SpringCloud组件二之Ribbon-消费者（G版本）

1.服务消费

在上一篇文章，讲明了服务的注册和发现。这一篇我们讲如何去消费服务，在Spring cloud有两种服务调用方式，一种是ribbon，另一种是feign。在这一篇先进行对Ribbon的讲解。

2.目前现状

我们有一个注册中心（resitry），一个服务提供者（provider），provider中编写一个接口/hello

@RestController
public class TsetController {

    @GetMapping("hello")
    public String hello(){
        return "hello";
    }
}

           

3. 新建服务（Ribbon）

• POM文件

<?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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>cn.lll</groupId>
    <artifactId>ribbon</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>ribbon</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.SR1</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

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

</project>

           

• 添加注释

@SpringBootApplication
@EnableEurekaClient
public class RibbonApplication {

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

}
           

• 配置yml文件

server:
  port: 8082

spring:
  application:
    name: ribbon-server

eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:10010/eureka
           

4.注入RestTeplate

@SpringBootApplication
@EnableEurekaClient
public class RibbonApplication {

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

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

}
           

@RestController
public class TestController {

    @Autowired
    private RestTemplate restTemplate;

    @GetMapping("hello")
    public String hello(){
        return restTemplate.getForObject("http://SERVER-PROVIDER/hello",String.class);
    }
}

           

5.Ribbon的负载均衡功能

@Bean
    @LoadBalanced //Ribbon具有负载均衡的功能,添加该注解表示开启，默认为轮询
    RestTemplate restTemplate() {
        return new RestTemplate();
    }