Fixed checkstyle.

spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-nacos-discovery/src/main/java/com/alibaba/cloud/nacos/NacosDiscoveryProperties.java

@@ -19,11 +19,11 @@ package com.alibaba.cloud.nacos;
 import java.net.Inet4Address;
 import java.net.InetAddress;
 import java.net.NetworkInterface;
-import java.util.HashMap;
-import java.util.Properties;
-import java.util.Objects;
 import java.util.Enumeration;
+import java.util.HashMap;
 import java.util.Map;
+import java.util.Objects;
+import java.util.Properties;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -46,7 +46,16 @@ import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.core.env.ConfigurableEnvironment;
 import org.springframework.core.env.Environment;
 
-import static com.alibaba.nacos.api.PropertyKeyConst.*;
+import static com.alibaba.nacos.api.PropertyKeyConst.ACCESS_KEY;
+import static com.alibaba.nacos.api.PropertyKeyConst.CLUSTER_NAME;
+import static com.alibaba.nacos.api.PropertyKeyConst.ENDPOINT;
+import static com.alibaba.nacos.api.PropertyKeyConst.ENDPOINT_PORT;
+import static com.alibaba.nacos.api.PropertyKeyConst.NAMESPACE;
+import static com.alibaba.nacos.api.PropertyKeyConst.NAMING_LOAD_CACHE_AT_START;
+import static com.alibaba.nacos.api.PropertyKeyConst.PASSWORD;
+import static com.alibaba.nacos.api.PropertyKeyConst.SECRET_KEY;
+import static com.alibaba.nacos.api.PropertyKeyConst.SERVER_ADDR;
+import static com.alibaba.nacos.api.PropertyKeyConst.USERNAME;
 
 /**
  * @author dungu.zpf

spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-nacos-discovery/src/main/java/com/alibaba/cloud/nacos/discovery/ServiceCache.java

@@ -1,3 +1,19 @@
+/*
+ * Copyright 2013-2022 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package com.alibaba.cloud.nacos.discovery;
 
 import java.util.Collections;
@@ -16,7 +32,10 @@ import org.springframework.cloud.client.ServiceInstance;
  * @author freeman
  * @since 2022.0
  */
-public class ServiceCache {
+public final class ServiceCache {
+
+	private ServiceCache() {
+	}
 
 	private static List<String> services = Collections.emptyList();
 

spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-nacos-discovery/src/main/java/com/alibaba/cloud/nacos/discovery/reactive/NacosReactiveDiscoveryClient.java

@@ -24,11 +24,11 @@ import com.alibaba.nacos.api.exception.NacosException;
 import org.reactivestreams.Publisher;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.springframework.beans.factory.annotation.Value;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.core.scheduler.Schedulers;
 
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.cloud.client.ServiceInstance;
 import org.springframework.cloud.client.discovery.ReactiveDiscoveryClient;