Merge branch '3.0.x'

spring-cloud-kubernetes-discovery/src/main/java/org/springframework/cloud/kubernetes/discovery/KubernetesDiscoveryClient.java

@@ -17,13 +17,11 @@
 package org.springframework.cloud.kubernetes.discovery;
 
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.List;
 import java.util.stream.Collectors;
 
 import org.springframework.cloud.client.ServiceInstance;
 import org.springframework.cloud.client.discovery.DiscoveryClient;
-import org.springframework.util.CollectionUtils;
 import org.springframework.util.StringUtils;
 import org.springframework.web.client.RestTemplate;
 
@@ -51,35 +49,33 @@ public class KubernetesDiscoveryClient implements DiscoveryClient {
 
 	@Override
 	public List<ServiceInstance> getInstances(String serviceId) {
-		List<ServiceInstance> response = Collections.emptyList();
 		KubernetesServiceInstance[] responseBody = rest.getForEntity(
 				properties.getDiscoveryServerUrl() + "/apps/" + serviceId, KubernetesServiceInstance[].class).getBody();
 		if (responseBody != null && responseBody.length > 0) {
-			response = Arrays.stream(responseBody).filter(this::matchNamespaces).collect(Collectors.toList());
+			return Arrays.stream(responseBody).filter(this::matchNamespaces).collect(Collectors.toList());
 		}
-		return response;
+		return List.of();
 	}
 
 	@Override
 	public List<String> getServices() {
-		List<String> response = Collections.emptyList();
 		Service[] services = rest.getForEntity(properties.getDiscoveryServerUrl() + "/apps", Service[].class).getBody();
 		if (services != null && services.length > 0) {
-			response = Arrays.stream(services).filter(this::matchNamespaces).map(Service::getName)
+			return Arrays.stream(services).filter(this::matchNamespaces).map(Service::getName)
 					.collect(Collectors.toList());
 		}
-		return response;
+		return List.of();
 	}
 
 	private boolean matchNamespaces(KubernetesServiceInstance kubernetesServiceInstance) {
-		if (CollectionUtils.isEmpty(properties.getNamespaces())) {
+		if (properties.getNamespaces().isEmpty()) {
 			return true;
 		}
 		return properties.getNamespaces().contains(kubernetesServiceInstance.getNamespace());
 	}
 
 	private boolean matchNamespaces(Service service) {
-		if (CollectionUtils.isEmpty(service.getServiceInstances())) {
+		if (service.getServiceInstances().isEmpty()) {
 			return true;
 		}
 		return service.getServiceInstances().stream().anyMatch(this::matchNamespaces);

spring-cloud-kubernetes-discovery/src/main/java/org/springframework/cloud/kubernetes/discovery/KubernetesDiscoveryClientProperties.java

@@ -16,7 +16,6 @@
 
 package org.springframework.cloud.kubernetes.discovery;
 
-import java.util.ArrayList;
 import java.util.List;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
@@ -35,7 +34,7 @@ public class KubernetesDiscoveryClientProperties {
 	 * If set then only the services and endpoints matching these namespaces will be
 	 * fetched from the Kubernetes API server.
 	 */
-	private List<String> namespaces = new ArrayList<>();
+	private List<String> namespaces = List.of();
 
 	public String getDiscoveryServerUrl() {
 		return discoveryServerUrl;

spring-cloud-kubernetes-discovery/src/main/java/org/springframework/cloud/kubernetes/discovery/Service.java

@@ -25,7 +25,7 @@ public class Service {
 
 	private String name;
 
-	private List<KubernetesServiceInstance> serviceInstances;
+	private List<KubernetesServiceInstance> serviceInstances = List.of();
 
 	public Service() {
 	}