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.hive.hcatalog.mapreduce; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.hive.conf.HiveConf; import org.apache.hadoop.hive.ql.io.RCFileOutputFormat; import org.apache.hadoop.hive.ql.io.avro.AvroContainerOutputFormat; import org.apache.hadoop.hive.ql.io.orc.OrcConf; import org.apache.hadoop.hive.ql.io.orc.OrcOutputFormat; import org.apache.hadoop.hive.serde2.avro.AvroSerDe; import org.apache.hadoop.hive.serde2.avro.AvroSerdeUtils; import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo; import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoUtils; import org.apache.hadoop.mapred.OutputFormat; import org.apache.hive.hcatalog.data.schema.HCatFieldSchema; import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.Properties; /** * This class is a place to put all the code associated with * Special cases. If there is a corner case required to make * a particular format work that is above and beyond the generic * use, it belongs here, for example. Over time, the goal is to * try to minimize usage of this, but it is a useful overflow * class that allows us to still be as generic as possible * in the main codeflow path, and call attention to the special * cases here. * * Note : For all methods introduced here, please document why * the special case is necessary, providing a jira number if * possible. */ public class SpecialCases { static final private Log LOG = LogFactory.getLog(SpecialCases.class); /** * Method to do any file-format specific special casing while * instantiating a storage handler to write. We set any parameters * we want to be visible to the job in jobProperties, and this will * be available to the job via jobconf at run time. * * This is mostly intended to be used by StorageHandlers that wrap * File-based OutputFormats such as FosterStorageHandler that wraps * RCFile, ORC, etc. * * @param jobProperties : map to write to * @param jobInfo : information about this output job to read from * @param ofclass : the output format in use */ public static void addSpecialCasesParametersToOutputJobProperties(Map<String, String> jobProperties, OutputJobInfo jobInfo, Class<? extends OutputFormat> ofclass) { if (ofclass == RCFileOutputFormat.class) { // RCFile specific parameter jobProperties.put(HiveConf.ConfVars.HIVE_RCFILE_COLUMN_NUMBER_CONF.varname, Integer.toOctalString(jobInfo.getOutputSchema().getFields().size())); } else if (ofclass == OrcOutputFormat.class) { // Special cases for ORC // We need to check table properties to see if a couple of parameters, // such as compression parameters are defined. If they are, then we copy // them to job properties, so that it will be available in jobconf at runtime // See HIVE-5504 for details Map<String, String> tableProps = jobInfo.getTableInfo().getTable().getParameters(); for (OrcConf property : OrcConf.values()) { String propName = property.getAttribute(); if (tableProps.containsKey(propName)) { jobProperties.put(propName, tableProps.get(propName)); } } } else if (ofclass == AvroContainerOutputFormat.class) { // Special cases for Avro. As with ORC, we make table properties that // Avro is interested in available in jobconf at runtime Map<String, String> tableProps = jobInfo.getTableInfo().getTable().getParameters(); for (AvroSerdeUtils.AvroTableProperties property : AvroSerdeUtils.AvroTableProperties.values()) { String propName = property.getPropName(); if (tableProps.containsKey(propName)) { String propVal = tableProps.get(propName); jobProperties.put(propName, tableProps.get(propName)); } } Properties properties = new Properties(); properties.put("name", jobInfo.getTableName()); List<String> colNames = jobInfo.getOutputSchema().getFieldNames(); List<TypeInfo> colTypes = new ArrayList<TypeInfo>(); for (HCatFieldSchema field : jobInfo.getOutputSchema().getFields()) { colTypes.add(TypeInfoUtils.getTypeInfoFromTypeString(field.getTypeString())); } jobProperties.put(AvroSerdeUtils.AvroTableProperties.SCHEMA_LITERAL.getPropName(), AvroSerDe.getSchemaFromCols(properties, colNames, colTypes, null).toString()); for (String propName : jobProperties.keySet()) { String propVal = jobProperties.get(propName); } } } /** * Method to do any storage-handler specific special casing while instantiating a * HCatLoader * * @param conf : configuration to write to * @param tableInfo : the table definition being used */ public static void addSpecialCasesParametersForHCatLoader(Configuration conf, HCatTableInfo tableInfo) { if ((tableInfo == null) || (tableInfo.getStorerInfo() == null)) { return; } String shClass = tableInfo.getStorerInfo().getStorageHandlerClass(); if ((shClass != null) && shClass.equals("org.apache.hadoop.hive.hbase.HBaseStorageHandler")) { // NOTE: The reason we use a string name of the hive hbase handler here is // because we do not want to introduce a compile-dependency on the hive-hbase-handler // module from within hive-hcatalog. // This parameter was added due to the requirement in HIVE-7072 conf.set("pig.noSplitCombination", "true"); } } }