设计模式-16-责任链模式

1.新建一个每个处理器都要继承的异常处理接口packagecom.xing.design.chainOfResponsibility;
publicinterfaceExcetionHandle {
/*** 处理异常 * @param type 异常类型*/voidhandle(Stringtype);
/***  设置下一个处理器* @param excetionHandle*/voidsetNextExcetionHandle(ExcetionHandleexcetionHandle);
}
2.建三个处理器类packagecom.xing.design.chainOfResponsibility;
publicclassRunTimeExcetionHandleimplementsExcetionHandle{
privateExcetionHandleexcetionHandle;
@Overridepublicvoidhandle(Stringtype) {
if("运行时异常".equals(type)) {
System.out.println("异常已被RunTimeExcetionHandle处理->"+type);
    }else {
// 处理不了，下一个System.out.println("RunTimeExcetionHandle处理不了->"+type+"，下一个");
excetionHandle.handle(type);
    }
  }
@OverridepublicvoidsetNextExcetionHandle(ExcetionHandleexcetionHandle) {
this.excetionHandle=excetionHandle;
  }
}
packagecom.xing.design.chainOfResponsibility;
publicclassClassNotFoundExcetionHandleimplementsExcetionHandle{
privateExcetionHandleexcetionHandle;
@Overridepublicvoidhandle(Stringtype) {
if("未找到类异常".equals(type)) {
System.out.println("异常已被ClassNotFoundExcetionHandle处理->"+type);
    }else {
// 处理不了，下一个System.out.println("ClassNotFoundExcetionHandle处理不了->"+type+"，下一个");
excetionHandle.handle(type);
    }
  }
@OverridepublicvoidsetNextExcetionHandle(ExcetionHandleexcetionHandle) {
this.excetionHandle=excetionHandle;
  }
}
packagecom.xing.design.chainOfResponsibility;
publicclassAllExcetionHandleimplementsExcetionHandle{
@Overridepublicvoidhandle(Stringtype) {
System.out.println("异常已被AllExcetionHandle处理->"+type);
  }
@OverridepublicvoidsetNextExcetionHandle(ExcetionHandleexcetionHandle) {
System.out.println("没有其他异常了，AllExcetionHandle就全捕捉掉"+excetionHandle);
  }
}
3.编写main方法测试，将上述处理器串成一条责任链packagecom.xing.design.chainOfResponsibility;
publicclassChainOfResponsibilityDemo {
publicstaticvoidmain(String[] args) {
StringrunTime="运行时异常";
StringclassNotFound="未找到类异常";
StringsysTem="系统异常";
Stringamazing="未知异常";
ExcetionHandlerunTimeExcetionHandle=newRunTimeExcetionHandle();
ExcetionHandleclassNotFoundExcetionHandle=newClassNotFoundExcetionHandle();
ExcetionHandleallExcetionHandle=newAllExcetionHandle();
// 组装责任链,运行时 -> 类未找到 -> 全部异常runTimeExcetionHandle.setNextExcetionHandle(classNotFoundExcetionHandle);
classNotFoundExcetionHandle.setNextExcetionHandle(allExcetionHandle);
// 从第一个处理类开始倒着处理上述异常：System.out.println("---------------------------开始处理【"+amazing+"】---------------------------");
runTimeExcetionHandle.handle(amazing);
System.out.println("---------------------------【"+amazing+"】处理完毕---------------------------");
System.out.println("---------------------------开始处理【"+sysTem+"】---------------------------");
runTimeExcetionHandle.handle(sysTem);
System.out.println("---------------------------【"+sysTem+"】处理完毕---------------------------");
System.out.println("---------------------------开始处理【"+classNotFound+"】---------------------------");
runTimeExcetionHandle.handle(classNotFound);
System.out.println("---------------------------【"+classNotFound+"】处理完毕---------------------------");
System.out.println("---------------------------开始处理【"+runTime+"】---------------------------");
runTimeExcetionHandle.handle(runTime);
System.out.println("---------------------------【"+runTime+"】处理完毕---------------------------");
  }
}