Android Open Source - spades Hash Map Fetch Strategy

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License

The source code is released under:

Apache License

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Java Source Code

/**
 * Copyright (C) 2013 Pau Picas Sans <pau.picas@gmail.com>
 *//from   w w  w. j av a2 s  .c  o m
 * 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 cat.picas.spades.fetch;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import android.database.Cursor;
import cat.picas.spades.CursorInfo;
import cat.picas.spades.Dao.EntityConsumer;
import cat.picas.spades.Entity;
import cat.picas.spades.EntityMapper;
import cat.picas.spades.Table;

public class HashMapFetchStrategy<T extends Entity> implements FetchStrategy<T> {
  private Table mTable;
  private EntityMapper<T> mMapper;

  public HashMapFetchStrategy(Table table, EntityMapper<T> mapper) {
    mTable = table;
    mMapper = mapper;
  }

  @Override
  public List<T> fetchAll(Cursor cursor, CursorInfo cursorInfo, EntityConsumer<T> consumer) {
    if (!cursorInfo.hasTable(mTable)) {
      Collections.emptyList();
    }

    Map<Long, T> map = new HashMap<Long, T>();

    int oldPosition = cursor.getPosition();
    int idColIndex = cursorInfo.getColumnIndex(mTable.getColumnId());

    cursor.moveToPosition(-1);
    while (cursor.moveToNext()) {
      T entity = map.get(cursor.getLong(idColIndex));
      if (entity == null) {
        entity = mMapper.createFromCursor(cursor, cursorInfo);
        if (entity != null) {
          map.put(entity.getEntityId(), entity);
        }
      }
      if (consumer != null && entity != null) {
        consumer.accept(cursor, cursorInfo, entity);
      }
    }

    cursor.moveToPosition(oldPosition);

    return new ArrayList<T>(map.values());
  }
}

Java Source Code List