在spring cloud feign调用微服务时，打印输出请求响应日志，可以快速定位问题，以下是详细步聚

1. 增加config

@Configuration
public class FeignConfig {
    @Bean
    Logger.Level feignLevel() {
        return Logger.Level.FULL;
    }
    @Bean
    Logger feignLogger(){
        return new FeignLogger();
    }
}

2. 重写feign.Logger

public class FeignLogger extends feign.Logger {

    private final org.slf4j.Logger logger;

    public FeignLogger() {
        this(feign.Logger.class);
    }

    public FeignLogger(Class<?> clazz) {
        this(LoggerFactory.getLogger(clazz));
    }

    public FeignLogger(String name) {
        this(LoggerFactory.getLogger(name));
    }

    FeignLogger(org.slf4j.Logger logger) {
        this.logger = logger;
    }


    @Override
    protected void logRequest(String configKey, Level logLevel, Request request) {
        if (logger.isInfoEnabled()) {
            super.logRequest(configKey, logLevel, request);
        }
    }

    @Override
    protected Response logAndRebufferResponse(String configKey, Level logLevel, Response response, long elapsedTime)
            throws IOException {
        if (logger.isInfoEnabled()) {
            return super.logAndRebufferResponse(configKey, logLevel, response, elapsedTime);
        }
        return response;
    }

    @Override
    protected void log(String configKey, String format, Object... args) {
        if (logger.isInfoEnabled()) {
            logger.info(String.format(methodTag(configKey) + format, args));
        }
    }
}

3. feignClient使用注解配置config类

@FeignClient(path = "/", name="user-service-login",url = "${user-service}", configuration = {FeignConfig.class})
public interface LoginApi {
    /**
     * 用户登录
     * @param loginVo
     * @return
     * @throws Exception
     */
    @PostMapping(path = "/login",consumes = "application/json")
    @ResponseBody
    ResultEntity<Object> login(@RequestBody LoginVo loginVo) throws Exception;

    /**
     * 用户注册
     * @param registerVO
     * @return
     * @throws Exception
     */
    @PostMapping(path = "/regist",consumes = "application/json")
    @ResponseBody
    ResultEntity<Object> regist(@RequestBody RegisterVO registerVO) throws Exception;

}

4. yaml配置

#配置feignClient类所在的包名
logging:
  level:
    com.xxx.web.admin.feignapi.client:info

输出效果

v_1.4.0 INFO 2020-06-13 15:59:03 【[LoginApi#login] ---> POST http://127.0.0.1:8083/user-service/login HTTP/1.1】 feign.Logger(58) [http-nio-8080-exec-1] []

v_1.4.0  INFO 2020-06-13 15:59:03 【[LoginApi#login] Content-Type: application/json】 feign.Logger(58) [http-nio-8080-exec-1] []

v_1.4.0  INFO 2020-06-13 15:59:03 【[LoginApi#login] Content-Length: 83】 feign.Logger(58) [http-nio-8080-exec-1] []

v_1.4.0  INFO 2020-06-13 15:59:03 【[LoginApi#login] 】 feign.Logger(58) [http-nio-8080-exec-1] []

v_1.4.0  INFO 2020-06-13 15:59:03 【[LoginApi#login] {"userName":"NjcyMDkyNjA5QHFNvbQ==","password":"RlbjExMQ==","remmberMe":false}】 feign.Logger(58) [http-nio-8080-exec-1] []

v_1.4.0  INFO 2020-06-13 15:59:03 【[LoginApi#login] ---> END HTTP (83-byte body)】 feign.Logger(58) [http-nio-8080-exec-1] []

v_1.4.0  INFO 2020-06-13 15:59:03 【[LoginApi#login] <--- HTTP/1.1 200 (25ms)】 feign.Logger(58) [http-nio-8080-exec-1] []

v_1.4.0  INFO 2020-06-13 15:59:03 【[LoginApi#login] content-type: application/json;charset=utf-8】 feign.Logger(58) [http-nio-8080-exec-1] []

v_1.4.0  INFO 2020-06-13 15:59:03 【[LoginApi#login] date: Sat, 13 Jun 2020 07:59:03 GMT】 feign.Logger(58) [http-nio-8080-exec-1] []

v_1.4.0  INFO 2020-06-13 15:59:03 【[LoginApi#login] transfer-encoding: chunked】 feign.Logger(58) [http-nio-8080-exec-1] []

v_1.4.0  INFO 2020-06-13 15:59:03 【[LoginApi#login] 】 feign.Logger(58) [http-nio-8080-exec-1] []

v_1.4.0  INFO 2020-06-13 15:59:03 【[LoginApi#login] {"success":true,"code":200,"msg":"SUCCESS","details":null,"ex":null,"data":{"registTime":1591933549000,"contractPhone":"13433335555","country":1754,"isLogout":0,"emailAddress":"678882609@qq.com","password":"d7861c1594ddd737a663edd75d029f24","createTime":1591933549000,"nickName":"cl","companyName":"maclstudio","id":2006121145491216,"userName":"tomy","token":"b8e5d3a9-f6ff-44d1-bcf2-8de1526ab3sdddd"}}】 feign.Logger(58) [http-nio-8080-exec-1] []

v_1.4.0  INFO 2020-06-13 15:59:03 【[LoginApi#login] <--- END HTTP (397-byte body)】 feign.Logger(58) [http-nio-8080-exec-1] []