| /** |
| * 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.storm.hbase.topology; |
| |
| |
| import backtype.storm.topology.OutputFieldsDeclarer; |
| import backtype.storm.tuple.Fields; |
| import backtype.storm.tuple.ITuple; |
| import backtype.storm.tuple.Values; |
| import org.apache.hadoop.hbase.Cell; |
| import org.apache.hadoop.hbase.CellUtil; |
| import org.apache.hadoop.hbase.client.Result; |
| import org.apache.hadoop.hbase.util.Bytes; |
| import org.apache.storm.hbase.bolt.mapper.HBaseValueMapper; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * Takes a Hbase result and returns a value list that has a value instance for each column and corresponding value. |
| * So if the result from Hbase was |
| * <pre> |
| * WORD, COUNT |
| * apple, 10 |
| * bannana, 20 |
| * </pre> |
| * |
| * this will return |
| * <pre> |
| * [WORD, apple] |
| * [COUNT, 10] |
| * [WORD, banana] |
| * [COUNT, 20] |
| * </pre> |
| * |
| */ |
| public class WordCountValueMapper implements HBaseValueMapper { |
| |
| @Override |
| public List<Values> toValues(ITuple tuple, Result result) throws Exception { |
| List<Values> values = new ArrayList<Values>(); |
| Cell[] cells = result.rawCells(); |
| for(Cell cell : cells) { |
| Values value = new Values (Bytes.toString(CellUtil.cloneQualifier(cell)), Bytes.toLong(CellUtil.cloneValue(cell))); |
| values.add(value); |
| } |
| return values; |
| } |
| |
| @Override |
| public void declareOutputFields(OutputFieldsDeclarer declarer) { |
| declarer.declare(new Fields("columnName","columnValue")); |
| } |
| |
| } |