1、Feigin接口： ProductClientService

import com.mengxuegu.springcloud.entities.Product;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import java.util.List;


@FeignClient(value = "microservice-product") //指定调用的微服务名称
public interface ProductClientService {
    @RequestMapping(value = "/product/add", method = RequestMethod.POST)
    boolean add(@RequestBody Product product);

    @RequestMapping(value = "/product/get/{id}", method = RequestMethod.GET)
    Product get(@PathVariable("id") Long id);

    @RequestMapping(value = "/product/list", method = RequestMethod.GET)
    List<Product> list();
}

2、控制器调用feign

ProductController_Feign

import com.mengxuegu.springcloud.entities.Product;
import com.mengxuegu.springcloud.service.ProductClientService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;

@RestController
public class ProductController_Feign {
    @Autowired
    private ProductClientService productClientService;

    @RequestMapping(value = "/consumer/product/add")
    public boolean add(Product product) {
        return productClientService.add(product);
    }

    @RequestMapping(value = "/consumer/product/get/{id}")
    public Product get(@PathVariable("id") Long id) {
        return productClientService.get(id);
    }

    @RequestMapping(value = "/consumer/product/list")
    public List<Product> list() {
        return productClientService.list();
    }
}

3、启动类添加注解@EnableFeignClients

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.openfeign.EnableFeignClients;


//会扫描指定包下面使用@FeignClient标识的接口
@EnableFeignClients(basePackages = "com.mengxuegu.springcloud.service")
@SpringBootApplication
@EnableEurekaClient //标识 是一个Eureka客户端
public class ProductConsumer_80_Feign {

    public static void main(String[] args) {
        SpringApplication.run(ProductConsumer_80_Feign.class, args);
    }

}

4、pom.xml

<dependencies>
    <dependency>
        <groupId>com.mengxuegu.springcloud</groupId>
        <artifactId>microservice-cloud-02-api</artifactId>
        <version>${project.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <!-- Ribbon 相关依赖,eureka会自动引入Ribbon -->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    </dependency>

    <!--feign 依赖-->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-openfeign</artifactId>
    </dependency>
</dependencies>

5、验证截图