewState(){}      public NewState(Types typeState){         this.typeState = typeState;     }      public void BeforeAction(){         System.out.println("BeforeAction....");     }      public void NewAction(){         System.out.println("NewAction....");     }      public void AfterAction(){         System.out.println("AfterAction....");     }      @Override     public void doAction(CommonBean commonBean) {         switch (this.typeState){             case BeforeAction:BeforeAction();break;             case NewAction:NewAction();break;             case AfterAction:AfterAction();break;         }     }      @Override     public CommonBean doActionReturn(CommonBean commonBean) {         System.out.println("New Return....");         return null;     }      public static enum Types{         BeforeAction,NewAction,AfterAction     }  } CheckState .class public class CheckState implements State {      public CheckState(){}      @Override     public void doAction(CommonBean commonBean) {         System.out.println("Check....");     }      @Override     public CommonBean doActionReturn(CommonBean commonBean) {         System.out.println("Check Return....");         return null;     } } SendState .class public class SendState implements State {      public SendState(){}      @Override     public void doAction(CommonBean commonBean) {         System.out.println("Send....");     }      @Override     public CommonBean doActionReturn(CommonBean commonBean) {         System.out.println("Send Return....");         return null;     } }

上下文类:

/**  * Created by pengguangyu on 2016/3/30.  */ public class StateContext implements State {      private State state;      public static class StateContextHelper{         public static final StateContext INSTANCE = new StateContext();     }      public static StateContext getInstance(){         return StateContextHelper.INSTANCE;     }      public StateContext setStateWith(State state){         this.state = state;         return this;     }      public void setState(State state){         this.state = state;     }      public State getState() {         return state;     }       @Override     public void doAction(CommonBean commonBean) {         this.state.doAction(commonBean);     }      @Override     public CommonBean doActionReturn(CommonBean commonBean) {         this.state.doActionReturn(commonBean);         return null;     } }

通用Bean

public class CommonBean {  }

学习慢慢来,鸡汤还是要有的。

原文  http://boke.iflsy.com/archives/992
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