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；

public class Client {

    public static void main(String[] args) {
        PurchaseRequest purchaseRequest1 = new PurchaseRequest(1, 5600, 1);
        PurchaseRequest purchaseRequest2 = new PurchaseRequest(1, 25620, 2);
        PurchaseRequest purchaseRequest3 = new PurchaseRequest(1, 96541, 3);
        PurchaseRequest purchaseRequest4 = new PurchaseRequest(1, 152345, 4);
        PurchaseRequest purchaseRequest5 = new PurchaseRequest(1, 235685, 5);

        Director director = new Director("主任");
        DepartmentManager departmentManager = new DepartmentManager("部门经理");
        ViceManager viceManager = new ViceManager("副总经理");
        GeneralManager generalManager = new GeneralManager("总经理");

        director.setApprover(departmentManager);
        departmentManager.setApprover(viceManager);
        viceManager.setApprover(generalManager);

        System.out.println(purchaseRequest1.toString());
        director.processRequest(purchaseRequest1);
        System.out.println("-------------------------------");

        System.out.println(purchaseRequest2.toString());
        director.processRequest(purchaseRequest2);
        System.out.println("-------------------------------");

        System.out.println(purchaseRequest3.toString());
        director.processRequest(purchaseRequest3);
        System.out.println("-------------------------------");

        System.out.println(purchaseRequest4.toString());
        director.processRequest(purchaseRequest4);
        System.out.println("-------------------------------");

        System.out.println(purchaseRequest5.toString());
        director.processRequest(purchaseRequest5);
        System.out.println("-------------------------------");

    }

}

public class PurchaseRequest {

    private int type;
    private float price;
    private int id;

    public PurchaseRequest(int type, float price, int id) {
        this.type = type;
        this.price = price;
        this.id = id;
    }

    public int getType() {
        return type;
    }

    @Override
    public String toString() {
        return this.getId() + "号物资" + this.getPrice() + "元";
    }

    public float getPrice() {
        return price;
    }

    public int getId() {
        return id;
    }
}

public class ViceManager extends Approver {

    public ViceManager(String name) {
        super(name);
    }

    @Override
    public void processRequest(PurchaseRequest purchaseRequest) {
        if (purchaseRequest.getPrice() > 50000 && purchaseRequest.getPrice() <= 100000) {
            System.out.println("请求编号id => " + purchaseRequest.getId() + "被" + this.position + "处理");
        } else {
            approver.processRequest(purchaseRequest);
        }

    }
}

public class GeneralManager extends Approver {

    public GeneralManager(String name) {
        super(name);
    }

    @Override
    public void processRequest(PurchaseRequest purchaseRequest) {
        if (purchaseRequest.getPrice() > 100000 && purchaseRequest.getPrice() <= 200000) {
            System.out.println("请求编号id => " + purchaseRequest.getId() + "被" + this.position + "处理");
        } else {
            System.out.println("需要开员工大会确定");
        }

    }
}

public class Director extends Approver {

    public Director(String name) {
        super(name);
    }

    @Override
    public void setApprover(Approver approver) {
        super.setApprover(approver);
    }

    @Override
    public void processRequest(PurchaseRequest purchaseRequest) {
        if (purchaseRequest.getPrice() <= 10000) {
            System.out.println("请求编号id => " + purchaseRequest.getId() + "被" + this.position + "处理");
        } else {
            approver.processRequest(purchaseRequest);
        }

    }
}

public class DepartmentManager extends Approver {

    public DepartmentManager(String name) {
        super(name);
    }

    @Override
    public void processRequest(PurchaseRequest purchaseRequest) {
        if (purchaseRequest.getPrice() > 10000 && purchaseRequest.getPrice() <= 50000) {
            System.out.println("请求编号id => " + purchaseRequest.getId() + "被" + this.position + "处理");
        } else {
            approver.processRequest(purchaseRequest);
        }

    }
}

public abstract class Approver {

    // 下一个后继者
    Approver approver;
    // 职位
    String position;

    public Approver(String position) {
        this.position = position;
    }

    // 下一个处理者

    public void setApprover(Approver approver) {
        this.approver = approver;
    }

    // 处理审批请求的方法
    public abstract void processRequest(PurchaseRequest purchaseRequest);
}