Java设计模式-责任链模式，应用接口多个参数验证，订单多个费用的计算
1.定义请求和返回对象的上下文对象
package com.example.core.mydemo.java.filter;
import java.time.LocalDateTime;
public class OrderReqContext {
/**
* 租客会员号
*/
String memNo;
/**
* 订单号
*/
String orderNo;
/**
* 开始时间
*/
private LocalDateTime requestTime;
/**
* 返回对象
*/
private String responseText;
public String getResponseText() {
return responseText;
}
public void setResponseText(String responseText) {
this.responseText = responseText;
}
public String getMemNo() {
return memNo;
}
public void setMemNo(String memNo) {
this.memNo = memNo;
}
public String getOrderNo() {
return orderNo;
}
public void setOrderNo(String orderNo) {
this.orderNo = orderNo;
}
public LocalDateTime getRequestTime() {
return requestTime;
}
public void setRequestTime(LocalDateTime requestTime) {
this.requestTime = requestTime;
}
}2.定义异常对象
package com.example.core.mydemo.java.filter;
public class OrderFilterException extends RuntimeException{
private String errorCode;
/**
* 异常的描述信息
*/
private String errorMsg;
/**
* 异常可能附加的对象，方便前端输出展示
*/
private Object extra;
public OrderFilterException(String errorCode, String errorMsg,Throwable cause) {
super(cause);
this.errorCode = errorCode;
this.errorMsg = errorMsg;
this.extra = null;
}
public OrderFilterException(String errorCode, String errorMsg,Object extra,Throwable cause) {
super(cause);
this.errorCode = errorCode;
this.errorMsg = errorMsg;
this.extra = extra;
}
public OrderFilterException(String errorCode, String errorMsg,Object extra) {
super(errorMsg);
this.errorCode = errorCode;
this.errorMsg = errorMsg;
this.extra = extra;
}
public OrderFilterException(String errorCode,String errorMsg){
super(errorMsg);
this.errorCode =errorCode;
this.errorMsg =errorMsg;
}
public String getErrorCode() {
return errorCode;
}
public void setErrorCode(String errorCode) {
this.errorCode = errorCode;
}
public String getErrorMsg() {
return errorMsg;
}
public void setErrorMsg(String errorMsg) {
this.errorMsg = errorMsg;
}
public Object getExtra() {
return extra;
}
public void setExtra(Object extra) {
this.extra = extra;
}
}3.定义接口
package com.example.core.mydemo.java.filter;
public interface OrderFilter {
/**
* 检查该订单的请求是否合法，如果不合法，将抛出OrderFilterException
* @param requestContext
*/
public void validate(OrderReqContext requestContext) throws OrderFilterException;
}4.定义责任链类
package com.example.core.mydemo.java.filter;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Service;
import javax.annotation.PostConstruct;
import java.util.ArrayList;
import java.util.List;
@Service
public class OrderFilterChain implements OrderFilter, ApplicationContextAware {
private List<OrderFilter> orderFilterList = new ArrayList<>();
private ApplicationContext applicationContext;
/**
* 单元测试类模拟
*/
public void initTest(){
/* 参数检测 */
orderFilterList.add(new ParamsFilter());
/** 节假日检测 **/
orderFilterList.add(new HolidayFilter());
/** other其他 **/
}
/**
* 容器启动时候加载
*/
@PostConstruct
private void init(){
/* 参数检测 */
orderFilterList.add(applicationContext.getBean(ParamsFilter.class));
/** 节假日检测 **/
orderFilterList.add(applicationContext.getBean(HolidayFilter.class));
/** other其他 **/
}
@Override
public void validate(OrderReqContext context) throws OrderFilterException {
if(orderFilterList.size()==0){
throw new RuntimeException("cannot be init");
}
for(OrderFilter filter: orderFilterList){
filter.validate(context);
}
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.applicationContext = applicationContext;
}
}5.实现类1
package com.example.core.mydemo.java.filter;
import com.google.gson.Gson;
import org.springframework.stereotype.Service;
@Service("holidayFilter")
public class HolidayFilter implements OrderFilter {
@Override
public void validate(OrderReqContext requestContext) throws OrderFilterException{
requestContext.setResponseText("节假日");
System.out.println("节假日检测完成,参数=" + new Gson().toJson(requestContext));
}
}6.实现类2
package com.example.core.mydemo.java.filter;
import com.google.gson.Gson;
import org.springframework.stereotype.Service;
@Service("paramsFilter")
public class ParamsFilter implements OrderFilter {
@Override
public void validate(OrderReqContext requestContext) throws OrderFilterException{
requestContext.setResponseText("参数");
System.out.println("参数检测完成,参数="+ new Gson().toJson(requestContext));
}
}7.测试类
package com.example.core.mydemo.java.filter;
import java.time.LocalDateTime;
/**
* 参数检测完成,参数={"memNo":"123111","orderNo":"DD123456789","requestTime":{"date":{"year":2024,"month":4,"day":19},"time":{"hour":17,"minute":50,"second":57,"nano":943000000}},"responseText":"参数"}
* 节假日检测完成,参数={"memNo":"123111","orderNo":"DD123456789","requestTime":{"date":{"year":2024,"month":4,"day":19},"time":{"hour":17,"minute":50,"second":57,"nano":943000000}},"responseText":"节假日"}
* 返回对象=节假日
*/
public class FilterTest {
public static void main(String[] args) {
OrderFilterChain orderFilterChain = new OrderFilterChain();
//初始化
orderFilterChain.initTest();
//前置检查
OrderReqContext orderReqContext = initContext();
//验证参数
orderFilterChain.validate(orderReqContext);
System.out.println("返回对象=" + orderReqContext.getResponseText());
}
private static OrderReqContext initContext() {
OrderReqContext orderReqContext = new OrderReqContext();
orderReqContext.setOrderNo("DD123456789");
orderReqContext.setMemNo("123111");
orderReqContext.setRequestTime(LocalDateTime.now());
return orderReqContext;
}
}
