文件目錄結構

文件目錄結構很重要，特別注意的是rule文件要放在主啟動類上一級位置，才能夠掃描。

寫pom

1. <dependencies>
2. <!--springboot 2.2.2-->
3. <dependency>
4. <groupId>org.springframework.boot</groupId>
5. <artifactId>spring-boot-starter-web</artifactId>
6. </dependency>
7. <!--Spring cloud Hoxton.SR1-->
8. <dependency>
9. <groupId>org.springframework.boot</groupId>
10. <artifactId>spring-boot-starter-actuator</artifactId>
11. </dependency>
12. <!--Spring cloud alibaba 2.1.0.RELEASE-->
13. <dependency>
14. <groupId>org.projectlombok</groupId>
15. <artifactId>lombok</artifactId>
16. <optional>true</optional>
17. </dependency>
18. <dependency>
19. <groupId>org.springframework.boot</groupId>
20. <artifactId>spring-boot-starter-test</artifactId>
21. <scope>test</scope>
22. </dependency>
23. <!--Eureka-Client-->
24. <dependency>
25. <groupId>org.springframework.cloud</groupId>
26. <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
27. </dependency>

因為eureka的依賴已經整合了ribbon的依賴，所以不用額外引入新的東西。

改yml

1. server:
2. port: 80
3. spring:
4. application:
5. name: cloud-book-consumer
6. eureka:
7. client:
8. register-with-eureka: false
9. fetch-registry: true
10. service-url:
11. defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka

主啟動

1. @SpringBootApplication
2. @EnableEurekaClient
3. @RibbonClient(name = "CLOUD-BOOK-SERVICE", configuration = LoadBalanceRule.class) //更換輪詢算法
4. public class RestTemplateMain80 {
5. public static void main(String[] args) {
6. SpringApplication.run(RestTemplateMain80.class,args);
7. }
8. }

業務邏輯

rules層

在圖示文件目錄下新建LoadBalanceRule.class，用于更換負載均衡算法。

1. @Configuration
2. public class LoadBalanceRule {
3. @Bean
4. public IRule iRule() {
5. // 定義為隨機
6. return new RandomRule();
7. }
8. }

config層

開啟restTemplate負載均衡
在config文件夾下創建LoadBalanceConfig.class

1. @Configuration
2. public class LoadBalanceConfig {
3. @Bean
4. @LoadBalanced //開啟負載均衡
5. public RestTemplate getReatTemplate(){
6. return new RestTemplate();
7. }
8. }

controller層

新建BookController.class
寫業務代碼

1. @RestController
2. @Slf4j
3. public class BookController {
4. @Resource
5. private RestTemplate restTemplate;
6.  
7. public static final String PAYMENT_URL = "http://CLOUD-BOOK-SERVICE";
8.  
9. @GetMapping(value = "restTemplate/book/getAllBooks")//只要json數據時
10. public CommonResult getAllBooks(){
11. return restTemplate.getForObject(PAYMENT_URL+"/book/getAllBooks",CommonResult.class);
12. }
13.  
14. @GetMapping("restTemplate/book/getAllBooks2") //需要知道更多數據時，使用getForEntity方法
15. public CommonResult getAllBooks2(){
16. ResponseEntity<CommonResult> resultResponseEntit = restTemplate.getForEntity(PAYMENT_URL+"/book/getAllBooks",CommonResult.class);
17. if (resultResponseEntit.getStatusCode().is2xxSuccessful()){
18. log.info(resultResponseEntit.getStatusCode()+"\t"+resultResponseEntit.getHeaders());
19. return resultResponseEntit.getBody();
20. }else {
21. return new CommonResult<>(444,"操作失敗");
22. }
23. }
24. @GetMapping(value = "restTemplate/book/index")
25. public String index() {
26. return restTemplate.getForObject(PAYMENT_URL+"/book/index",String.class);
27. }
28. }

使用restTemplate+Ribboin實現服務調用和負載均衡完成。

手寫Ribbon負載均衡算法 lb層

1.新建LoadBalancer接口，添加代碼

1. public interface LoadBalancer {
2. ServiceInstance instances(List<ServiceInstance> serviceInstances);
3. }

2.新建實現類MyLB

1. @Component
2. public class MyLB implements LoadBalancer {
3.  
4. private AtomicInteger atomicInteger = new AtomicInteger(0);
5. //求第幾次訪問 自旋鎖思想
6. public final int getAndIncrement(){
7. int current;
8. int next;
9. do {
10. current = this.atomicInteger.get();
11. next = current >=2147483647 ? 0 : current+1;
12. }while(!this.atomicInteger.compareAndSet(current,next));
13. System.out.println("***第幾次訪問next->"+next);
14. return next;
15. }
16.  
17. //負載均衡算法,實現roundRobin算法
18. @Override
19. public ServiceInstance instances(List<ServiceInstance> serviceInstances) {
20.  
21. int index = getAndIncrement() % serviceInstances.size();
22.  
23. return serviceInstances.get(index);
24. }
25. }

修改BookController

1. @RestController
2. @Slf4j
3. public class BookController {
4. @Resource
5. private RestTemplate restTemplate;
6.  
7. @Resource
8. private LoadBalancer loadBalancer;
9.  
10. @Resource
11. private DiscoveryClient discoveryClient;
12.  
13. public static final String PAYMENT_URL = "http://CLOUD-BOOK-SERVICE";
14.  
15. @GetMapping(value = "restTemplate/book/getAllBooks")//只要json數據時
16. public CommonResult getAllBooks(){
17. List<ServiceInstance> instances = discoveryClient.getInstances("CLOUD-BOOK-SERVICE");
18. if (instances == null || instances.size() <= 0){
19. return null;
20. }
21. ServiceInstance serviceInstance = loadBalancer.instances(instances);
22. URI uri = serviceInstance.getUri();
23. return restTemplate.getForObject(uri+"/book/getAllBooks",CommonResult.class);
24. }
25.  
26. @GetMapping(value = "restTemplate/book/index")
27. public String index() {
28. List<ServiceInstance> instances = discoveryClient.getInstances("CLOUD-BOOK-SERVICE");
29. if (instances == null || instances.size() <= 0){
30. return null;
31. }
32. ServiceInstance serviceInstance = loadBalancer.instances(instances);
33. URI uri = serviceInstance.getUri();
34. return restTemplate.getForObject(uri+"/book/index",String.class);
35. }
36. }

修改文件注解

• 刪去主啟動類的更換負載均衡算法注解

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

• 刪去LoadBalanceConfig中開啟負載均衡算法注解

@LoadBalanced

手寫Ribbon算法并使用完成

以上就是Ribbon和RestTemplate實現服務調用與負載均衡的詳細內容，更多關于Ribbon和RestTemplate服務與負載的資料請關注服務器之家其它相關文章！

原文鏈接：https://blog.csdn.net/super1223/article/details/115384982