文件目录结构

文件目录结构很重要，特别注意的是rule文件要放在主启动类上一级位置，才能够扫描。

写pom

<dependencies> <!--springboot 2.2.2--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <!--Spring cloud Hoxton.SR1--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-actuator</artifactId> </dependency> <!--Spring cloud alibaba 2.1.0.RELEASE--> <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> <!--Eureka-Client--> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId> </dependency>

因为eureka的依赖已经整合了ribbon的依赖，所以不用额外引入新的东西。

改yml

server: port: 80spring: application: name: cloud-book-consumereureka: client: register-with-eureka: false fetch-registry: true service-url: defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka

主启动

@SpringBootApplication@EnableEurekaClient@RibbonClient(name = "CLOUD-BOOK-SERVICE", configuration = LoadBalanceRule.class) //更换轮询算法public class RestTemplateMain80 { public static void main(String[] args) { SpringApplication.run(RestTemplateMain80.class,args); }}

业务逻辑

rules层

在图示文件目录下新建LoadBalanceRule.class，用于更换负载均衡算法。

@Configurationpublic class LoadBalanceRule { @Bean public IRule iRule() { // 定义为随机 return new RandomRule(); }}

config层

开启restTemplate负载均衡
在config文件夹下创建LoadBalanceConfig.class

@Configurationpublic class LoadBalanceConfig { @Bean @LoadBalanced //开启负载均衡 public RestTemplate getReatTemplate(){ return new RestTemplate(); }}

controller层

新建BookController.class
写业务代码

@RestController@Slf4jpublic class BookController { @Resource private RestTemplate restTemplate; public static final String PAYMENT_URL = "http://CLOUD-BOOK-SERVICE"; @GetMapping(value = "restTemplate/book/getAllBooks")//只要json数据时 public CommonResult getAllBooks(){ return restTemplate.getForObject(PAYMENT_URL+"/book/getAllBooks",CommonResult.class); } @GetMapping("restTemplate/book/getAllBooks2") //需要知道更多数据时，使用getForEntity方法 public CommonResult getAllBooks2(){ ResponseEntity<CommonResult> resultResponseEntit = restTemplate.getForEntity(PAYMENT_URL+"/book/getAllBooks",CommonResult.class); if (resultResponseEntit.getStatusCode().is2xxSuccessful()){ log.info(resultResponseEntit.getStatusCode()+"\t"+resultResponseEntit.getHeaders()); return resultResponseEntit.getBody(); }else { return new CommonResult<>(444,"操作失败"); } } @GetMapping(value = "restTemplate/book/index") public String index() { return restTemplate.getForObject(PAYMENT_URL+"/book/index",String.class); }}

使用restTemplate+Ribboin实现服务调用和负载均衡完成。

手写Ribbon负载均衡算法 lb层

1.新建LoadBalancer接口，添加代码

public interface LoadBalancer { ServiceInstance instances(List<ServiceInstance> serviceInstances);}

2.新建实现类MyLB

@Componentpublic class MyLB implements LoadBalancer { private AtomicInteger atomicInteger = new AtomicInteger(0); //求第几次访问 自旋锁思想 public final int getAndIncrement(){ int current; int next; do { current = this.atomicInteger.get(); next = current >=2147483647 ? 0 : current+1; }while(!this.atomicInteger.compareAndSet(current,next)); System.out.println("***第几次访问next->"+next); return next; } //负载均衡算法,实现roundRobin算法 @Override public ServiceInstance instances(List<ServiceInstance> serviceInstances) { int index = getAndIncrement() % serviceInstances.size(); return serviceInstances.get(index); }}

修改BookController

@RestController@Slf4jpublic class BookController { @Resource private RestTemplate restTemplate; @Resource private LoadBalancer loadBalancer; @Resource private DiscoveryClient discoveryClient; public static final String PAYMENT_URL = "http://CLOUD-BOOK-SERVICE"; @GetMapping(value = "restTemplate/book/getAllBooks")//只要json数据时 public CommonResult getAllBooks(){ List<ServiceInstance> instances = discoveryClient.getInstances("CLOUD-BOOK-SERVICE"); if (instances == null || instances.size() <= 0){ return null; } ServiceInstance serviceInstance = loadBalancer.instances(instances); URI uri = serviceInstance.getUri(); return restTemplate.getForObject(uri+"/book/getAllBooks",CommonResult.class); } @GetMapping(value = "restTemplate/book/index") public String index() { List<ServiceInstance> instances = discoveryClient.getInstances("CLOUD-BOOK-SERVICE"); if (instances == null || instances.size() <= 0){ return null; } ServiceInstance serviceInstance = loadBalancer.instances(instances); URI uri = serviceInstance.getUri(); return restTemplate.getForObject(uri+"/book/index",String.class); }}

修改文件注解

• 删去主启动类的更换负载均衡算法注解

@RibbonClient(name = “CLOUD-BOOK-SERVICE”, configuration = LoadBalanceRule.class)

• 删去LoadBalanceConfig中开启负载均衡算法注解

@LoadBalanced

手写Ribbon算法并使用完成

以上就是Ribbon和RestTemplate实现服务调用与负载均衡的详细内容，更多关于Ribbon和RestTemplate服务与负载的资料请关注其它相关文章！