SpringCloud之服務提供與調用(Ribbon,Feign)

時間 2019-11-05

標籤 springcloud 服務提供調用 ribbon feign 简体版

原文原文鏈接

本系列介紹的配置均基於 Spring Boot 2.0.1.RELEASE 版本和 Spring Cloud Finchley.SR1git

eureka註冊續約流程

啓動註冊中心
服務提供者生產服務並註冊到服務中心中
消費者從服務中心中獲取服務並執行

服務提供

1.在spring-cloud-manage下建立一個子項目producer-service

pom.xml文件以下github

<?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">
    <parent>
        <artifactId>spring-cloud-manage</artifactId>
        <groupId>org.springcloudmanage</groupId>
        <version>1.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>producer-service</artifactId>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </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-netflix-eureka-client</artifactId>
        </dependency>
    </dependencies>

    <build>
        <finalName>producer-service</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

2.建立啓動類

Finchley版本已經不須要添加@EnableDiscoveryClient註解,Spring Cloud會自動識別。web

@SpringBootApplication
public class ProducerServiceApplication {

    public static void main(String[] args) {
        SpringApplication.run(ProducerServiceApplication.class, args);
    }

}

3.配置文件

spring.application.name=producer-service
server.port=9001
#eureka
eureka.client.serviceUrl.defaultZone=http://localhost:8001/eureka/

spring.application.name 服務提供者的名字
server.por 服務端口號
eureka.client.serviceUrl.defaultZone eureka的服務註冊地址，若是eureka是多節點，多個地址逗號分隔，具體能夠看上一篇博客:服務註冊與發現。

多節點eureka服務註冊以下：spring

eureka.client.serviceUrl.defaultZone=http://localhost:8001/eureka/,http://localhost:8002/eureka/

4.Action or Controller類

@RestController
@RequestMapping(value = "/test")
public class ProducerAction {

    @RequestMapping(value = "", method = RequestMethod.GET)
    public String test(String param) {
        return "param is " + param;
    }

}

5.啓動服務

服務啓動後，訪問eureka主頁http://localhost:8001/，便可看到以下頁面，說明服務已經註冊到eureka上了 apache

6.調用下試試

訪問http://localhost:9001/test?param=test，看到返回結果以下app

param is test

服務消費 ribbon

Ribbon 了，它是一個基於 HTTP 和 TCP 的客戶端負載均衡器。它能夠經過在客戶端中配置ribbonServerList 來設置服務端列表去輪詢訪問以達到均衡負載的做用。負載均衡

當 Ribbon 與 Eureka聯合使用時，ribbonServerList會被DiscoveryEnabledNIWSServerList 重寫，擴展成從 Eureka 註冊中心中獲取服務實例列表。同時它也會用 NIWSDiscoveryPing 來取代 IPing，它將職責委託給 Eureka 來肯定服務端是否已經啓動。maven

1.在spring-cloud-manage下建立一個子項目consumer-service

pom.xml文件以下ide

<?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">
    <parent>
        <artifactId>spring-cloud-manage</artifactId>
        <groupId>org.springcloudmanage</groupId>
        <version>1.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>consumer-service</artifactId>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </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-netflix-eureka-client</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

spring-cloud-starter-netflix-eureka-client中已經引用了ribbon先關的jar，所需不須要再引入了spring-boot

2.建立啓動類

@SpringBootApplication
public class ConsumerServiceApplication {

    @LoadBalanced
    @Bean
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }

    public static void main(String[] args) {
        SpringApplication.run(ConsumerServiceApplication.class, args);
    }

}

3.配置文件

spring.application.name=consumer-service
server.port=9002
#eureka
eureka.client.serviceUrl.defaultZone=http://localhost:8001/eureka/

4.Action or Controller類

這裏注入restTemplate，Spring Cloud Ribbon 本身有攔截器會對服務名producer-service作解析，自動的去選取服務實例負載均衡調用，並將服務名替換成實際要請求的IP地址和端口

@RestController
@RequestMapping(value = "/ribbon/test")
public class ConsumerAction {

    @Autowired
    private RestTemplate restTemplate;

    @RequestMapping(value = "", method = RequestMethod.GET)
    public String test(String param) {
        String url = "http://producer-service/test/?param=" + param;
        return restTemplate.getForObject(url, String.class);
    }
    
