软件设计实验十五与十六：职责链模式与命令模式

实验15：职责链模式
本次实验属于模仿型实验，通过本次实验学生将掌握以下内容：
1、理解职责链模式的动机，掌握该模式的结构；
2、能够利用职责链模式解决实际问题。

[实验任务一]：财务审批
某物资管理系统中物资采购需要分级审批，主任可以审批1万元及以下的采购单，部门经理可以审批5万元及以下的采购单，副总经理可以审批10万元及以下的采购单，总经理可以审批20万元及以下的采购单，20万元以上的采购单需要开职工大会确定。现用职责链模式设计该系统。
实验要求：

1. 提交类图；
2. 提交源代码；
3. 注意编程规范。

`package rjsj.no15;

public abstract class Leader {
protected String name;

//上级领导
protected Leader successor;

public Leader(String name) {
this.name = name;
}

public void setSuccessor(Leader successor) {
this.successor = successor;
}

protected abstract void handleRequest(ShoppingRequest request);
}`

`package rjsj.no15;

public class ShoppingRequest {
private String shoppingReason;
private double billMoney;

public ShoppingRequest(String shoppingReason,double billMoney){
this.shoppingReason = shoppingReason;
this.billMoney = billMoney;
}

public String getShoppingReason() {
return shoppingReason;
}

public void setShoppingReason(String shoppingReason) {
this.shoppingReason = shoppingReason;
}

public double getBillMoney() {
return billMoney;
}

public void setBillMoney(double billMoney) {
this.billMoney = billMoney;
}
}`

`package rjsj.no15;

public class Client {
public static void main(String[] args) {
Leader objDirector,objDepartmentManager,objViceManager,objGeneralManager;
objDirector = new Director("张主任");
objDepartmentManager = new DepartmentManager("刘部门经理");
objViceManager = new ViceManager("王副经理");
objGeneralManager = new GeneralManager("赵经理");

//设置上级
objDirector.setSuccessor(objDepartmentManager);
objDepartmentManager.setSuccessor(objViceManager);
objViceManager.setSuccessor(objGeneralManager);

ShoppingRequest shoppingRequest1 = new ShoppingRequest("买打印纸",1000);
ShoppingRequest shoppingRequest2 = new ShoppingRequest("购置电脑",20000);
ShoppingRequest shoppingRequest3 = new ShoppingRequest("购置空调",80000);
ShoppingRequest shoppingRequest4 = new ShoppingRequest("办公室装修",160000);
ShoppingRequest shoppingRequest5 = new ShoppingRequest("收购XX公司",1000000);

objDirector.handleRequest(shoppingRequest1);
System.out.println("");
objDirector.handleRequest(shoppingRequest2);
System.out.println("");
objDirector.handleRequest(shoppingRequest3);
System.out.println("");
objDirector.handleRequest(shoppingRequest4);
System.out.println("");
objDirector.handleRequest(shoppingRequest5);
System.out.println("****************************************");
}
}`

`package rjsj.no15;

//主任
class Director extends Leader{
public Director(String name) {
super(name);
}

public void handleRequest(ShoppingRequest request){
if (request.getBillMoney()<10000.00){
System.out.println(name + "主任处理物资采购" + request.getShoppingReason() + "采购资金为" + request.getBillMoney() + "元");
} else {
if (this.successor != null){
this.successor.handleRequest(request);
}
}
}
}

//部门经理
class DepartmentManager extends Leader{
public DepartmentManager(String name) {
super(name);
}

protected void handleRequest(ShoppingRequest request) {
if (request.getBillMoney()<50000.00){
System.out.println(name + "部门经理处理物资采购" + request.getShoppingReason() + "采购资金为" + request.getBillMoney() + "元");
} else {
if (this.successor != null){
this.successor.handleRequest(request);
}
}
}
}

//副经理
class ViceManager extends Leader{
public ViceManager(String name) {
super(name);
}

@Override
protected void handleRequest(ShoppingRequest request) {
if (request.getBillMoney()<100000.00){
System.out.println(name + "副经理处理物资采购" + request.getShoppingReason() + "采购资金为" + request.getBillMoney() + "元");
} else {
if (this.successor != null){
this.successor.handleRequest(request);
}
}
}
}

//总经理
class GeneralManager extends Leader{
public GeneralManager(String name) {
super(name);
}

@Override
protected void handleRequest(ShoppingRequest request) {
if (request.getBillMoney()<200000.00){
System.out.println(name + "总经理处理物资采购" + request.getShoppingReason() + "采购资金为" + request.getBillMoney() + "元");
} else {
System.out.println("董事会将开会处理物资采购" + request.getShoppingReason() + "采购资金为" + request.getBillMoney() + "元");
}
}
}`

实验16：命令模式
本次实验属于模仿型实验，通过本次实验学生将掌握以下内容：
1、理解命令模式的动机，掌握该模式的结构；
2、能够利用命令模式解决实际问题。

[实验任务一]：多次撤销和重复的命令模式
某系统需要提供一个命令集合（注：可以使用链表，栈等集合对象实现），用于存储一系列命令对象，并通过该命令集合实现多次undo()和redo()操作，可以使用加法运算来模拟实现。
实验要求：

1. 提交类图；
2. 提交源代码；
3. 注意编程规范。

`package rjsj.no16;

abstract class AbstractCommand{//抽象命令
public abstract int execute(int value);
public abstract int undo();
public abstract int redo();
}

class ConcreteCommand extends AbstractCommand{//具体命令
private Adder adder = new Adder();
private int value;

public int execute(int value) {
this.value=value;
return adder.add(value);
}

public int undo() {
return adder.add(-value);
}

public int redo() {
return adder.add(+value);
}
}

class CalculatorForm {//调用者
private AbstractCommand command;

public void setCommand(AbstractCommand command) {
this.command=command;
}

//业务方法，用于调用命令类的方法
public void compute(int value) {
int i = command.execute(value);
System.out.println("执行运算，运算结果为：" + i);
}

public void undo() {
int i = command.undo();
System.out.println("执行撤销，运算结果为：" + i);
}

public void redo() {
int i = command.redo();
System.out.println("执行重复，运算结果为：" + i);
}
}

class Adder {//接收者
private int num=0;

public int add(int value) {
num+=value;
return num;
}
}

class Client {//客户类
public static void main(String args[]) {
CalculatorForm form = new CalculatorForm();
ConcreteCommand command = new ConcreteCommand();
form.setCommand(command);

form.compute(10);
form.redo();
form.compute(5);
form.compute(10);
form.undo();

}
}`