简介：以对象来代表实际行动，命令对象可以把行动(action) 及其参数封装起来，这些行动可以被

• 重复多次
• 取消（如果该对象有的话）
• 取消后又再重做

目的：

总结：

 

组成：对象，行动

1，对象

package com.design.l.command;/** * 程序设计员 */public class Programmer {        private String userName;    public Programmer(String userName) {        super();        this.userName = userName;    }            public void handleDemand(){        System.out.println("程序员 : " + userName + " ,正在处理新需求 ... ...");    }    public void handleBug(){        System.out.println("程序员 : " + userName + " ,正在处理Bug ... ...");    }    public void handleProblem(){        System.out.println("程序员 : " + userName + " ,正在处理线上问题 ... ...");    }    public String getUserName() {        return userName;    }    public void setUserName(String userName) {        this.userName = userName;    }}

 

package com.design.l.command;import java.util.ArrayList;import java.util.Arrays;import java.util.List;/** * 产品经理 */public class ProductManager {        //任务集合    private List
     
       taskList;    //程序员    private List
      
        programmerList;    private static final int TASK_MAX_NUM = 4;//任务最大数量    private int idx = 0;    public ProductManager(Programmer ... programmers) {        super();        this.taskList = new ArrayList<>();        this.programmerList = Arrays.asList(programmers);    }        //新增任务    public void addTaskToProduct(TaskService taskService){        taskList.add(taskService);    }        //分配任务    public void assignments(){        TaskService[] copy = new TaskService[taskList.size() > TASK_MAX_NUM ? taskList.size() - TASK_MAX_NUM : 0];        for ( int i = 0; i < TASK_MAX_NUM && i < taskList.size(); i ++){            taskList.get(i).handle();        }                System.arraycopy(taskList.toArray(), TASK_MAX_NUM > taskList.size() ? taskList.size() : TASK_MAX_NUM, copy, 0, copy.length);        taskList = Arrays.asList(copy);    }        //获取程序员    public Programmer chooseProgrammer(){        return programmerList.get(idx == programmerList.size() ? 0 : idx ++);     }        //打印出未处理的任务    public void printTask(){        if(taskList == null || taskList.size() == 0){            System.out.println("----无任务----");            return ;        }                System.out.println("----剩余任务----");        for(TaskService task : taskList){            System.out.println(task);        }    }}
      
     

 

package com.design.l.command;/** * 销售人员 */public class Sales {        private String userName;    private ProductManager productManager;//产品经理        public Sales(String userName) {        super();        this.userName = userName;    }    public Sales(String userName, ProductManager productManager) {        super();        this.userName = userName;        this.productManager = productManager;    }            public void putDemand(){        System.out.println("业务员 : " + userName + ", 提出新需求  ... ... ");        productManager.addTaskToProduct(new DemandTaskServiceImpl(productManager.chooseProgrammer()));    }    public void putBug(){        System.out.println("业务员 : " + userName + ", 提出新Bug  ... ... ");        productManager.addTaskToProduct(new BugTaskServiceImpl(productManager.chooseProgrammer()));    }    public void putProblem(){        System.out.println("业务员 : " + userName + ", 提出线上问题     ... ... ");        productManager.addTaskToProduct(new ProblemTaskServiceImpl(productManager.chooseProgrammer()));    }        public String getUserName() {        return userName;    }    public void setUserName(String userName) {        this.userName = userName;    }    public ProductManager getProductManager() {        return productManager;    }    public void setProductManager(ProductManager productManager) {        this.productManager = productManager;    }}

 

2，行为

package com.design.l.command;/** * 任务接口 */public interface TaskService {    /**     * 任务处理方法     */    void handle();}

 

package com.design.l.command;/** * 新需求任务 */public class DemandTaskServiceImpl implements TaskService {        private Programmer programmer;    public DemandTaskServiceImpl(Programmer programmer) {        super();        this.programmer = programmer;    }    @Override    public void handle() {        programmer.handleDemand();    }}

 

package com.design.l.command;/** * Bug任务 */public class BugTaskServiceImpl implements TaskService {        private Programmer programmer;    public BugTaskServiceImpl(Programmer programmer) {        super();        this.programmer = programmer;    }    @Override    public void handle() {        programmer.handleBug();    }}

 

package com.design.l.command;/** * 线上问题任务 */public class ProblemTaskServiceImpl implements TaskService {    private Programmer programmer;    public ProblemTaskServiceImpl(Programmer programmer) {        super();        this.programmer = programmer;    }    @Override    public void handle() {        programmer.handleProblem();    }}

 

3，Main

package com.design.l.command;/** * 12-命令模式 */public class MainTest {        public static void main(String[] args) {                Programmer programmerA = new Programmer("程序员A");        ProductManager productManager = new ProductManager(programmerA);        Sales salesA = new Sales("业务员A", productManager);        Sales salesB = new Sales("业务员B", productManager);        Sales salesC = new Sales("业务员C", productManager);        Sales salesD = new Sales("业务员D", productManager);                salesA.putDemand();        salesA.putBug();        salesB.putProblem();        salesC.putBug();        salesD.putProblem();                productManager.assignments();        productManager.printTask();                productManager.assignments();        productManager.printTask();    }}

4，Result

业务员 : 业务员A, 提出新需求  ... ... 业务员 : 业务员A, 提出新Bug  ... ... 业务员 : 业务员B, 提出线上问题     ... ... 业务员 : 业务员C, 提出新Bug  ... ... 业务员 : 业务员D, 提出线上问题     ... ... 程序员 : 程序员A ,正在处理新需求 ... ...程序员 : 程序员A ,正在处理Bug ... ...程序员 : 程序员A ,正在处理线上问题 ... ...程序员 : 程序员A ,正在处理Bug ... ...----剩余任务----com.design.l.command.ProblemTaskServiceImpl@15db9742程序员 : 程序员A ,正在处理线上问题 ... ...----无任务----