Spring Boot 单体应用升级 Spring Cloud 微服务最佳实践

<properties>
    <spring-cloud-alibaba.version>2022.0.0.0</spring-cloud-alibaba.version>
    <spring-cloud.version>2022.0.0</spring-cloud.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>
    <!-- Nacos 服务发现 -->
    <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
    </dependency>
    <!-- 服务发现：OpenFeign服务调用 -->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-openfeign</artifactId>
    </dependency>
  <!-- 负载均衡器 -->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-loadbalancer</artifactId>
    </dependency>
</dependencies>

spring:
  application:
    #项目名称必填，在注册中心唯一
    #最好和之前域名规范、kubernetes service名等保持一致（会作为调用）
    name: service-provider
  cloud:
    nacos:
      discovery: #启用 spring cloud nacos discovery
        server-addr: 127.0.0.1:8848

#项目名称必填，在注册中心唯一；最好和之前域名规范保持一致，第四步会讲到原因
spring.application.name=service-provider
#启用 spring cloud nacos discovery
spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848

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

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

@RestController
 public class TestController {

    @Autowired
    private RestTemplate restTemplate;

    @GetMapping(value = "/echo-rest/{str}")
    public String rest(@PathVariable String str) {
        return restTemplate.getForObject("http://service-provider/echo/" + str, String.class);
    }
}

//@FeignClient(name = "service-provider", url="http://service.example.com/")
@FeignClient(name = "service-provider")
public interface EchoService {
    @GetMapping(value = "/echo/{str}")
    String echo(@PathVariable("str") String str);
}

@RestController
 public class TestController {

    @Autowired
    private EchoService echoService;

    @GetMapping(value = "/echo-feign/{str}")
    public String feign(@PathVariable String str) {
        return echoService.echo(str);
    }
}