refactor: modify the initialization of ApplicationContextAwareUtils.

Signed-off-by: Haotian Zhang <928016560@qq.com>

CHANGELOG.md

@@ -4,4 +4,4 @@
 - [feat: Add config address to report client url conversion.](https://github.com/Tencent/spring-cloud-tencent/pull/1795)
 - [feat: Update config server IP to 127.0.0.1 and adjust tests.](https://github.com/Tencent/spring-cloud-tencent/pull/1796)
 - [feat: Support Polaris config env value and add related tests](https://github.com/Tencent/spring-cloud-tencent/pull/1797)
-- [refactor: modify the initialization of ApplicationContextAwareUtils.](https://github.com/Tencent/spring-cloud-tencent/pull/1778)
+- [refactor: modify the initialization of ApplicationContextAwareUtils.](https://github.com/Tencent/spring-cloud-tencent/pull/1798)

spring-cloud-tencent-examples/quickstart-example/quickstart-callee-service-b/src/main/java/com/tencent/cloud/quickstart/callee/service/CalleeServiceChangeCallback.java

@@ -0,0 +1,60 @@
+/*
+ * Tencent is pleased to support the open source community by making spring-cloud-tencent available.
+ *
+ * Copyright (C) 2021 Tencent. All rights reserved.
+ *
+ * Licensed under the BSD 3-Clause License (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://opensource.org/licenses/BSD-3-Clause
+ *
+ * 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.tencent.cloud.quickstart.callee.service;
+
+import java.util.List;
+
+import com.tencent.cloud.polaris.discovery.refresh.ServiceInstanceChangeCallback;
+import com.tencent.cloud.polaris.discovery.refresh.ServiceInstanceChangeListener;
+import com.tencent.polaris.api.pojo.Instance;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.springframework.stereotype.Component;
+
+/**
+ * Call back for QuickstartCalleeService.
+ *
+ * @author Haotian Zhang
+ */
+@Component
+@ServiceInstanceChangeListener(serviceName = "QuickstartCalleeService")
+public class CalleeServiceChangeCallback implements ServiceInstanceChangeCallback {
+
+	private static final Logger LOG = LoggerFactory.getLogger(CalleeServiceChangeCallback.class);
+
+	@Override
+	public void callback(List<Instance> currentServiceInstances, List<Instance> addServiceInstances, List<Instance> deleteServiceInstances) {
+		String current = generateNodeList(currentServiceInstances);
+		String add = generateNodeList(addServiceInstances);
+		String delete = generateNodeList(deleteServiceInstances);
+		LOG.info("current: {}, add: {}, delete: {}", current, add, delete);
+	}
+
+	private String generateNodeList(List<Instance> deleteServiceInstances) {
+		StringBuilder nodeListStr = new StringBuilder("[");
+		for (Instance instance : deleteServiceInstances) {
+			if (nodeListStr.length() > 1) {
+				nodeListStr.append(", ");
+			}
+			nodeListStr.append(instance.getHost()).append(":").append(instance.getPort());
+		}
+		nodeListStr.append("]");
+		return nodeListStr.toString();
+	}
+}