Merge pull request #843 from yidadi/master

Optimizing and reusing code

spring-cloud-alibaba-nacos-config/src/main/java/com/alibaba/cloud/nacos/NacosPropertySourceRepository.java

@@ -16,11 +16,11 @@
 
 package com.alibaba.cloud.nacos;
 
-import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.ConcurrentHashMap;
 
 import com.alibaba.cloud.nacos.client.NacosPropertySource;
+import com.google.common.collect.Lists;
 
 /**
  * @author xiaojing
@@ -34,9 +34,7 @@ public class NacosPropertySourceRepository {
 	 * @return all nacos properties from application context
 	 */
 	public static List<NacosPropertySource> getAll() {
-		List<NacosPropertySource> result = new ArrayList<>();
-		result.addAll(NACOS_PROPERTY_SOURCE_REPOSITORY.values());
-		return result;
+		return Lists.newArrayList(NACOS_PROPERTY_SOURCE_REPOSITORY.values());
 	}
 
 	public static void collectNacosPropertySources(

spring-cloud-alibaba-nacos-config/src/main/java/com/alibaba/cloud/nacos/client/NacosPropertySourceBuilder.java

@@ -83,7 +83,10 @@ public class NacosPropertySourceBuilder {
 		String data = null;
 		try {
 			data = configService.getConfig(dataId, group, timeout);
-			if (!StringUtils.isEmpty(data)) {
+			if (StringUtils.isEmpty(data)) {
+				return EMPTY_PROPERTIES;
+			}
+
 			log.info(String.format("Loading nacos data, dataId: '%s', group: '%s'",
 					dataId, group));
 
@@ -99,8 +102,6 @@ public class NacosPropertySourceBuilder {
 				yamlFactory.setResources(new ByteArrayResource(data.getBytes()));
 				return yamlFactory.getObject();
 			}
-
-			}
 		}
 		catch (NacosException e) {
 			log.error("get data from Nacos error,dataId:{}, ", dataId, e);

spring-cloud-alibaba-nacos-discovery/src/main/java/com/alibaba/cloud/nacos/ribbon/NacosServerList.java

@@ -22,6 +22,7 @@ import java.util.List;
 import com.alibaba.cloud.nacos.NacosDiscoveryProperties;
 import com.alibaba.nacos.api.naming.pojo.Instance;
 
+import com.alibaba.nacos.client.naming.utils.CollectionUtils;
 import com.netflix.client.config.IClientConfig;
 import com.netflix.loadbalancer.AbstractServerList;
 
@@ -64,7 +65,7 @@ public class NacosServerList extends AbstractServerList<NacosServer> {
 
 	private List<NacosServer> instancesToServerList(List<Instance> instances) {
 		List<NacosServer> result = new ArrayList<>();
-		if (null == instances) {
+		if (CollectionUtils.isEmpty(instances)) {
 			return result;
 		}
 		for (Instance instance : instances) {