SpringCloud分散式微服務b2b2c電子商務docker-feign配置（六）

這節我們討論一下feign配置，透過編寫配置類，我們可以自定義feign的日誌級別，日誌掃描目錄，可以透過feign呼叫服務在eureka上的呼叫資訊。

feign宣告介面之後，在程式碼中透過@Resource或者@Autowired注入之後即可使用。

@FeignClient標籤的常用屬性如下：

name：指定FeignClient的名稱，如果專案使用了Ribbon，name屬性會作為微服務的名稱，用於服務發現瞭解springcloud架構可以加求求：三五三六二四七二五九

url: url一般用於除錯，可以手動指定@FeignClient呼叫的地址

decode404:當發生http 404錯誤時，如果該欄位位true，會呼叫decoder進行解碼，否則丟擲FeignException

configuration: Feign配置類，可以自定義Feign的Encoder、Decoder、LogLevel、Contract

fallback: 定義容錯的處理類，當呼叫遠端介面失敗或超時時，會呼叫對應介面的容錯邏輯，fallback指定的類必須實現@FeignClient標記的介面

fallbackFactory: 工廠類，用於生成fallback類示例，透過這個屬性我們可以實現每個介面通用的容錯邏輯，減少重複的程式碼

path: 定義當前FeignClient的統一字首

一、建立模組（microservice-consumer-movie-feign-customizing）

專案結構如下：

二、pom.xml檔案

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="
         xmlns:xsi="
         xsi:schemaLocation="
    <parent>
        <artifactId>microservice-spring-cloud</artifactId>
        <groupId>com.jacky</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>microservice-consumer-movie-feign-customizing</artifactId>
    <packaging>jar</packaging>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-feign</artifactId>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>com.spotify</groupId>
                <artifactId>docker-maven-plugin</artifactId>
                <executions>
                    <!--設定在執行maven 的install時構建映象-->
                    <execution>
                        <id>build-image</id>
                        <phase>install</phase>
                        <goals>
                            <goal>build</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <!--安裝了docker的主機，並且開啟了api remote介面設定-->
                    <dockerHost>http://192.168.6.130:5678</dockerHost>
                    <pushImage>true</pushImage><!--設定上傳映象到私有倉庫，需要docker設定指定私有倉庫地址-->
                    <!--映象名稱-->
                    <imageName>${docker.repostory}/${docker.image.prefix}/${project.artifactId}:${project.version}</imageName>
                    <!--映象的基礎版本-->
                    <baseImage>java:openjdk-8-jdk-alpine</baseImage>
                    <!--映象啟動引數-->
                    <entryPoint>["java", "-jar", "/${project.build.finalName}.jar"]</entryPoint>
                    <resources>
                        <resource>
                            <targetPath>/</targetPath>
                            <directory>${project.build.directory}</directory>
                            <include>${project.build.finalName}.jar</include>
                        </resource>
                    </resources>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

三、配置檔案

spring:
  application:
    name: microservice-consumer-movie-feign-customizing
server:
  port: 7901
eureka:
  client:
    healthcheck:
      enabled: true
    serviceUrl:
      defaultZone: 
  instance:
    prefer-ip-address: true
#feign日誌配置
logging:
  level:
    com.jacky.cloud.feign.UserFeignClient: DEBUG
# 解決第一次請求報超時異常的方案：
# hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds: 5000  #延長超時時間
# 或者：
# hystrix.command.default.execution.timeout.enabled: false
# 或者：
feign.hystrix.enabled: false                       # 索性禁用feign的hystrix支援
# 超時的issue：
# 超時的解決方案： 
# hystrix配置： https://github.com/Netflix/Hystrix/wiki/Configuration#execution.isolation.thread.timeoutInMilliseconds

四、實體類User.java

package com.jacky.cloud.entity;
import java.math.BigDecimal;
public class User {
  private Long id;
  private String username;
  private String name;
  private Short age;
  private BigDecimal balance;
  public Long getId() {
    return this.id;
  }
  public void setId(Long id) {
    this.id = id;
  }
  public String getUsername() {
    return this.username;
  }
  public void setUsername(String username) {
    this.username = username;
  }
  public String getName() {
    return this.name;
  }
  public void setName(String name) {
    this.name = name;
  }
  public Short getAge() {
    return this.age;
  }
  public void setAge(Short age) {
    this.age = age;
  }
  public BigDecimal getBalance() {
    return this.balance;
  }
  public void setBalance(BigDecimal balance) {
    this.balance = balance;
  }
}

五、feign客戶端1（UserFeignClient1.java）

package com.jacky.cloud.feign;
import org.springframework.cloud.netflix.feign.FeignClient;
import com.jacky.cloud.entity.User;
import com.jacky.config.Configuration1;
import feign.Param;
import feign.RequestLine;
@FeignClient(name = "microservice-provider-user", configuration = Configuration1.class)
public interface UserFeignClient1 {
  @RequestLine("GET /simple/{id}")
  public User findById(@Param("id") Long id);
}

六、feign客戶端2（UserFeignClient2.java）

package com.jacky.cloud.feign;
import org.springframework.cloud.netflix.feign.FeignClient;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import com.jacky.config.Configuration2;
@FeignClient(name = "xxxx", url = ")
public interface UserFeignClient2 {
  @RequestMapping(value = "/eureka/apps/{serviceName}")
  public String findServiceInfoFromEurekaByServiceName(@PathVariable("serviceName") String serviceName);
}

七、feign配置類1（Configuration1.java）

package com.jacky.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import feign.Contract;
import feign.Logger;
@Configuration
public class Configuration1 {
  @Bean
  public Contract feignContract() {
    return new feign.Contract.Default();
  }
  @Bean
  Logger.Level feignLoggerLevel() {
    return Logger.Level.FULL;  //定義feign日誌顯示級別
  }
}

八、feign配置類2（Configuration2.java）

package com.jacky.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import feign.auth.BasicAuthRequestInterceptor;
@Configuration
public class Configuration2 {
  @Bean
  public BasicAuthRequestInterceptor basicAuthRequestInterceptor() {
    return new BasicAuthRequestInterceptor("jacky", "admin"); //Eureka新增了安全驗證，則需要配置上面的使用者名稱、密碼
  }
}

九、MovieController.java

package com.jacky.cloud.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import com.jacky.cloud.entity.User;
import com.jacky.cloud.feign.UserFeignClient2;
import com.jacky.cloud.feign.UserFeignClient1;
@RestController
public class MovieController {
  @Autowired
  private UserFeignClient1 userFeignClient1;
  @Autowired
  private UserFeignClient2 userfeignClient2;
  /**
   * 呼叫生產者服務
   * @param id
   * @return
     */
  @GetMapping("/movie/{id}")
  public User findById(@PathVariable Long id) {
    return this.userFeignClient1.findById(id);
  }
  /**
   * 獲得服務在eureka資訊
   * @param serviceName
   * @return
     */
  @GetMapping("/{serviceName}")
  public String findServiceInfoFromEurekaByServiceName(@PathVariable String serviceName) {
    return this.userfeignClient2.findServiceInfoFromEurekaByServiceName(serviceName);
  }
}

十、啟動類ConsumerMovieFeignApplication.java

package com.jacky.cloud;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.feign.EnableFeignClients;
@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients
public class ConsumerMovieFeignApplication {
  public static void main(String[] args) {
    SpringApplication.run(ConsumerMovieFeignApplication.class, args);
  }
}