SpringCloud Ribbon負載均衡代碼實例
1.添加依賴
<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.修改啟動類
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負載均衡策略 */ @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); //負載均衡 //商品列表啟用兩個節點時 //由客戶端來自動選擇節點,可能是8771端口,也有可能是8772端口 //參數id名稱需要保持一致 //方法二(推薦) 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調用公共類
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修飾的方法會在服務器加載Servlet的時候運行,并且只會被服務器調用一次 @PostConstruct public void init() { template = restTemplate; } /** * * @param uri 接口地址 * @param responseType 返回類型 * * */ public static <T> T get(String uri, Class<T> responseType) { return template.getForObject(uri, responseType); } /** * * @param uri 接口地址 * @param responseType 返回類型 * @param request 傳遞參數 * * */ 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 返回類型 * @param request 傳遞參數 * @param headerMap 報頭信息 * * */ public static <T> T get(String uri, Class<T> responseType, Map<String, ?> request, Map<String, String> headerMap) { //添加報頭 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的類型定為String,這里使用get沒有用到body,post會使用到 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 返回類型 * @param body 傳遞實體 * @param headers 報頭信息 * * */ 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上測試兩個接口即可
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支持好吧啦網。
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