Java设计模式十九——责任链模式 (2)

1、编写抽象处理者角色Handler

package com.mazhichu.designpatterns.responsibility; import java.math.BigDecimal; /** * @ClassName: DealWorkInjuryRequestHandler * @Description: 抽象处理者角色 * @Author: Moore * @Date: 2020-06-29 9:39 * @Version: V1.0 */ public abstract class DealWorkInjuryRequestHandler { /** * 如果处理不了，设置后继处理者 */ protected DealWorkInjuryRequestHandler successor; /** * 处理请求的方法 * @param compensationPayments */ public abstract void dealWorkInjury(BigDecimal compensationPayments); public void setSuccessor(DealWorkInjuryRequestHandler successor) { this.successor = successor; } }

2、编写具体处理者角色老李的亲戚老赵。

package com.mazhichu.designpatterns.responsibility; import java.math.BigDecimal; /** * @ClassName: LaoZhaoHandler * @Description: 具体处理者角色：老赵 * @Author: Moore * @Date: 2020-06-29 9:40 * @Version: V1.0 */ public class LaoZhaoHandler extends DealWorkInjuryRequestHandler{ @Override public void dealWorkInjury(BigDecimal compensationPayments) { System.out.println("老赵：老李别担心，赔偿款一共"+compensationPayments+"元，我已经找了他们大老板去处理了。"); successor.dealWorkInjury(compensationPayments); } }

3、编写具体处理者角色承建公司大老板。

package com.mazhichu.designpatterns.responsibility; import java.math.BigDecimal; /** * @ClassName: LaoZhaoHandler * @Description: 具体处理者角色：承建公司大老板 * @Author: Moore * @Date: 2020-06-29 9:40 * @Version: V1.0 */ public class BossHandler extends DealWorkInjuryRequestHandler{ @Override public void dealWorkInjury(BigDecimal compensationPayments) { if(compensationPayments.compareTo(BigDecimal.valueOf(100000))>0){ System.out.println("大老板"+compensationPayments+"赔偿款，先拖拖，找人也不行。"); }else { System.out.println("大老板"+compensationPayments+"赔偿款，才这点钱，让项目经理去处理。"); successor.dealWorkInjury(compensationPayments); } } }

4、编写具体处理者角色包工头

package com.mazhichu.designpatterns.responsibility; import java.math.BigDecimal; import java.math.MathContext; /** * @ClassName: LaoZhaoHandler * @Description: 具体处理者角色：承建公司包工头 * @Author: Moore * @Date: 2020-06-29 9:40 * @Version: V1.0 */ public class ContractorHandler extends DealWorkInjuryRequestHandler{ @Override public void dealWorkInjury(BigDecimal compensationPayments) { if(compensationPayments.compareTo(BigDecimal.valueOf(30000))>0){ System.out.println("包工头：上面压我，倒霉玩意，"+compensationPayments+"赔偿款，我要赔"+compensationPayments.multiply(BigDecimal.valueOf(0.3), MathContext.DECIMAL32)); }else { System.out.println("包工头：上面压我，倒霉玩意，我要自己掏"+compensationPayments+"赔偿款。"); } } }

5、我们看看老李的维权之路是怎样的，编写客户端请求发送者角色老李。

package com.mazhichu.designpatterns.responsibility; import java.math.BigDecimal; /** * @ClassName: Laoli * @Description: 请求发送者角色：老李 * @Author: Moore * @Date: 2020-06-29 10:44 * @Version: V1.0 */ public class Laoli { public static void main(String[] args) { DealWorkInjuryRequestHandler lzHandler = new LaoZhaoHandler(); DealWorkInjuryRequestHandler bossHandler = new BossHandler(); DealWorkInjuryRequestHandler manageHandler = new ManageHandler(); DealWorkInjuryRequestHandler contractorHandler = new ContractorHandler(); lzHandler.setSuccessor(bossHandler); bossHandler.setSuccessor(manageHandler); manageHandler.setSuccessor(contractorHandler); lzHandler.dealWorkInjury(BigDecimal.valueOf(120000)); System.out.println("-------------------------------------------------\n"); lzHandler.dealWorkInjury(BigDecimal.valueOf(80000)); System.out.println("-------------------------------------------------\n"); lzHandler.dealWorkInjury(BigDecimal.valueOf(20000)); } }

6、查看运行结果：

可以看出，在代码实例中我们创建了四个处理者对象，并指定第一个处理者对象的下家是第二个处理者对象，一直到第四个处理对象包工头为止。然后客户端老李将请求传递给第一个处理者对象老赵，老李不用再关心具体是谁处理了工伤赔偿。他只知道，如果没有老赵，他最终可能只能认命，听话不闹事就能拿到工资就好。

老李是太胆小又怕事，其实他完全可以拿着伤残鉴定去劳动局监察大队去投诉，这样就会在责任链上多一个具体处理者角色，监察大队会继续追查下去，找到链上该负责的处理对象，环环相扣，最终给老李一个交代。

总结