| /* |
| * 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.hadoop.chukwa.extraction.demux.processor.reducer; |
| |
| |
| import java.util.HashMap; |
| |
| import org.apache.log4j.Logger; |
| |
| public class ReduceProcessorFactory { |
| static Logger log = Logger.getLogger(ReduceProcessorFactory.class); |
| |
| // TODO |
| // add new mapper package at the end. |
| // We should have a more generic way to do this. |
| // Ex: read from config |
| // list of alias |
| // and |
| // alias -> processor class |
| |
| // ******** WARNING ******** |
| // If the ReduceProcessor is not there use Identity instead |
| |
| private static HashMap<String, ReduceProcessor> processors = new HashMap<String, ReduceProcessor>(); // registry |
| |
| private ReduceProcessorFactory() { |
| } |
| |
| /** |
| * Register a specific parser for a {@link ReduceProcessor} implementation. |
| * @param reduceType is data type assigned by mapper |
| * @param processor is parser class for reducer |
| */ |
| public static synchronized void register(String reduceType, |
| ReduceProcessor processor) { |
| log.info("register " + processor.getClass().getName() |
| + " for this recordType :" + reduceType); |
| if (processors.containsKey(reduceType)) { |
| throw new DuplicateReduceProcessorException( |
| "Duplicate processor for recordType:" + reduceType); |
| } |
| ReduceProcessorFactory.processors.put(reduceType, processor); |
| } |
| |
| public static ReduceProcessor getProcessor(String processorClass) throws UnknownReduceTypeException { |
| if (processors.containsKey(processorClass)) { |
| return processors.get(processorClass); |
| } else { |
| ReduceProcessor processor = null; |
| try { |
| processor = (ReduceProcessor) Class.forName(processorClass).newInstance(); |
| } catch (ClassNotFoundException e) { |
| throw new UnknownReduceTypeException("Unknown reducer class for:" + processorClass, e); |
| } catch (Exception e) { |
| throw new UnknownReduceTypeException("error constructing processor", e); |
| } |
| // TODO using a ThreadSafe/reuse flag to actually decide if we want |
| // to reuse the same processor again and again |
| register(processorClass, processor); |
| return processor; |
| } |
| |
| } |
| |
| |
| } |