SpringCloud openfeign相互调用实现方法介绍

2022-11-30 10:15 开发作者：文明冲浪

一、准备工作

1、安装nacos，地址：Releases · alibaba/nacos · github

2、springboot与springcloud之间的版本对应关系

我使用的版本：

springboot：2.4.2

springcloud：2020.0.1

springcloud alibaba：2021.1

二、新建一个springcloud项目

1、首先打开idea，新建一个maven项目，并将src文件夹删除

SpringCloud openfeign相互调用实现方法介绍

2、在pom.XML中添加依赖

<?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.example</groupId>
    <artifactId>my-demo</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSwww.devze.comHOT</version>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <properties>
        <Java.version>1.8</java.version>
        <!--spring cloud 版本-->
        <spring-cloud.version>2020.0.1</spring-cloud.version>
        <spring-cloud-alibaba.version>2021.1</spring-cloud-alibaba.version>
    </properties>
    <dependencies>
        <dependency>
            <gropythonupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        开发者_JS开发    <version>8.0.29</version>
        </dependency>
        <!--引入配置中心阿里巴巴-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
        </dependency>
        <!--引入注册中心阿里巴巴-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spri编程ng-cloud-alibaba-dependencies</a编程客栈rtifactId>
                <version>${spring-cloud-alibaba.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>myBATis-plus-boot-starter</artifactId>
                <version>3.4.2</version>
            </dependency>
        </dependencies>
    </dependencyManagement>
</project>

3、在根目录下分别新建maven子项目provider和consumer

SpringCloud openfeign相互调用实现方法介绍

4、修改provider和consumer的pom.xml文件

（1）给consumer添加依赖，openfeign和loadbalancer。注意，服务消费者一定要引入loadbalancer依赖，否则会报错。

<!--OpenFeign为HTTP形式的Rest API提供了非常简洁高效的RPC调用方式-->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
<!--loadbalancer是Spring Cloud官方自己提供的客户端负载均衡器,抽象和实现，用来替代Ribbon-->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-loadbalancer</artifactId>
</dependency>

（2）provider暂时不用添加依赖

5、为provider和consumer添加配置文件application.yml

# provider
server:
port: 8001
spring:
application:
name: provider
cloud:
nacos:
discovery:
server-addr: 127.0.0.1:8848 # nacos服务的端口号为8848
# consumer
server:
port: 8002
spring:
application:
name: consumer
cloud:
nacos:
discovery:
server-addr: 127.0.0.1:8848

6、给provider和consumer添加启动类

（1）ProviderApplication.java

@SpringBootApplication
@EnableDiscoveryClient
public class ProviderApplication {
    public static void main(String[] args) {
        SpringApplication.run(ProviderApplication.class, args);
    }
}

（2）ConsumerApplication.java

@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
public class ConsumerApplication {
    public static void main(String[] args) {
        SpringApplication.run(ConsumerApplication.class, args);
    }
}

consumer是消费者，需要调用provider服务，故需要加上@EnableFeignClients注解

5、编写provider生产者的服务，一个简单功能，返回“hello world”

@RestController
@RequestMapping("/provider")
public class ProviderController {
    @GetMapping("/test")
    public String test() {
        return "hello world";
    }
}

6、在consumer中新建client接口，用于调用provider中的方法

@FeignClient("provider")  // 括号中为目标服务名
public interface ProviderClient {
    @GetMapping("provider/test")  // 目标方法的url
    String hello();
}

7、在consumer的controller中调用client接口

@RestController
@RequestMapping("/consumer")
public class ConsumerController {
    @Autowired
    ProviderClient providerClient;
    @GetMapping("/feignTest")
    public String test() {
        return providerClient.hello();
    }
}

8、启动项目

（1）启动nacos，将nacos下载安装好android以后，进入nacos中的bin文件夹。Windows系统用.cmd文件，linux和MACOS系统用.sh文件

SpringCloud openfeign相互调用实现方法介绍