SpringCloud Ribbon負載均衡程式碼例項
阿新 • • 發佈:2020-03-13
1.新增依賴
<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.新增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埠,也有可能是8772埠 //引數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.新增Ribbon呼叫公共類
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; @Component public class RibbonUtils { @Autowired private RestTemplate restTemplate; private static RestTemplate template; //@PostConstruct修飾的方法會在伺服器載入Servlet的時候執行,並且只會被伺服器呼叫一次 @PostConstruct public void init() { template = restTemplate; } /** * * @param uri 介面地址 * @param responseType 返回型別 * * */ public static <T> T get(String uri,Class<T> responseType) { return template.getForObject(uri,responseType); } /** * * @param uri 介面地址 * @param responseType 返回型別 * @param request 傳遞引數 * * */ public static <T> T get(String uri,Class<T> responseType,Map<String,?> request) { return template.getForObject(uri,responseType,request); } /** * * @param uri 介面地址 * @param responseType 返回型別 * @param request 傳遞引數 * @param headerMap 報頭資訊 * * */ public static <T> T get(String uri,?> request,String> headerMap) { //新增報頭 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的型別定為String,這裡使用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,request); return result.getBody(); } /** * * @param uri 介面地址 * @param responseType 返回型別 * @param body 傳遞實體 * @param headers 報頭資訊 * * */ public static <T> T post(String uri,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上測試兩個介面即可
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