core/src/main/java/org/apache/calcite/avatica/util/MapIteratorCursor.java

/*
 * 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 org.apache.calcite.avatica.util;

import java.util.Iterator;
import java.util.List;
import java.util.Map;

/**
 * Implementation of {@link Cursor} on top of an
 * {@link java.util.Iterator} that
 * returns a {@link Map} for each row.
 *
 * <p>The Map contains (field, value) pairs.
 */
public class MapIteratorCursor extends IteratorCursor<Map<String, Object>> {
  private final List<String> fieldNames;

  /**
   * Creates a MapIteratorCursor.
   *
   * @param iterator Iterator
   * @param fieldNames Field names to project
   */
  public MapIteratorCursor(Iterator<Map<String, Object>> iterator,
      List<String> fieldNames) {
    super(iterator);
    assert fieldNames != null;
    this.fieldNames = fieldNames;
  }

  protected Getter createGetter(int ordinal) {
    return new MapGetter<String>(fieldNames.get(ordinal));
  }
}

// End MapIteratorCursor.java