content: /**
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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 backtype.storm.topology;
  
  import backtype.storm.generated.StreamInfo;
  import backtype.storm.tuple.Fields;
  import backtype.storm.utils.Utils;
  import java.util.HashMap;
  import java.util.Map;
  
  public class OutputFieldsGetter implements OutputFieldsDeclarer {
      private Map<String, StreamInfo> _fields = new HashMap<>();
  
      public void declare(Fields fields) {
          declare(false, fields);
      }
  
      public void declare(boolean direct, Fields fields) {
          declareStream(Utils.DEFAULT_STREAM_ID, direct, fields);
      }
  
      public void declareStream(String streamId, Fields fields) {
          declareStream(streamId, false, fields);
      }
  
      public void declareStream(String streamId, boolean direct, Fields fields) {
          if (_fields.containsKey(streamId)) {
              throw new IllegalArgumentException("Fields for " + streamId + " already set");
          }
          _fields.put(streamId, new StreamInfo(fields.toList(), direct));
      }
  
      public Map<String, StreamInfo> getFieldsDeclaration() {
          return _fields;
      }
  
  }