Merge pull request #1094 from yuhuangbin/issue#980

Add default values for some configuration items

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

@@ -81,7 +81,7 @@ public class NacosConfigProperties {
 					.resolvePlaceholders("${spring.cloud.nacos.config.server-addr:}");
 			if (StringUtils.isEmpty(serverAddr)) {
 				serverAddr = environment
-						.resolvePlaceholders("${spring.cloud.nacos.server-addr:}");
+						.resolvePlaceholders("${spring.cloud.nacos.server-addr:localhost:8848}");
 			}
 			this.setServerAddr(serverAddr);
 		}

spring-cloud-alibaba-nacos-config/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -3,6 +3,7 @@
     {
       "name": "spring.cloud.nacos.server-addr",
       "type": "java.lang.String",
+      "defaultValue": "localhost:8848",
       "description": "nacos server address."
     },
     {

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

@@ -431,7 +431,7 @@ public class NacosDiscoveryProperties {
 					.resolvePlaceholders("${spring.cloud.nacos.discovery.server-addr:}");
 			if (StringUtils.isEmpty(serverAddr)) {
 				serverAddr = env
-						.resolvePlaceholders("${spring.cloud.nacos.server-addr:}");
+						.resolvePlaceholders("${spring.cloud.nacos.server-addr:localhost:8848}");
 			}
 			this.setServerAddr(serverAddr);
 		}

spring-cloud-alibaba-nacos-discovery/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -2,6 +2,7 @@
     {
       "name": "spring.cloud.nacos.server-addr",
       "type": "java.lang.String",
+      "defaultValue": "localhost:8848",
       "description": "nacos server address."
     },
     {

spring-cloud-alibaba-sentinel-datasource/src/main/java/com/alibaba/cloud/sentinel/datasource/config/NacosDataSourceProperties.java

@@ -54,11 +54,7 @@ public class NacosDataSourceProperties extends AbstractDataSourceProperties {
 	public void preCheck(String dataSourceName) {
 		if (StringUtils.isEmpty(serverAddr)) {
 			serverAddr = this.getEnv().getProperty(
-					"spring.cloud.sentinel.datasource.nacos.server-addr", "");
-			if (StringUtils.isEmpty(serverAddr)) {
-				throw new IllegalArgumentException(
-						"NacosDataSource server-addr is empty");
-			}
+					"spring.cloud.sentinel.datasource.nacos.server-addr", "localhost:8848");
 		}
 	}