content: 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<String, StreamInfo>();
  
      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;
      }
  
  }