SpringCloud Ribbon负载均衡代码实例

1.添加依赖

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-netflix-eureka-client</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-netflix-ribbon</artifactId></dependency><!-- lombok --><dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional></dependency>

2.修改启动类

import org.mybatis.spring.annotation.MapperScan;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.cloud.client.loadbalancer.LoadBalanced;import org.springframework.context.annotation.Bean;import org.springframework.web.client.RestTemplate;@SpringBootApplication@MapperScan('cn.ytheng.order_service')public class OrderServiceApplication { /** * @Loadbalanced负载均衡策略 */ @Bean @LoadBalanced public RestTemplate restTemplate() { return new RestTemplate(); } public static void main(String[] args) { SpringApplication.run(OrderServiceApplication.class, args); }}

3.添加Controller

import cn.theng.order_service.utils.RibbonUtils;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.cloud.client.ServiceInstance;import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;import org.springframework.util.LinkedMultiValueMap;import org.springframework.web.bind.annotation.PostMapping;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestParam;import org.springframework.web.bind.annotation.RestController;import org.springframework.web.client.RestTemplate;import java.util.HashMap;import java.util.Map;@RestController@RequestMapping('/api/v1/order')public class ProductOrderController { @RequestMapping('/test') public Object test(@RequestParam('product_id') int productId) { //方法一// ServiceInstance instance = loadBalancerClient.choose('product-service');// String url = String.format('http://%s:%s/api/v1/product/find?id=' + productId, instance.getHost(), instance.getPort());// RestTemplate template = new RestTemplate();// Map<String, Object> map2 = template.getForObject(url, Map.class); //负载均衡 //商品列表启用两个节点时 //由客户端来自动选择节点，可能是8771端口，也有可能是8772端口 //参数id名称需要保持一致 //方法二(推荐) String uri = 'http://product-service/api/v1/product/find?id={id}'; Map<String, Object> request = new HashMap<>(); request.put('id', productId); Map<String, Object> map3 = RibbonUtils.get(uri, Map.class, request); return 'success'; } @PostMapping('/test2') public Object test2(@RequestParam('product_id') int productId) { Product product = new Product(); product.setId(productId); String uri = 'http://product-service/api/v1/product/find2'; LinkedMultiValueMap<String, String> headers = new LinkedMultiValueMap<>(); headers.add('token', 'theng'); Object result = RibbonUtils.post(uri, Object.class, product, headers); return 'success'; }}

4.添加Ribbon调用公共类

import org.springframework.beans.factory.annotation.Autowired;import org.springframework.http.*;import org.springframework.stereotype.Component;import org.springframework.util.LinkedMultiValueMap;import org.springframework.web.client.RestTemplate;import javax.annotation.PostConstruct;import java.util.Arrays;import java.util.Collections;import java.util.Map;@Componentpublic class RibbonUtils { @Autowired private RestTemplate restTemplate; private static RestTemplate template; //@PostConstruct修饰的方法会在服务器加载Servlet的时候运行，并且只会被服务器调用一次 @PostConstruct public void init() { template = restTemplate; } /** * * @param uri 接口地址 * @param responseType 返回类型 * * */ public static <T> T get(String uri, Class<T> responseType) { return template.getForObject(uri, responseType); } /** * * @param uri 接口地址 * @param responseType 返回类型 * @param request 传递参数 * * */ public static <T> T get(String uri, Class<T> responseType, Map<String, ?> request) { return template.getForObject(uri, responseType, request); } /** * * @param uri 接口地址 * @param responseType 返回类型 * @param request 传递参数 * @param headerMap 报头信息 * * */ public static <T> T get(String uri, Class<T> responseType, Map<String, ?> request, Map<String, String> headerMap) { //添加报头 HttpHeaders headers = new HttpHeaders(); headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON)); for(Map.Entry<String, String> entry : headerMap.entrySet()){ String mapKey = entry.getKey(); String mapValue = entry.getValue(); headers.add(mapKey, mapValue); } //body的类型定为String,这里使用get没有用到body,post会使用到 HttpEntity<String> entity = new HttpEntity<String>(null, headers); ResponseEntity<T> result = template.exchange(uri, HttpMethod.GET, entity, responseType, request); return result.getBody(); } /** * * @param uri 接口地址 * @param responseType 返回类型 * @param body 传递实体 * @param headers 报头信息 * * */ public static <T> T post(String uri, Class<T> responseType, Object body, LinkedMultiValueMap<String, String> headers) { if (!headers.containsKey('Content-Type')) { headers.put('Content-Type', Collections.singletonList('application/json;charset=UTF-8')); } HttpEntity request = new HttpEntity(body, headers); Object obj = template.postForObject(uri, request, responseType); return (T) obj; }}

5.在PostMan上测试两个接口即可

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持好吧啦网。