Spring Cloud Feign高階應用例項詳解

阿新 • • 發佈：2020-01-09

這篇文章主要介紹了Spring Cloud Feign高階應用例項詳解,文中通過示例程式碼介紹的非常詳細，對大家的學習或者工作具有一定的參考學習價值,需要的朋友可以參考下

1.使用feign進行服務間的呼叫

Spring boot2X Consul如何使用Feign實現服務呼叫

2.開啟gzip壓縮

Feign支援對請求與響應的壓縮，以提高通訊效率，需要在服務消費者配置檔案開啟壓縮支援和壓縮檔案的型別

新增配置

feign.compression.request.enabled=true
feign.compression.response.enabled=true
feign.compression.request.mime-types=text/xml,application/xml,application/json
feign.compression.request.min-request-size=2048

3.開啟日誌

配置

logging.level.com.xyz.comsumer.feign.RemoteHelloService=debug

新增FeignLogConfig類

package com.xyz.comsumer.configure;

import feign.Logger;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class FeignLogConfig {
  @Bean
  Logger.Level feignLogger(){
    return Logger.Level.FULL;
  }
}

輸出

2019-12-07 23:23:03.630 DEBUG 2668 --- [vice-provider-1] c.xyz.comsumer.feign.RemoteHelloService : [RemoteHelloService#hello] <--- HTTP/1.1 200 (671ms)
2019-12-07 23:23:03.631 DEBUG 2668 --- [vice-provider-1] c.xyz.comsumer.feign.RemoteHelloService : [RemoteHelloService#hello] content-length: 14
2019-12-07 23:23:03.631 DEBUG 2668 --- [vice-provider-1] c.xyz.comsumer.feign.RemoteHelloService : [RemoteHelloService#hello] content-type: text/plain;charset=UTF-8
2019-12-07 23:23:03.631 DEBUG 2668 --- [vice-provider-1] c.xyz.comsumer.feign.RemoteHelloService : [RemoteHelloService#hello] date: Sat,07 Dec 2019 15:23:03 GMT
2019-12-07 23:23:03.631 DEBUG 2668 --- [vice-provider-1] c.xyz.comsumer.feign.RemoteHelloService : [RemoteHelloService#hello] vary: Origin
2019-12-07 23:23:03.631 DEBUG 2668 --- [vice-provider-1] c.xyz.comsumer.feign.RemoteHelloService : [RemoteHelloService#hello] vary: Access-Control-Request-Method
2019-12-07 23:23:03.631 DEBUG 2668 --- [vice-provider-1] c.xyz.comsumer.feign.RemoteHelloService : [RemoteHelloService#hello] vary: Access-Control-Request-Headers
2019-12-07 23:23:03.631 DEBUG 2668 --- [vice-provider-1] c.xyz.comsumer.feign.RemoteHelloService : [RemoteHelloService#hello] 
2019-12-07 23:23:03.632 DEBUG 2668 --- [vice-provider-1] c.xyz.comsumer.feign.RemoteHelloService : [RemoteHelloService#hello] hello,provider
2019-12-07 23:23:03.632 DEBUG 2668 --- [vice-provider-1] c.xyz.comsumer.feign.RemoteHelloService : [RemoteHelloService#hello] <--- END HTTP (14-byte body)

說明：

　　Feign日誌記錄只能響應DEBUG日誌級別

對每一個Feign客戶端，可以配置一個Logger.Level物件，通過該物件控制日誌輸出內容。

Logger.Level有如下幾種選擇：

NONE,不記錄日誌 (預設)。

BASIC,只記錄請求方法和URL以及響應狀態程式碼和執行時間。

HEADERS,記錄請求和應答的頭的基本資訊。

FULL,記錄請求和響應的頭資訊，正文和元資料。

4.替換JDK預設的URLConnection為okhttp

在預設情況下 spring cloud feign在進行各個子服務之間的呼叫時，http元件使用的是jdk的HttpURLConnection

服務之間呼叫使用的HttpURLConnection，效率非常低

為了提高效率，可以通過連線池提高效率

使用okhttp，能提高qps，因為okhttp有連線池和超時時間進行調優

新增依賴

<dependency>
  <groupId>io.github.openfeign</groupId>
  <artifactId>feign-okhttp</artifactId>
</dependency>

修改配置

禁用預設的http，啟用okhttp

feign.okhttp.enabled=true
feign.httpclient.enabled=false

新增FeignOkHttpConfig類

package com.xyz.comsumer.configure;

import feign.Feign;
import okhttp3.ConnectionPool;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.AutoConfigureBefore;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.cloud.openfeign.FeignAutoConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.concurrent.TimeUnit;

@Configuration
@ConditionalOnClass(Feign.class)
@AutoConfigureBefore(FeignAutoConfiguration.class)
public class FeignOkHttpConfig {

  @Bean
  public okhttp3.OkHttpClient okHttpClient(){
    return new okhttp3.OkHttpClient.Builder()
        .readTimeout(10,TimeUnit.SECONDS)
        .connectTimeout(10,TimeUnit.SECONDS)
        .writeTimeout(20,TimeUnit.SECONDS)
        .retryOnConnectionFailure(true)
        .connectionPool(new ConnectionPool())
        .build();
  }
}

5.超時設定

Feign呼叫服務的預設時長是1秒鐘

hystrix的超時時間

hystrix.command.default.execution.timeout.enabled=true
hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds=10000

說明：

　　hystrix.command.default.execution.timeout.enabled 執行是否啟用超時，預設啟用true

　　hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds 命令執行超時時間，預設1000ms

　　常用的配置還有

　　　　hystrix.command.default.execution.isolation.strategy 隔離策略，預設是Thread,可選THREAD｜SEMAPHORE，建議選擇SEMAPHORE

Feign 的負載均衡底層用的就是 Ribbon

ribbon的超時時間

ribbon.ReadTimeout=10000
ribbon.ConnectTimeout=10000

6.使用hystrix進行熔斷、降級處理

feign啟用hystrix，才能熔斷、降級

feign.hystrix.enabled=true

hystrix服務降級處理

RemoteHelloServiceFallbackImpl

package com.xyz.comsumer.feign.fallback;

import com.xyz.comsumer.feign.RemoteHelloService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

@Component
public class RemoteHelloServiceFallbackImpl implements RemoteHelloService {
  private final Logger logger = LoggerFactory.getLogger(RemoteHelloServiceFallbackImpl.class);

  @Override
  public String hello() {
    logger.error("feign 查詢資訊失敗:{}");
    return null;
  }
}

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支援我們。