請求的鏈式處理——職責鏈模式（三）

//採購單：請求類
class PurchaseRequest {
	private double amount;  //採購金額
	private int number;  //採購單編號
	private String purpose;  //採購目的
	
	public PurchaseRequest(double amount, int number, String purpose) {
		this.amount = amount;
		this.number = number;
		this.purpose = purpose;
	}
	
	public void setAmount(double amount) {
		this.amount = amount;
	}
	
	public double getAmount() {
		return this.amount;
	}
	
	public void setNumber(int number) {
		this.number = number;
	}
	
	public int getNumber() {
		return this.number;
	}
	
	public void setPurpose(String purpose) {
		this.purpose = purpose;
	}
	
	public String getPurpose() {
		return this.purpose;
	}
}

//審批者類：抽象處理者
abstract class Approver {
	protected Approver successor; //定義後繼物件
	protected String name; //審批者姓名
	
	public Approver(String name) {
		this.name = name;
	}

	//設定後繼者
	public void setSuccessor(Approver successor) { 
		this.successor = successor;
	}

    //抽象請求處理方法
    public abstract void processRequest(PurchaseRequest request);
}

//主任類：具體處理者
class Director extends Approver {
	public Director(String name) {
		super(name);
	}
	
    //具體請求處理方法
 	public void processRequest(PurchaseRequest request) {
 		if (request.getAmount() < 50000) {
 			System.out.println("主任" + this.name + "審批採購單：" + request.getNumber() + "，金額：" + request.getAmount() + "元，採購目的：" + request.getPurpose() + "。");  //處理請求
 		}
 		else {
 			this.successor.processRequest(request);  //轉發請求
 		}	
 	}
}

//副董事長類：具體處理者
class VicePresident extends Approver {
	public VicePresident(String name) {
		super(name);
	}
	
    //具體請求處理方法
 	public void processRequest(PurchaseRequest request) {
 		if (request.getAmount() < 100000) {
 			System.out.println("副董事長" + this.name + "審批採購單：" + request.getNumber() + "，金額：" + request.getAmount() + "元，採購目的：" + request.getPurpose() + "。");  //處理請求
 		}
 		else {
 			this.successor.processRequest(request);  //轉發請求
 		}	
 	}
}

//董事長類：具體處理者
class President extends Approver {
	public President(String name) {
		super(name);
	}
	
    //具體請求處理方法
 	public void processRequest(PurchaseRequest request) {
 		if (request.getAmount() < 500000) {
 			System.out.println("董事長" + this.name + "審批採購單：" + request.getNumber() + "，金額：" + request.getAmount() + "元，採購目的：" + request.getPurpose() + "。");  //處理請求
 		}
 		else {
 			this.successor.processRequest(request);  //轉發請求
 		}
 	}
}

//董事會類：具體處理者
class Congress extends Approver {
	public Congress(String name) {
		super(name);
	}
	
    //具體請求處理方法
 	public void processRequest(PurchaseRequest request) {
 		System.out.println("召開董事會審批採購單：" + request.getNumber() + "，金額：" + request.getAmount() + "元，採購目的：" + request.getPurpose() + "。");	    //處理請求
 	}    
}

class Client {
	public static void main(String[] args) {
		Approver wjzhang,gyang,jguo,meeting;
		wjzhang = new Director("張無忌");
		gyang = new VicePresident("楊過");
		jguo = new President("郭靖");
		meeting = new Congress("董事會");
	
		//建立職責鏈
		wjzhang.setSuccessor(gyang);
		gyang.setSuccessor(jguo);
		jguo.setSuccessor(meeting);
		
		//建立採購單
		PurchaseRequest pr1 = new PurchaseRequest(45000,10001,"購買倚天劍");
		wjzhang.processRequest(pr1);
		
		PurchaseRequest pr2 = new PurchaseRequest(60000,10002,"購買《葵花寶典》");
		wjzhang.processRequest(pr2);
	
		PurchaseRequest pr3 = new PurchaseRequest(160000,10003,"購買《金剛經》");
		wjzhang.processRequest(pr3);

		PurchaseRequest pr4 = new PurchaseRequest(800000,10004,"購買桃花島");
		wjzhang.processRequest(pr4);
	}
}