content: package org.apache.lucene.document;
  
  /**
   * 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.
   */
  
  import java.util.Arrays;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  /**
   * A {@link FieldSelector} based on a Map of field names to {@link FieldSelectorResult}s
   *
   */
  public class MapFieldSelector implements FieldSelector {
      
      Map<String,FieldSelectorResult> fieldSelections;
      
      /** Create a a MapFieldSelector
       * @param fieldSelections maps from field names (String) to {@link FieldSelectorResult}s
       */
      public MapFieldSelector(Map<String,FieldSelectorResult> fieldSelections) {
          this.fieldSelections = fieldSelections;
      }
      
      /** Create a a MapFieldSelector
       * @param fields fields to LOAD.  List of Strings.  All other fields are NO_LOAD.
       */
      public MapFieldSelector(List<String> fields) {
          fieldSelections = new HashMap<String,FieldSelectorResult>(fields.size()*5/3);
          for (final String field : fields)
              fieldSelections.put(field, FieldSelectorResult.LOAD);
      }
      
      /** Create a a MapFieldSelector
       * @param fields fields to LOAD.  All other fields are NO_LOAD.
       */
      public MapFieldSelector(String... fields) {
        this(Arrays.asList(fields));
      }
  
  
      
      /** Load field according to its associated value in fieldSelections
       * @param field a field name
       * @return the fieldSelections value that field maps to or NO_LOAD if none.
       */
      public FieldSelectorResult accept(String field) {
          FieldSelectorResult selection = fieldSelections.get(field);
          return selection!=null ? selection : FieldSelectorResult.NO_LOAD;
      }
      
  }
  