Feign Client 捕获自定义异常

梦里梦外; 2022-01-29 14:47 1015阅读 0赞

在feign.hystrix.enable=false情况下，微服务提供方跑出自定义异常，微服务调用方怎么捕获这个自定义异常？

分两种情况：

1.如果微服务提供了接口声明，微服务调用工程引用了这个接口声明jar，有异常可以正常捕获。

2.如果微服务提供方以RestController的方式对外提供服务(例如/api/login)，则在微服务调用工程中要自定义错误解码处理。

3.还有一种说法是利用@HystrixCommand，人家的原话是：

Thanks. However, I think disabling Feign hystrix support (feign.hystrix.enabled=false) and using a @HystrixCommand on the caller method is simpler. That's what I'm doing now. – Abhijit Sarkar Nov 30 '16 at 8:56

And you use ignroeExceptions of @HystrixCommand? – Roi Ezra Dec 1 '16 at 11:50

Yes, using ignoreExceptions. – Abhijit Sarkar Dec 5 '16 at 3:37

方法2使用举例:

微服务提供方：

@RestController

@RequestMapping("api")

public class UserController\{

@Autowired

private UserFacadeService userFacadeService;

@RequestMapping(vlaue="/login", method=RequestMethod.POST)

public Token login(@RequestBody UserDto user) throws MyException\{

return userFacadeService.getLoginToken(user);

微服务调用方：

1.FeignClient中定义configuration采用自定义配置

@FeignClient(name="serviceProvide", fallback=UserServiceImpl.class, **configuration=\{KeepErrMsgConfiguration.class\}**)

public interface UserService\{

@RequestMapping(value="/api/login",  method=RequestMethod.POST)

public Token login(@RequestBody UserDto user) throws MyException;

@Service

public UserServiceImpl implements UserService\{

private final Logger log = LoggerFactory.getLogger(UserServiceImpl.class);

@Override

public Token login(@RequestBody UserDto user) throws MyException\{

log.error("调用\{\}异常：\{\}","serviceProvide:/api/login",user);

return null;

2.自定义错误解码

import com.alibaba.fastjson.JSON;

import com.test.common.exception.MyException;

import feign.Response;

import feign.Util;

import feign.codec.ErrorDecoder;

import org.apach.commons.langs3.StringUtils;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import java.io.IOException;

import java.util.Map;

class **MyErrDecoder** implements ErrorDecoder\{

private final Logger log = LoggerFactory.getLogger(MyErrDecoder.class);

private static final String ERR\_CODE="500";

private static final String SPLIT=":";

@Override

public Exception decode(String methodKey, Response response)\{

Exception excepiton = null;

try\{

//获取原始的返回内容

String json = Utils.toString(response.body().asReader());

//将返回的内容反序列化位Result,这里应根据自身项目做修改

Map<String, Object> result = JSON.parseObject(json, Map.class);

log.error("", result);

String msg = result.get("msg");

String code = String.valueOf(result.get("code"));

exception = new RuntimeException(json);

if(ERR\_CODE.equals(code))\{

if(StringUtils.isNotEmpty(msg))\{

if(msg.contains(SPLIT))\{

String \[\]msgArr = msg.split(SPLIT);

exception = new MyException(msgArr\[0\], msgArr\[1\]);

\}catch(IOException ex)\{

log.error(ex.getMessage(), ex);

3.自定义错误捕捉配置

import feign.codec.ErrorDecoder;

import org.springframework.context.annotation.Bean;

public class **KeepErrMsgConfiguration**\{

@Bean

public ErrorDecoder errorDecoder()\{

return new **MyErrDecoder**();

如果feign.hystrix.enable=true，则@FeignClient(name="serviceProvide", fallback=UserServiceImpl.class)中的fallback会被开启，但是也不会捕获到远端跑出的异常信息，要捕获异常需要使用到fallbackFactory

@FeignClient(name="serviceProvide", fallbackFactory = TestServiceFallback.class)

import feign.hystrix.FallbackFactory;

import org.apache.commons.lang3.StringUtils;

@Component

public class TestServiceFallback implements FallbackFactory<TestService> \{

private static final Logger LOG = LoggerFactory.getLogger(TestServiceFallback.class);

public static final String ERR\_MSG = "Test接口暂时不可用: ";

@Override

public TestService create(Throwable throwable) \{

String msg = throwable == null ? "" : throwable.getMessage();

if (!StringUtils.isEmpty(msg)) \{

LOG.error(msg);