SpringCloud -根据服务名获取服务运行实例并进行负载均衡

Nacos注册中心

每个服务启动之后都要向注册中心发送服务注册请求,注册中心可以和各个注册客户端自定义协议实现服务注册和发现。

  • pom.xml
xml 复制代码
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
  • 启动服务


获取服务实例测试
java 复制代码
@EnableDiscoveryClient
@SpringBootApplication
public class Main83
{
    public static void main(String[] args)
    {
        ConfigurableApplicationContext applicationContext = SpringApplication.run(Main83.class, args);

        DiscoveryClient discoveryClient = applicationContext.getBean(DiscoveryClient.class);
        List<ServiceInstance> instances = discoveryClient.getInstances("nacos-payment-provider");
        for (ServiceInstance instance : instances) {
            System.out.println("instance.getHost() = " + instance.getHost());
            System.out.println("instance.getPort() = " + instance.getPort());
        }

        NacosDiscoveryClient nacosDiscoveryClient = applicationContext.getBean(NacosDiscoveryClient.class);
        List<ServiceInstance> serviceInstances = nacosDiscoveryClient.getInstances("nacos-payment-provider");
        for (ServiceInstance instance : serviceInstances) {
            System.out.println("Nacos instance.getHost() = " + instance.getHost());
            System.out.println("instance.getPort() = " + instance.getPort());
        }

        LoadBalancerClient balancerClient = applicationContext.getBean(LoadBalancerClient.class);
        System.out.println("balancerClient.choose(\"nacos-payment-provider\").getPort() = " + balancerClient.choose("nacos-payment-provider").getPort());
        System.out.println("balancerClient.choose(\"nacos-payment-provider\").getPort() = " + balancerClient.choose("nacos-payment-provider").getPort());
        System.out.println("balancerClient.choose(\"nacos-payment-provider\").getPort() = " + balancerClient.choose("nacos-payment-provider").getPort());
        System.out.println("balancerClient.choose(\"nacos-payment-provider\").getPort() = " + balancerClient.choose("nacos-payment-provider").getPort());
        System.out.println("balancerClient.choose(\"nacos-payment-provider\").getPort() = " + balancerClient.choose("nacos-payment-provider").getPort());
        System.out.println("balancerClient.choose(\"nacos-payment-provider\").getPort() = " + balancerClient.choose("nacos-payment-provider").getPort());

    }


}

在引入注册中心相关的依赖后,注册中心的相关API会实现SpringCloud规范,自动给容器中存入DiscoveryClient对象,引入了Nacos,就是NacosDiscoveryClient。通过DiscoveryClient接口提供的能力可以从注册中心实时拉取服务列表。

  • 负载均衡实现
    微服务在自动进行服务发现后,进行的是客户端负载均衡,也就是客户端自己维护了一套负载均衡算法,每次请求选择某一台服务器进行请求。

pom.xml

xml 复制代码
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-loadbalancer</artifactId>
        </dependency>
java 复制代码
LoadBalancerClient balancerClient = applicationContext.getBean(LoadBalancerClient.class);
        System.out.println("balancerClient.choose(\"nacos-payment-provider\").getPort() = " + balancerClient.choose("nacos-payment-provider").getPort());
        System.out.println("balancerClient.choose(\"nacos-payment-provider\").getPort() = " + balancerClient.choose("nacos-payment-provider").getPort());
        System.out.println("balancerClient.choose(\"nacos-payment-provider\").getPort() = " + balancerClient.choose("nacos-payment-provider").getPort());
        System.out.println("balancerClient.choose(\"nacos-payment-provider\").getPort() = " + balancerClient.choose("nacos-payment-provider").getPort());
        System.out.println("balancerClient.choose(\"nacos-payment-provider\").getPort() = " + balancerClient.choose("nacos-payment-provider").getPort());
        System.out.println("balancerClient.choose(\"nacos-payment-provider\").getPort() = " + balancerClient.choose("nacos-payment-provider").getPort());

LoadBalancerClient类会自动使用容器中的DiscoveryClient进行服务的负载均衡。

相关推荐
kangkang-1 小时前
PC端基于SpringBoot架构控制无人机(三):系统架构设计
java·架构·无人机
界面开发小八哥3 小时前
「Java EE开发指南」如何用MyEclipse创建一个WEB项目?(三)
java·ide·java-ee·myeclipse
idolyXyz3 小时前
[java: Cleaner]-一文述之
java
一碗谦谦粉4 小时前
Maven 依赖调解的两大原则
java·maven
netyeaxi4 小时前
Java:使用spring-boot + mybatis如何打印SQL日志?
java·spring·mybatis
收破烂的小熊猫~4 小时前
《Java修仙传:从凡胎到码帝》第四章:设计模式破万法
java·开发语言·设计模式
猴哥源码4 小时前
基于Java+SpringBoot的动物领养平台
java·spring boot
老任与码4 小时前
Spring AI Alibaba(1)——基本使用
java·人工智能·后端·springaialibaba
小兵张健4 小时前
武汉拿下 23k offer 经历
java·面试·ai编程
FreeBuf_5 小时前
Apache组件遭大规模攻击:Tomcat与Camel高危RCE漏洞引发数千次利用尝试
java·tomcat·apache