责任链模式-java

1、spring依赖注入模式

@Configuration
public class ChainConfig {

    @Bean
    public ChainSpringFactory chainSpringFactory(List<IHandler<DemoOne,Boolean>> handlerList){
        return new ChainSpringFactory(handlerList);
    }

}

public class DemoOne {
}

public abstract class IHandler<T,R> {
    public IHandler<T,R> nextHandler;

    public void setNextHandler(IHandler<T,R> nextHandler) {
        this.nextHandler = nextHandler;
    }

    public boolean hasNext() {
        return this.nextHandler != null;
    }
    /**
     * 处理责任链逻辑， 执行下个环节
     */
    public R handle(T t){
        if(hasNext()){
            return nextHandler.handle(t);
        }
        return  null;
    };

}

public class ChainSpringFactory <T,R> {
    private IHandler<T,R> first;

    /**
     * 存放系统中责任链具体处理类
     * @param handlerList
     */
    public  ChainSpringFactory(List<IHandler<T,R>> handlerList) {
        Assert.notEmpty(handlerList,"无责任实现bean");

        for (int i = 0; i < handlerList.size()-1; i++) {
            handlerList.get(i).setNextHandler(handlerList.get(i+1));
        }
        first=handlerList.get(0);
    }

    /**
     * 执行具体业务场景中的责任链集合
     */
    public R executeHandle(T productDto) {
        return first.handle(productDto);
    }
}

</