feature:add PolarisRateLimiterLimitedFallback spi.

spring-cloud-tencent-polaris-loadbalancer/src/main/java/com/tencent/cloud/polaris/loadbalancer/LoadBalancerUtils.java

@@ -18,10 +18,9 @@
 
 package com.tencent.cloud.polaris.loadbalancer;
 
+import java.time.Duration;
 import java.util.Collections;
 import java.util.List;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.stream.Collectors;
 
@@ -32,8 +31,6 @@ import com.tencent.polaris.api.pojo.DefaultServiceInstances;
 import com.tencent.polaris.api.pojo.Instance;
 import com.tencent.polaris.api.pojo.ServiceInstances;
 import com.tencent.polaris.api.pojo.ServiceKey;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import reactor.core.publisher.Flux;
 
 import org.springframework.cloud.client.ServiceInstance;
@@ -45,8 +42,6 @@ import org.springframework.util.CollectionUtils;
  * @author lepdou 2022-05-17
  */
 public final class LoadBalancerUtils {
-	private static final Logger LOGGER = LoggerFactory.getLogger(LoadBalancerUtils.class);
-
 	private static final int WAIT_TIME = 3;
 
 	private LoadBalancerUtils() {
@@ -59,25 +54,11 @@ public final class LoadBalancerUtils {
 	 * @return ServiceInstances
 	 */
 	public static ServiceInstances transferServersToServiceInstances(Flux<List<ServiceInstance>> servers) {
-		CountDownLatch latch = new CountDownLatch(1);
-
-		AtomicReference<List<Instance>> instancesRef = new AtomicReference<>();
-		servers.subscribe(serviceInstances -> {
-			instancesRef.set(serviceInstances
-					.stream()
-					.map(LoadBalancerUtils::transferServerToServiceInstance)
-					.collect(Collectors.toList()));
-
-			latch.countDown();
-		});
-
-		try {
-			latch.await(WAIT_TIME, TimeUnit.SECONDS);
-		}
-		catch (InterruptedException e) {
-			LOGGER.error("Wait get instance result error. ", e);
-		}
-
+		AtomicReference<List<Instance>> instancesRef = servers.map(serviceInstances -> serviceInstances
+						.stream()
+						.map(LoadBalancerUtils::transferServerToServiceInstance)
+						.collect(Collectors.toList())).collect(AtomicReference<List<Instance>>::new, AtomicReference::set)
+				.block(Duration.ofSeconds(WAIT_TIME));
 		String serviceName = "";
 		if (!CollectionUtils.isEmpty(instancesRef.get())) {
 			serviceName = instancesRef.get().get(0).getService();
@@ -95,7 +76,7 @@ public final class LoadBalancerUtils {
 	 * @param serviceInstance serviceInstance
 	 * @return defaultInstance
 	 */
-	public static DefaultInstance transferServerToServiceInstance(ServiceInstance serviceInstance) {
+	public static Instance transferServerToServiceInstance(ServiceInstance serviceInstance) {
 		DefaultInstance instance = new DefaultInstance();
 		instance.setNamespace(MetadataContext.LOCAL_NAMESPACE);
 		instance.setService(serviceInstance.getServiceId());