微服務(wù)進(jìn)行遠(yuǎn)程調(diào)用其他服務(wù)方式

更新時(shí)間：2026年01月23日 09:13:05 作者：裊沫

文章主要介紹了如何將本地服務(wù)注冊到Nacos地址上,并詳細(xì)描述了服務(wù)調(diào)用和負(fù)載均衡的實(shí)現(xiàn)方法,包括使用`@EnableDiscoveryClient`注解開啟服務(wù)調(diào)用、編寫調(diào)用接口、創(chuàng)建RestTemplate配置類以及使用負(fù)載均衡依賴進(jìn)行服務(wù)調(diào)用

1、服務(wù)調(diào)用

現(xiàn)在我們需要使用service-order服務(wù)調(diào)用sercice-business服務(wù)

使用@EnableDiscoveryClient注解，開啟服務(wù)調(diào)用

引入依賴

        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

需要被調(diào)用的服務(wù)啟動類：

@EnableDiscoveryClient //開啟服務(wù)調(diào)用
@SpringBootApplication
public class BusinessMainApplication{
    public static void main(String[] args) {
        SpringApplication.run(BusinessMainApplication.class,args);
    }
}

編寫需要進(jìn)行調(diào)用的接口：

    @GetMapping("/business/{id}")
    public Business getById(@PathVariable("id") String id){
        return  businessService.getBusiness(id);
    }

創(chuàng)建RestTemplate配置類，防止new 多個(gè)對象

@Configuration
public class OrderConfig {

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

在服務(wù)層進(jìn)行調(diào)用另外一個(gè)服務(wù)

@Slf4j
@Service
public class OrderServiceImpl implements OrderService {

    @Autowired
    private DiscoveryClient discoveryClient;

    @Autowired
    private RestTemplate restTemplate;


    @Override
    public Order getById(Long id) {
        Order order = new Order();
        order.setTotalAmount(new BigDecimal("1000"));
        order.setNickName("尚硅谷");
        order.setId(id);
        order.setProductList(Lists.newArrayList());
        return order;
    }

    @Override
    public Order createOrder(Long userId, Long productId) {
        //進(jìn)行遠(yuǎn)程調(diào)用獲取商品數(shù)據(jù)
        Business businessById = getBusinessById(productId.toString());

        Order order = new Order();
        order.setId(1L);
        order.setAddress("將軍大道108號");
        order.setTotalAmount(BigDecimal.valueOf(businessById.getPrice() * businessById.getCount()));
        order.setNickName("尚硅谷");
        order.setUserId(userId);
        order.setProductList(Arrays.asList(businessById));
        return order;
    }

    /**
     * 手動選擇需要的實(shí)例進(jìn)行調(diào)用
     * @param businessId
     * @return
     */
    public Business getBusinessById(String businessId){
        List<ServiceInstance> instances = discoveryClient.getInstances("service-business");

        //獲取服務(wù)的第幾個(gè)實(shí)例對象
        ServiceInstance instance = instances.get(0);
        //端口的URL
        String url = "http://" + instance.getHost() + ":"  + instance.getPort() + "/business/" + businessId;

        log.info("遠(yuǎn)程調(diào)用的URL:" + url);

        //進(jìn)行遠(yuǎn)程調(diào)用
        Business forObject = restTemplate.getForObject(url, Business.class);
        log.info("返回的數(shù)據(jù):" + forObject.toString());
        return forObject;
    }

}

2、負(fù)載均衡

如果被調(diào)用的服務(wù)有多個(gè)實(shí)例，現(xiàn)在我們?yōu)榱藴p輕某個(gè)服務(wù)的壓力，對服務(wù)進(jìn)行輪詢調(diào)用：

現(xiàn)在我們需要在調(diào)用方，使用loadBanlancer依賴

依賴引入：

  <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-loadbalancer</artifactId>
        </dependency>

依賴導(dǎo)入：

@Slf4j
@Service
public class OrderServiceImpl implements OrderService {

    @Autowired
    private DiscoveryClient discoveryClient;

    @Autowired
    private RestTemplate restTemplate;

    @Autowired
    private LoadBalancerClient loadBalancerClient;

    @Override
    public Order getById(Long id) {
        Order order = new Order();
        order.setTotalAmount(new BigDecimal("1000"));
        order.setNickName("尚硅谷");
        order.setId(id);
        order.setProductList(Lists.newArrayList());
        return order;
    }

    @Override
    public Order createOrder(Long userId, Long productId) {
        //進(jìn)行遠(yuǎn)程調(diào)用獲取商品數(shù)據(jù)
//        Business businessById = getBusinessById(productId.toString());
//        Business businessById = getBusinessByIdWithLoadBalancer(productId.toString());
        Business businessById = getBusinessByIdWithAnnotation(productId.toString());

        Order order = new Order();
        order.setId(1L);
        order.setAddress("將軍大道108號");
        order.setTotalAmount(BigDecimal.valueOf(businessById.getPrice() * businessById.getCount()));
        order.setNickName("尚硅谷");
        order.setUserId(userId);
        order.setProductList(Arrays.asList(businessById));
        return order;
    }

    /**
     * 手動選擇需要的實(shí)例進(jìn)行調(diào)用
     * @param businessId
     * @return
     */
    public Business getBusinessById(String businessId){
        List<ServiceInstance> instances = discoveryClient.getInstances("service-business");

        //獲取服務(wù)的第幾個(gè)實(shí)例對象
        ServiceInstance instance = instances.get(0);
        //端口的URL
        String url = "http://" + instance.getHost() + ":"  + instance.getPort() + "/business/" + businessId;

        log.info("遠(yuǎn)程調(diào)用的URL:" + url);

        //進(jìn)行遠(yuǎn)程調(diào)用
        Business forObject = restTemplate.getForObject(url, Business.class);
        log.info("返回的數(shù)據(jù):" + forObject.toString());
        return forObject;
    }


    /**
     * 使用LoadBalancer進(jìn)行負(fù)載均衡
     * @param businessId
     * @return
     */
    public Business getBusinessByIdWithLoadBalancer(String businessId){

        ServiceInstance choose = loadBalancerClient.choose("service-business");
        //端口的URL
        String url = "http://" + choose.getHost() + ":"  + choose.getPort() + "/business/" + businessId;

        log.info("IP:" + choose.getHost() + ":" + choose.getPort());
        log.info("遠(yuǎn)程調(diào)用的URL:" + url);

        //進(jìn)行遠(yuǎn)程調(diào)用
        Business forObject = restTemplate.getForObject(url, Business.class);
        log.info("返回的數(shù)據(jù):" + forObject.toString());
        return forObject;
    }


    /**
     * 使用注解@LoadBalancer進(jìn)行負(fù)載均衡
     * 需要在restTemplate上添加注解LoadBalancer
     * @param businessId
     * @return
     */
    public Business getBusinessByIdWithAnnotation(String businessId){

        String url = "http://service-business/business/" + businessId;


        //進(jìn)行遠(yuǎn)程調(diào)用
        Business forObject = restTemplate.getForObject(url, Business.class);
        log.info("返回的數(shù)據(jù):" + forObject.toString());
        return forObject;
    }


}

其中，第三種，使用注解的方式進(jìn)行負(fù)載均衡，需要將注解添加在restTemplate配置類上

@Configuration
public class OrderConfig {

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