}

5.啓動服務

消費端服務啓動成功後，能夠看到erueka時已經顯示註冊成功了

5.調用消費端服務

訪問http://localhost:9002/ribbon/test?param=ribbon-test ,能夠看到以下結果，說明消費端服務接收到參數後，經過ribbon負載均衡，調用到producer-service的接口。

param is ribbon-test

控制檯日誌

2018-08-28 16:25:23.397  INFO 3791 --- [nio-9002-exec-1] c.netflix.config.ChainedDynamicProperty  : Flipping property: producer-service.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647
2018-08-28 16:25:23.414  INFO 3791 --- [nio-9002-exec-1] c.n.u.concurrent.ShutdownEnabledTimer    : Shutdown hook installed for: NFLoadBalancer-PingTimer-producer-service
2018-08-28 16:25:23.433  INFO 3791 --- [nio-9002-exec-1] c.netflix.loadbalancer.BaseLoadBalancer  : Client: producer-service instantiated a LoadBalancer: DynamicServerListLoadBalancer:{NFLoadBalancer:name=producer-service,current list of Servers=[],Load balancer stats=Zone stats: {},Server stats: []}ServerList:null
2018-08-28 16:25:23.440  INFO 3791 --- [nio-9002-exec-1] c.n.l.DynamicServerListLoadBalancer      : Using serverListUpdater PollingServerListUpdater
2018-08-28 16:25:23.462  INFO 3791 --- [nio-9002-exec-1] c.netflix.config.ChainedDynamicProperty  : Flipping property: producer-service.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647
2018-08-28 16:25:23.463  INFO 3791 --- [nio-9002-exec-1] c.n.l.DynamicServerListLoadBalancer      : DynamicServerListLoadBalancer for client producer-service initialized: DynamicServerListLoadBalancer:{NFLoadBalancer:name=producer-service,current list of Servers=[192.168.101.238:9001],Load balancer stats=Zone stats: {defaultzone=[Zone:defaultzone;	Instance count:1;	Active connections count: 0;	Circuit breaker tripped count: 0;	Active connections per server: 0.0;]
},Server stats: [[Server:192.168.101.238:9001;	Zone:defaultZone;	Total Requests:0;	Successive connection failure:0;	Total blackout seconds:0;	Last connection made:Thu Jan 01 08:00:00 CST 1970;	First connection made: Thu Jan 01 08:00:00 CST 1970;	Active Connections:0;	total failure count in last (1000) msecs:0;	average resp time:0.0;	90 percentile resp time:0.0;	95 percentile resp time:0.0;	min resp time:0.0;	max resp time:0.0;	stddev resp time:0.0]
]}ServerList:org.springframework.cloud.netflix.ribbon.eureka.DomainExtractingServerList@12e48993
2018-08-28 16:25:24.447  INFO 3791 --- [erListUpdater-0] c.netflix.config.ChainedDynamicProperty  : Flipping property: producer-service.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647

能夠啓動多個producer-service服務測試下實際的負載均衡效果。

服務消費 feign

Feign是一個聲明式的Web Service客戶端，它使得編寫Web Serivce客戶端變得更加簡單。咱們只須要使用Feign來建立一個接口並用註解來配置它既可完成。它具有可插拔的註解支持，包括Feign註解和JAX-RS註解。Feign也支持可插拔的編碼和解碼。Spring Cloud爲Feign增長了對Spring MVC註解的支持，還整合了Ribbon和Eureka來提供均衡負載的HTTP客戶端實現。

在實際工做中，咱們基本上都是使用Feign來完成調用的。咱們經過一個例子來展示 Feign 如何方便的聲明對 eureka-producer 服務的定義和調用。

1.consumer-service添加對feign的依賴

<?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">
    <parent>
        <artifactId>spring-cloud-manage</artifactId>
        <groupId>org.springcloudmanage</groupId>
        <version>1.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>consumer-service</artifactId>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </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-openfeign</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

2.啓動類上加上feign所需註解

@EnableFeignClients
@SpringBootApplication
public class ConsumerServiceApplication {

    public static void main(String[] args) {
        SpringApplication.run(ConsumerServiceApplication.class, args);
    }

}

3.配置文件

spring.application.name=consumer-service
server.port=9002
#eureka
eureka.client.serviceUrl.defaultZone=http://localhost:8001/eureka/
#開啓Hystrix斷路器
feign.hystrix.enabled=true
#斷路器的超時時間須要大於ribbon的超時時間，否則不會觸發重試,缺省爲1000
hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds=5000

4.feign 調用

建立feign客戶端調用類，其中name爲所需調用的服務名，fallback使用Hystrix，當producer-service不可用時，對服務作降級，並返回友好提示

@FeignClient(name = "producer-service", fallback = ProducerServiceFeignClientHystrix.class)
public interface ProducerServiceFeignClient {

    @RequestMapping(value = "/test", method = RequestMethod.GET)
    String test(@RequestParam("param") String param);

}

==注意@RequestParam("param")中name必需要和producer-service服務中的參數名一致==

@Component
public class ProducerServiceFeignClientHystrix implements ProducerServiceFeignClient {
    @Override
    public String test(String param) {
        return "服務[producer-service]沒法訪問";
    }
}

訪問http://localhost:9002/feign/test?param=feign-test，能夠看到以下結果