《SpringCloud专题13》-OpenFeign服务接口调用

1.概述

1.1.OpenFeign是什么

官网:​​https://cloud.spring.io/spring-cloud-static/Hoxton.SR1/reference/htmlsingle/#spring-cloud-openfeign​​​

Feign是一个声明式的Web服务客户端,让编写Web服务客户端变得非常容易,只需 创建一个接口并在接口上添加注解即可

1.2.能干嘛

1.3.Feign和OpenFeign两者区别

2.OpenFeign使用步骤

接口+注解

微服务调用接口+@FeignClient

2.1.新建cloud-consumer-feign-order80

2.2.新建cloud-consumer-feign-order80

<?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>springcloud2020</artifactId>
        <groupId>com.itxiongmao.springcloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloud-comsumer-feign-order80</artifactId>

    <dependencies>
        
        <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>

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

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

        <dependency>
            <groupId>com.itxiongmao.springcloud</groupId>
            <artifactId>cloud-api-commons</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>compile</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>

    </dependencies>


</project>      

2.3.YML

server:
  port: 80

spring:
  application:
    name: cloud-comsumer-feign-order80

eureka:
  client:
    service-url:
      # 集群版
      defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka      

2.4.主启动

package com.itxiongmao;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration;
import org.springframework.cloud.openfeign.EnableFeignClients;

@SpringBootApplication
@EnableFeignClients //开启FeignClient
public class OrderFeignMain80 {

    public static void main(String[] args) {
        SpringApplication.run(OrderFeignMain80.class,args);
    }
}      

2.5.业务类

业务逻辑接口+@FeignClient配置调用provider服务

新建PaymentFeignService接口并新增注解@FeignClient

```java`

package com.itxiongmao.service;

import com.itxiongmao.springcloud.entities.CommonResult;
import com.itxiongmao.springcloud.entities.Payment;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;

@Component
@FeignClient(value = "CLOUD-PAYMENT-SERVICE")
public interface PaymentFeignService {

    /**
     * 通过主键查询单条数据
     *
     * @param id 主键
     * @return 单条数据
     */
    @GetMapping("payment/get/{id}")
    CommonResult<Payment> selectOne(@PathVariable("id") Long id);

    @GetMapping("payment/feign/timeout")
    String getFeignTimeOut();
}      

2.6.控制层Controller

package com.itxiongmao.controller;

import com.itxiongmao.service.PaymentFeignService;
import com.itxiongmao.springcloud.entities.CommonResult;
import com.itxiongmao.springcloud.entities.Payment;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

@RestController
@RequestMapping("order")
public class OrderFeignController {

    @Resource
    private PaymentFeignService paymentFeignService;

    @GetMapping("selectOne/{id}")
    public CommonResult<Payment> selectOne(@PathVariable("id") Long id){
        return paymentFeignService.selectOne(id);
    }

    @GetMapping("/feign/timeout")
    public String getFeignTimeOut() {
        return paymentFeignService.getFeignTimeOut();
    }
}      

2.6.测试

先启动2个eureka集群7001/7002
再启动2个微服务8001/8002
启动OpenFeign
http://localhost/order/selectOne/123      

2.7.小总结