content: /*
   * Copyright 1999-2023 Alibaba Group Holding Ltd.
   *
   * 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
   *
   *      http://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.nacos.example;
  
  import com.alibaba.nacos.api.config.ConfigFactory;
  import com.alibaba.nacos.api.config.ConfigService;
  import com.alibaba.nacos.api.config.listener.AbstractFuzzyWatchEventWatcher;
  import com.alibaba.nacos.api.config.listener.FuzzyWatchEventWatcher;
  import com.alibaba.nacos.api.config.listener.ConfigFuzzyWatchChangeEvent;
  import com.alibaba.nacos.api.exception.NacosException;
  
  import java.util.Properties;
  
  /**
   * Nacos config fuzzy listen example.
   * <p>
   * Add the JVM parameter to run the NamingExample:
   * {@code -DserverAddr=${nacos.server.ip}:${nacos.server.port} -Dnamespace=${namespaceId}}
   * </p>
   * <p>
   * This example demonstrates how to use fuzzy listening for Nacos configuration.
   * </p>
   * <p>
   * Fuzzy listening allows you to monitor configuration changes that match a specified pattern.
   * </p>
   * <p>
   * In this example, we publish several configurations with names starting with "test", and then add a fuzzy listener to
   * listen for changes to configurations with names starting with "test".
   * </p>
   * <p>
   * After publishing the configurations, the example waits for a brief period, then cancels the fuzzy listening.
   * </p>
   *
   * @author stone-98
   * @date 2024/3/14
   */
  public class ConfigFuzzyWatchExample {
      
      public static void main(String[] args) throws NacosException, InterruptedException {
          // Set up properties for Nacos Config Service
          Properties properties = new Properties();
          properties.setProperty("serverAddr", System.getProperty("serverAddr", "localhost"));
          properties.setProperty("namespace", System.getProperty("namespace", "public"));
          
          // Create a Config Service instance
          ConfigService configService = ConfigFactory.createConfigService(properties);
          
          int publicConfigNum = 10;
          // Publish some configurations for testing
          for (int i = 0; i < publicConfigNum; i++) {
              boolean isPublishOk = configService.publishConfig("test" + i, "DEFAULT_GROUP", "content");
              System.out.println("[publish result] " + isPublishOk);
          }
          
          // Define a fuzzy listener to handle configuration changes
          FuzzyWatchEventWatcher listener = new AbstractFuzzyWatchEventWatcher() {
              @Override
              public void onEvent(ConfigFuzzyWatchChangeEvent event) {
                  System.out.println("[fuzzy listen config change]" + event.toString());
              }
          };
          
          // Add the fuzzy listener to monitor configurations starting with "test"
          configService.fuzzyWatch("test*", "DEFAULT_GROUP", listener);
          System.out.println("[Fuzzy listening started.]");
          
          // Publish more configurations to trigger the listener
          Thread.sleep(1000);
          boolean isPublishOkOne = configService.publishConfig("test-one", "DEFAULT_GROUP", "content");
          System.out.println("[publish result] " + isPublishOkOne);
          
          boolean isPublishOkTwo = configService.publishConfig("nacos-test-two", "DEFAULT_GROUP", "content");
          System.out.println("[publish result] " + isPublishOkTwo);
          
          boolean isPublishOkThree = configService.publishConfig("test", "DEFAULT_GROUP", "content");
          System.out.println("[publish result] " + isPublishOkThree);
          
          // Wait briefly before canceling the fuzzy listening
          Thread.sleep(1000);
          System.out.println("Cancel fuzzy listen...");
          
          // Sleep to keep the program running for observation
          Thread.sleep(3000);
      }
  }
  