Java tutorial
/** * 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.hama.bsp.message.compress; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.io.Writable; import org.apache.hadoop.util.ReflectionUtils; public class BSPMessageCompressorFactory<M extends Writable> { public static final String COMPRESSION_CODEC_CLASS = "hama.messenger.compression.class"; /** * Returns a compressor via reflection based on what was configured. * * @param conf * @return a compressor that was configured. */ @SuppressWarnings("unchecked") public BSPMessageCompressor<M> getCompressor(Configuration conf) { if (conf.get(COMPRESSION_CODEC_CLASS) != null) { try { return (BSPMessageCompressor<M>) ReflectionUtils.newInstance(conf.getClassByName( conf.get(COMPRESSION_CODEC_CLASS, Bzip2Compressor.class.getCanonicalName())), conf); } catch (ClassNotFoundException e) { e.printStackTrace(); } } return null; } }