重寫Feign+單個禁用Feign的Hystrix支援

如果Hystrix在類路徑和feign上hystrix。

啟用= true,Feign將用一個斷路器來包裝所有的方法。

返回一個com.netflix.hystrix.HystrixCommand也是可用的。

這允許您使用反應模式(呼叫. toobservable()或. observe()或非同步使用(呼叫. queue())。

要在每個客戶機基礎上禁用Hystrix支援，可以建立一個香草假。使用“原型”範圍的構建器，例如:

ConfigurationAuth類

package com.example.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Scope;

import feign.Feign;
import feign.auth.BasicAuthRequestInterceptor;

/**
 * 此類不要放在啟動類能掃描到的包下
 * @author 重寫Feign的預設配置
 *
 */
@Configuration
public class ConfigurationAuth {
		//配置註冊到Eureka所需要的賬戶和密碼
	  @Bean
	  public BasicAuthRequestInterceptor basicAuthRequestInterceptor() {
	    return new BasicAuthRequestInterceptor("user", "123456");
	  }
	  
	  /**
	   * 禁用單個feign的hystrix支援
	   * @return
	   */
	  @Bean
	  @Scope("prototype")
	  public Feign.Builder feignBuilder() {
	    return Feign.builder();
	  }
}
 

ConfigurationContract類

package com.example.config;

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

import feign.Contract;
import feign.Logger;

/**
 * 此類不要放在啟動類能掃描到的包下
 * @author 重寫Feign的預設配置
 *
 */
@Configuration
public class ConfigurationContract {
	 //Contract預設是Spring MVC的契約，就可以用Spring MVC的註解
	  @Bean
	  public Contract feignContract() {
	    return new feign.Contract.Default();
	  }
	  
	  //配置日誌級別
	  @Bean
	  Logger.Level feignLoggerLevel() {
	    return Logger.Level.FULL;
	  }
}
 

OrderController類

package com.example.demo.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.example.demo.entity.User;
import com.example.demo.feign.FeignClientServiceName;
import com.example.demo.feign.UserFeignClient;

//宣告式服務
@RestController
public class OrderController {
		
	  @Autowired
	  private UserFeignClient userFeignClient;
	  
	  @Autowired
	  private FeignClientServiceName feignClientServiceName;  

	  @GetMapping("/order/{id}")
	  public User findById(@PathVariable Long id) {
	    return this.userFeignClient.findById(id);
	  }

	  @GetMapping("/{serviceName}")
	  public String findServiceInfoFromEurekaByServiceName(@PathVariable String serviceName) {
	    return this.feignClientServiceName.findServiceInfoFromEurekaByServiceName(serviceName);
	  }
}
 

User類

package com.example.demo.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;
  }

}

FeignClientServiceHystrixFeignFallBack類

package com.example.demo.feign;

 

import org.springframework.stereotype.Component;

 

@Component

public class FeignClientServiceHystrixFeignFallBack implements FeignClientServiceName {

 

@Override

public String findServiceInfoFromEurekaByServiceName(String serviceName) {

return "hello";

}

 

}

FeignClientServiceName介面

package com.example.demo.feign;

import org.springframework.cloud.netflix.feign.FeignClient;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;

import com.example.config.ConfigurationAuth;

@FeignClient(name = "aaaa", url = "http://localhost:8761/", configuration = ConfigurationAuth.class,fallback=FeignClientServiceHystrixFeignFallBack.class)
public interface FeignClientServiceName {
  @RequestMapping(value = "/eureka/apps/{serviceName}")
  public String findServiceInfoFromEurekaByServiceName(@PathVariable("serviceName") String serviceName);
}

UserFeignClient介面

package com.example.demo.feign;

import org.springframework.cloud.netflix.feign.FeignClient;

import com.example.config.ConfigurationContract;
import com.example.demo.entity.User;

import feign.Param;
import feign.RequestLine;

//重寫Feign的預設配置
@FeignClient(name = "spring-cloud-user", configuration = ConfigurationContract.class,fallback=UserHystrixFeignFallBack.class) // 呼叫哪個服務的名稱
public interface UserFeignClient {
	
	  @RequestLine("GET /user/{id}") //注意：GET後面有一個空格
	  public User findById(@Param("id") Long id);

UserHystrixFeignFallBack類

package com.example.demo.feign;

import org.springframework.stereotype.Component;

import com.example.demo.entity.User;

@Component
public class UserHystrixFeignFallBack implements UserFeignClient {

	@Override
	public User findById(Long id) {
		return new User();
	}

}

SpringCloudOrderApplication類

package com.example.demo;

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;

/**
 * 宣告式服務
 *
 */

@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients//表示為Fegin客戶端
public class SpringCloudOrderApplication {
	
	public static void main(String[] args) {
		SpringApplication.run(SpringCloudOrderApplication.class, args);
	}
}

application.yml配置

spring:
  application:
    name: spring-cloud-order_overriding_feign_defaults-hystrix    #微服務的名稱
server:
  port: 7907  #微服務埠號
eureka:
  client:
    healthcheck: 
      enabled: true   # 開啟健康檢查
    serviceUrl:
      defaultZone: http://user:[email protected]:8761/eureka   #服務eureka的URL地址
  instance:
    prefer-ip-address: true
logging:
  level:
    com.example.demo.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
# 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：https://github.com/spring-cloud/spring-cloud-netflix/issues/768
# 超時的解決方案： http://stackoverflow.com/questions/27375557/hystrix-command-fails-with-timed-out-and-no-fallback-available
# hystrix配置： https://github.com/Netflix/Hystrix/wiki/Configuration#execution.isolation.thread.timeoutInMilliseconds

pom.xml配置

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>com.example.demo</groupId>
	<artifactId>spring-cloud-order_overriding_feign_defaults</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>war</packaging>

	<name>spring-cloud-order_overriding_feign_defaults</name>
	<description>spring-cloud-order_overriding_feign_defaults</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.4.1.RELEASE</version>
	</parent>

	<properties>
		<!-- 檔案拷貝時的編碼 -->  
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		  <!-- 編譯時的編碼 -->  
        <maven.compiler.encoding>UTF-8</maven.compiler.encoding>  
        <!-- jdk版本 -->  
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		<!-- 註冊中心 -->
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-eureka</artifactId>
		</dependency>
		<!-- 這個庫讓我們可以訪問應用的很多資訊,包括:/env、/info、/metrics、/health等 -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-actuator</artifactId>
		</dependency>
		<!-- 新增宣告式feign依賴 -->
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-feign</artifactId>
		</dependency>
		
		<!-- 用於熱部署 -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-devtools</artifactId>
		</dependency>		
	</dependencies>
	<dependencyManagement>
		<dependencies>
		<!-- 版本依賴管理，故之後新增依賴無需指定version -->
			<dependency>
				<groupId>org.springframework.cloud</groupId>
				<artifactId>spring-cloud-dependencies</artifactId>
				<version>Camden.SR2</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
		</dependencies>
	</dependencyManagement>

	<build>
		<plugins>
		<!-- 用以為integration-test提供支援。 -->
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>
</project>

把使用者服務停掉之後，效果如下：

檢視健康指標：hystrix起作用了