责任链模式

import java.util.Random;
import com.imooc.pattern.cor.handler.PriceHandler;
import com.imooc.pattern.cor.handler.PriceHandlerFactory;

/*
 * 客户，请求折扣，一级级申请折扣
 * 实际案例如：异常处理机制，dom事件，http filter等
 */
public class Customer {

    private PriceHandler priceHandler;

    public void setPriceHandler(PriceHandler priceHandler) {
        this.priceHandler = priceHandler;
    }

    public void requestDiscount(float discount){
        priceHandler.processDiscount(discount);
    }


    public static void main(String[] args){
        Customer customer = new Customer();
        customer.setPriceHandler(PriceHandlerFactory.createPriceHandler());

        Random rand = new Random();

        for(int i=1;i<=100;i++){
            System.out.print(i+":");
            customer.requestDiscount(rand.nextFloat());
        }


    }


}

/*
 * 价格处理人，负责处理客户折扣申请
 */
public abstract class PriceHandler {

    /*
     * 直接后继，用于传递请求
     */
    protected PriceHandler successor;

    public void setSuccessor(PriceHandler successor) {
        this.successor = successor;
    }

    /*
     * 处理折扣申请
     */
    public abstract  void processDiscount(float discount);

}

public class PriceHandlerFactory {

    /*
     * 创建PriceHandler的工厂方法
     */
    public static PriceHandler createPriceHandler() {

        PriceHandler sales = new Sales();
        PriceHandler lead = new Lead();
        PriceHandler man = new Manager();
        PriceHandler dir = new Director();
        PriceHandler vp = new VicePresident();
        PriceHandler ceo = new CEO();

        sales.setSuccessor(lead);
        lead.setSuccessor(man);
        man.setSuccessor(dir);
        dir.setSuccessor(vp);
        vp.setSuccessor(ceo);

        return sales;
    }

}

/*
 * 销售， 可以批准5%以内的折扣
 */
public class Sales extends PriceHandler {

    @Override
    public void processDiscount(float discount) {
        if(discount <= 0.05){
            System.out.format("%s批准了折扣：%.2f%n", this.getClass().getName(), discount);
        }else{
            //自己没权限处理就传递到上一级处理，形成责任链
            successor.processDiscount(discount);
        }

    }

}

/*
 * CEO， 可以批准55%以内的折扣
 * 折扣超出55%， 就拒绝申请
 */
public class CEO extends PriceHandler {

    @Override
    public void processDiscount(float discount) {
        if(discount<=0.55){
            System.out.format("%s批准了折扣:%.2f%n",this.getClass().getName(),discount);
        }else{
            System.out.format("%s拒绝了折扣:%.2f%n", this.getClass().getName(),discount);
        }

    }

}

参考：http://www.imooc.com/