SpringCloud个人笔记-02-Feign初体验

• 项目结构

• sb_cloud_product

<?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.huarui</groupId>
    <artifactId>sb_cloud_product</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>sb_cloud_product</name>
    <description>Demo project for Spring Boot</description>
 
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.13.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
 
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <spring-cloud.version>Edgware.SR3</spring-cloud.version>
    </properties>
 
    <dependencies>
 
        <!-- eureka client -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>
 
        <!-- ribbon依赖 -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-ribbon</artifactId>
        </dependency>
 
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </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>

pom.xml

server:
  port: 9000
 
spring:
  application:
    name: sb-cloud-product
 
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/

application.yml

@SpringBootApplication
@EnableDiscoveryClient //开启服务注册
@EnableFeignClients　　 //开启Feign
public class SbCloudProductApplication {

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

---

• sb_cloud_order

<?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.huarui</groupId>
    <artifactId>sb_cloud_order</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>sb_cloud_order</name>
    <description>Demo project for Spring Boot</description>
 
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.13.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
 
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <spring-cloud.version>Edgware.SR3</spring-cloud.version>
    </properties>
 
    <dependencies>
 
        <!-- eureka client -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>
 
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-feign</artifactId>
        </dependency>
 
        <!-- ribbon依赖 -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-ribbon</artifactId>
        </dependency>
 
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </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>

pom.xml

server:
  port: 9001
 
spring:
  application:
    name: sb-cloud-order
 
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/

application.yml

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

@FeignClient(name = "sb-cloud-product")
public interface ProductRemote {
 
    /**
     * name:远程服务名，即spring.application.name配置的名称
     *类中的方法和远程服务中contoller中的方法名和参数需保持一致
     *
     * @return
     */
 
    @GetMapping(value = "/product/getMsg")
    public Map<String,String> getMsg();
}

• RestTemplate三种访问服务端口接口方法

@RestController
@RequestMapping("/order")
public class OrderCtrl {

    @Autowired
    private LoadBalancerClient loadBalancerClient;

    @Autowired
    private RestTemplate restTemplate2;

    @Autowired
    private ProductRemote productRemote;

    /**
     *  RestTemplate 三种使用方式
     * @return
     */
    @RequestMapping("/getProduct")
    public Map<String,String> getProduct(){

        //http://localhost:9000/product/getMsg

        RestTemplate restTemplate = new RestTemplate();
        //1.第一种方式(直接通过地址访问)
        //Map<String,String> map = restTemplate.getForObject("http://localhost:9000/product/getMsg", Map.class);

        //2.第二种方式(利用loadBalancerClient通过应用名获取url)
        /*ServiceInstance serviceInstance = loadBalancerClient.choose("sb-cloud-product");
        String url = String.format("http://%s:%s", serviceInstance.getHost(), serviceInstance.getPort() + "/product/getMsg");
        Map<String,String> map = restTemplate.getForObject(url, Map.class);*/

        //3.第三种方式(通过@LoadBalanced注解让restTemplate获得负载均衡能力 访问接口时使用应用名字)
        Map<String,String> map = restTemplate2.getForObject("http://sb-cloud-product:9000/product/getMsg", Map.class);

        return map;

    }

　　/* 通过feign 远程访问sb_cloud_product 服务 */
    @GetMapping("/feign/getProduct")
    public Map<String,String> feignGetProduct(){
        return productRemote.getMsg();
    }

}