content: /*
   * Copyright 2010-2025 Hyland Software, Inc. and its affiliates.
   *
   * 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 org.activiti.engine.impl.persistence;
  
  import com.fasterxml.uuid.EthernetAddress;
  import com.fasterxml.uuid.Generators;
  import com.fasterxml.uuid.impl.TimeBasedGenerator;
  import org.activiti.engine.impl.cfg.IdGenerator;
  
  /**
   * {@link IdGenerator} implementation based on the current time and the ethernet address of the machine it is running on.
   *
  
   */
  public class StrongUuidGenerator implements IdGenerator {
  
      // different ProcessEngines on the same classloader share one generator.
      protected static TimeBasedGenerator timeBasedGenerator;
  
      public StrongUuidGenerator() {
          ensureGeneratorInitialized();
      }
  
      protected void ensureGeneratorInitialized() {
          if (timeBasedGenerator == null) {
              synchronized (StrongUuidGenerator.class) {
                  if (timeBasedGenerator == null) {
                      timeBasedGenerator = Generators.timeBasedGenerator(EthernetAddress.fromInterface());
                  }
              }
          }
      }
  
      public String getNextId() {
          return timeBasedGenerator.generate().toString();
      }
  }
  