fix(nacos): fix issue #859

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

@@ -17,52 +17,25 @@
 package com.alibaba.cloud.nacos;
 
 import com.alibaba.nacos.api.config.ConfigService;
-import org.springframework.beans.BeansException;
-import org.springframework.context.ApplicationContext;
-import org.springframework.context.ApplicationContextAware;
+import org.springframework.beans.factory.annotation.Autowired;
+
+import java.util.Objects;
 
 /**
  * @author <a href="mailto:liaochunyhm@live.com">liaochuntao</a>
  */
-public class NacosConfigManager implements ApplicationContextAware {
+public class NacosConfigManager {
+
+	@Autowired
+	private NacosConfigProperties properties;
+
+	private static ConfigService service = null;
 
 	public ConfigService getConfigService() {
-		return ServiceHolder.getInstance().getService();
-	}
-
-	@Override
-	public void setApplicationContext(ApplicationContext applicationContext)
-			throws BeansException {
-		NacosConfigProperties properties = applicationContext
-				.getBean(NacosConfigProperties.class);
-		ServiceHolder holder = ServiceHolder.getInstance();
-		if (!holder.alreadyInit) {
-			ServiceHolder.getInstance().setService(properties.configServiceInstance());
-		}
-	}
-
-	static class ServiceHolder {
-		private ConfigService service = null;
-
-		private boolean alreadyInit = false;
-
-		private static final ServiceHolder holder = new ServiceHolder();
-
-		ServiceHolder() {
-		}
-
-		static ServiceHolder getInstance() {
-			return holder;
-		}
-
-		void setService(ConfigService service) {
-			alreadyInit = true;
-			this.service = service;
-		}
-
-		ConfigService getService() {
-			return service;
+		if (Objects.isNull(service)) {
+			service = properties.configServiceInstance();
 		}
+		return service;
 	}
 
 }