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.spring.integration;
  
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Set;
  import java.util.concurrent.ConcurrentSkipListSet;
  import org.springframework.integration.mapping.HeaderMapper;
  import org.springframework.messaging.MessageHeaders;
  
  /**
  
   */
  public class ProcessVariableHeaderMapper implements HeaderMapper<Map<String, Object>> {
  
      private final Set<String> keysToPreserve = new ConcurrentSkipListSet<String>();
  
      public ProcessVariableHeaderMapper(Set<String> sync) {
          this.keysToPreserve.addAll(sync);
      }
  
      @Override
      public void fromHeaders(MessageHeaders headers, Map<String, Object> target) {
          // inbound SI msg. take the headers and convert it to
          sync(this.keysToPreserve, headers, target);
      }
  
      @Override
      public Map<String, Object> toHeaders(Map<String, Object> source) {
          Map<String, Object> matches = sync(this.keysToPreserve, source, new HashMap<String, Object>());
          return matches;
      }
  
      private static Map<String, Object> sync(Set<String> keys, Map<String, Object> in, Map<String, Object> out) {
          for (String k : keys) if (in.containsKey(k)) out.put(k, in.get(k));
          return out;
      }
  }
  