RowMapperResultsExtractor.java

/*
 * Copyright 2011-2013 the original author or authors.
 * 
 * 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 org.springframework.data.hadoop.hbase;

import java.util.ArrayList;
import java.util.List;

import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.springframework.util.Assert;

/**
 * Adapter encapsulating the RowMapper callback. 
 * 
 * @author Costin Leau
 */
class RowMapperResultsExtractor<T> implements ResultsExtractor<List<T>> {

	private final RowMapper<T> rowMapper;

	/**
	 * Create a new RowMapperResultSetExtractor.
	 * @param rowMapper the RowMapper which creates an object for each row
	 */
	public RowMapperResultsExtractor(RowMapper<T> rowMapper) {
		Assert.notNull(rowMapper, "RowMapper is required");
		this.rowMapper = rowMapper;
	}

	public List<T> extractData(ResultScanner results) throws Exception {
		List<T> rs = new ArrayList<T>();
		int rowNum = 0;
		for (Result result : results) {
			rs.add(this.rowMapper.mapRow(result, rowNum++));
		}
		return rs;
	}
}