在Spring Cloud 微服务中不可避免的使用Feign来远程调用其他服务接口,一般情况下,会在报文格式中冗余一个响应码和响应信息的字段,例如:
{"msg":"产品不存在","code":40005,"data": null}
在调用Feign接口时,我们都希望直接返回的就是想要的结果,如果每个接口的返回数据都要像上边一样,就需要对返回的数据进行处理,是非常繁琐的,而且会造成代码的冗余,但是当被调用服务抛出业务异常时,FeignClient抛出的异常是被封装过的,无法获得有用的信息,所以就需要设计一套机制来处理返回数据。
下面是我的解决方案:
1.统一封装异常码
/**
* @author:JZ
* @date:2020/3/15
*/publicenum ResultCode{SUCCESS(00000,"成功"),FAIL(99999,"失败"),SYSTEM_EXCEPTION(10000,"系统异常");private Integer code;private String message;ResultCode(Integer code, String message){this.code= code;this.message= message;}public IntegergetCode(){returnthis.code;}public StringgetMessage(){returnthis.message;}}
2.统一异常
这里只是父类,可以延伸出子类
import com.jz.shop.commons.enums.ResultCode;import lombok.Data;/**
* @author:JZ
* @date:2020/4/19
*/@DatapublicclassBaseExceptionextendsRuntimeException{private Integer code;private String msg;publicBaseException(){super();}publicBaseException(ResultCode resultCode){super(resultCode.getMessage());this.code= resultCode.getCode();this.msg= resultCode.getMessage();}publicBaseException(Integer code, String message){super(message);this.code= code;this.msg= message;}}
3.全局异常处理器
由全局异常处理器处理所有异常,并对返回结果进行处理
package com.jz.shop.commons.handler.exception;import com.jz.shop.commons.enums.ResultCode;import com.jz.shop.commons.execptions.BaseException;import com.jz.shop.commons.model.Result;import lombok.extern.slf4j.Slf4j;import org.springframework.http.HttpStatus;import org.springframework.web.bind.annotation.ExceptionHandler;import org.springframework.web.bind.annotation.ResponseStatus;import org.springframework.web.bind.annotation.RestControllerAdvice;import javax.servlet.http.HttpServletRequest;/**
* @author:JZ
* @date:2020/5/16
*/@Slf4j@RestControllerAdvicepublicclassGlobalExceptionHandler{/**
* 系统异常处理器
* @param throwable
* @param request
* @return
*/@ExceptionHandler(Throwable.class)@ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)// 指定http状态码,如果不指定为非2xx,feign不会抛出异常public ResultsystemExceptionHandler(Throwable throwable, HttpServletRequest request){
log.error("URL:{} ,系统异常", request.getRequestURI(), throwable);return Result.fail(Result.success(ResultCode.SYSTEM_EXCEPTION));}/**
* 自定义异常处理器
*/@ExceptionHandler(BaseException.class)@ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)// 指定http状态码,如果不指定为非2xx,feign不会抛出异常public ResultbaseExceptionHandler(BaseException baseException, HttpServletRequest request){
log.warn("URL:{} ,业务异常", request.getRequestURI());return Result.fail(baseException.getCode(), baseException.getMsg());}}
4.自定义处理Feign调用异常
实现 Feign 的ErrorDecoder
接口,抛出自定义异常。
import com.alibaba.fastjson.JSONObject;import com.jz.shop.commons.execptions.BaseException;import com.jz.shop.commons.execptions.system.SystemException;import com.jz.shop.commons.model.Result;import feign.Response;import feign.Util;import feign.codec.ErrorDecoder;import lombok.extern.slf4j.Slf4j;/**
* feign异常处理
* @author:JZ
* @date:2020/5/16
*/@Slf4jpublicclassFeignErrorDecoderimplementsErrorDecoder{@Overridepublic Exceptiondecode(String s, Response response){
BaseException baseException= null;try{
String errorContent= Util.toString(response.body().asReader());
Result result= JSONObject.parseObject(errorContent, Result.class);
baseException=newBaseException(result.getCode(), result.getMsg());}catch(Exception e){
log.error("处理FeignClient 异常错误");
e.printStackTrace();return SystemException.DEFAULT_SYSTEM_EXCEPTION;}return baseException;}}
5.总结
经过上述处理即使连续调用了多个Feign接口,异常信息也会被逐级传递,同时不用影响Hmily
。