公司一直使用的都是dubbo,很少使用springcloud,自学下

安装nacos

nacos即是配置中心也是注册中心，安装参考nacas大致如下

1. 修改conf/application.properties文件，nacos支持mysql数据源配置（目前只支持mysql），添加mysql数据源的url、用户名和密码。不知道怎么安装mysql参考安装mysql
2. sh startup.sh -m standalone 启动

1.构建provider

整体是比较简单的，大家照着下面的配置直接贴代码就行。注意x替换为自己的ip或者包名

pom.xml

  <properties>
        <java.version>1.8</java.version>
        <jackson.version>2.12.4</jackson.version>
        <project.version>1.0.0</project.version>
        <maven-compiler-plugin.version>3.8.1</maven-compiler-plugin.version>
        <maven-source.version>3.2.1</maven-source.version>
        <lombok.version>1.18.12</lombok.version>
        <spring.boot.version>2.3.2.RELEASE</spring.boot.version>
        <spring.cloud.version>Hoxton.SR9</spring.cloud.version>
        <spring.cloud.alibaba.version>2.2.6.RELEASE</spring.cloud.alibaba.version>
    </properties>

 <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>${spring.boot.version}</version>
        <relativePath/>
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

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

    <dependencies>
        <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>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
    </dependencies>
  <!-- 一般只要在项目的root下的pom.xml中加上上面那些配置 而只需要保留下面的-->
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

启动类

@SpringBootApplication
/**这个注解非常重要**/
@EnableDiscoveryClient
public class ProviderApplication {

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

    @RestController
    public class EchoController {
        @GetMapping(value = "/echo/{string}")
        public String echo(@PathVariable String string) {
            return "Hello Nacos Discovery " + string;
        }
    }
}

application.properties

server.port=8082
spring.application.name=demo-provider
server.servlet.context-path:/provider
spring.cloud.nacos.discovery.server-addr=你的nacosIp地址:8848
management.endpoints.web.exposure.include=*

2.构建consumer的配置

启动类配置

@SpringBootApplication
@MapperScan("com.xxx.demo.dao.mapper")
@ComponentScan(basePackages = {"com.xxx.demo"})
@RestController
@Slf4j
@EnableDiscoveryClient
@EnableFeignClients(basePackages = {"com.xxx.demo.service.feign"})
public class DemoApplication {

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

上图中@EnableDiscoveryClient @EnableFeignClients 这两个注解注意

申明feign的调用

注意这边的要跟provider写的一摸一样，当人也可以把provider的抽象出来提取为api接口，在消费者这边继承。

@FeignClient(name = "demo-provider", path = "/provider")
public interface ProviderClient {

    @GetMapping("/echo/{string}")
    String hello(@PathVariable String string);
}

pom的配置

与consumer一样

服务端controller

能够调用成功

public class FeignController {
    @Resource
    private ProviderClient providerClient;

    /**
     *  openfeign示例
     * @param string 请求入参
     * @return 返回参数
     */
    @RequestMapping(value = "/consumer/{string}",method = RequestMethod.GET)
    public String consume(@PathVariable String string){
        return providerClient.hello(string);
    }

}

消费者application.properties

# 新增如下配置 替换为自己的nacos地址
spring.cloud.nacos.discovery.server-addr=x.x.x.x:8848
management.endpoints.web.exposure.include=*

3.整个项目结构

image.png

4.参考

1.springcloud-alibaba
2.Spring Boot 整合 OpenFeign + Nacos 的坑