maven依赖

<!--okhttp-->
<dependency>
    <groupId>com.squareup.okhttp3</groupId>
    <artifactId>okhttp</artifactId>
    <!--版本从springboot-parent继承-->
</dependency>
<dependency>
    <groupId>io.github.openfeign</groupId>
    <artifactId>feign-okhttp</artifactId>
    <!--与openfeign版本一致-->
    <version>10.12</version>
</dependency>

yml配置

# feign 使用okhttp客户端
feign:
  httpclient:
    enabled: false
  okhttp:
    enabled: true

feign配置类

package com.jyx.warmhs.config;

import com.jyx.warmhs.interceptor.FeignExceptionInterceptor;
import feign.Feign;
import okhttp3.ConnectionPool;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.cloud.commons.httpclient.OkHttpClientConnectionPoolFactory;
import org.springframework.cloud.commons.httpclient.OkHttpClientFactory;
import org.springframework.cloud.openfeign.FeignAutoConfiguration;
import org.springframework.cloud.openfeign.support.FeignHttpClientProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.annotation.PreDestroy;
import javax.annotation.Resource;
import java.util.concurrent.TimeUnit;

/**
 * 配置feign使用okhttp客户端，从而支持feign请求拦截
 * @author cdh
 */
@Configuration
@ConditionalOnClass(Feign.class)
@AutoConfigureAfter(FeignAutoConfiguration.class)
public class FeignOkHttpConfig {

    @Resource
    FeignExceptionInterceptor feignExceptionInterceptor;
    private okhttp3.OkHttpClient okHttpClient;

    @Bean
    public ConnectionPool httpClientConnectionPool(FeignHttpClientProperties httpClientProperties, OkHttpClientConnectionPoolFactory connectionPoolFactory) {
        Integer maxTotalConnections = httpClientProperties.getMaxConnections();
        Long timeToLive = httpClientProperties.getTimeToLive();
        TimeUnit ttlUnit = httpClientProperties.getTimeToLiveUnit();
        return connectionPoolFactory.create(maxTotalConnections, timeToLive, ttlUnit);
    }

    @Bean
    public okhttp3.OkHttpClient client(OkHttpClientFactory httpClientFactory, ConnectionPool connectionPool, FeignHttpClientProperties httpClientProperties) {
        Boolean followRedirects = httpClientProperties.isFollowRedirects();
        Integer connectTimeout = httpClientProperties.getConnectionTimeout();
        Boolean disableSslValidation = httpClientProperties.isDisableSslValidation();
        this.okHttpClient = httpClientFactory.createBuilder(disableSslValidation)
                .connectTimeout((long)connectTimeout, TimeUnit.MILLISECONDS)
                .followRedirects(followRedirects)
                .connectionPool(connectionPool)
                // feign异常处理拦截器
                .addInterceptor(feignExceptionInterceptor)
                .build();
        return this.okHttpClient;
    }

    @PreDestroy
    public void destroy() {
        if (this.okHttpClient != null) {
            this.okHttpClient.dispatcher().executorService().shutdown();
            this.okHttpClient.connectionPool().evictAll();
        }
    }
}

拦截器

package com.jyx.warmhs.interceptor;


import okhttp3.Interceptor;
import okhttp3.Request;
import okhttp3.Response;
import org.springframework.stereotype.Component;

import java.io.IOException;

/**
 * @author huazai
 * @date 2021/07/23
 */
@Component
public class FeignExceptionInterceptor implements Interceptor {

    @Override
    public Response intercept(Chain chain) throws IOException {
        Request request=chain.request();
        Response response = chain.proceed(request);
        String body = response.body().string();
        System.out.println(body);
        return response;
    }
}