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责任链，火车一样，一节一节串起来。类似
a.setNext(b)；
b.setNext©;
c.setNext(d);
…
这里以多步校验做举例，正常方法中要写好多个if else

定义一个接口

package com.example.chain;/*** 订单校验**/
public interface OrderCreateValidator {/*** 设置下一个校验器** @param nextValidator*/public void setNext(OrderCreateValidator nextValidator);public OrderCreateValidator getNext();/*** 校验** @param request* @throws OrderException 订单异常*/public void validate(OrderCreateRequest request) throws OrderException;
}

类实现接口

package com.example.chain.orgin;import com.example.chain.OrderCreateRequest;
import com.example.chain.OrderCreateValidator;
import com.example.chain.OrderException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;@Service
public class UserValidator2 implements OrderCreateValidator {private OrderCreateValidator nextValidator;@Overridepublic void setNext(OrderCreateValidator next) {this.nextValidator = next;}@Overridepublic OrderCreateValidator getNext() {return nextValidator;}@Overridepublic void validate(OrderCreateRequest request) throws OrderException {System.out.println("UserValidator doValidate");}}
package com.example.chain.orgin;import com.example.chain.OrderCreateRequest;
import com.example.chain.OrderCreateValidator;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;@Service
public class Goo