Java tutorial
/* * Copyright 2013-2014 eBay Software Foundation * * 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 com.kylinolap.job.hadoop.invertedindex; import java.io.File; import java.io.IOException; import org.apache.commons.cli.Options; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.NullWritable; import org.apache.hadoop.io.ShortWritable; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.Job; import org.apache.hadoop.mapreduce.lib.input.FileInputFormat; import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat; import org.apache.hadoop.mapreduce.lib.input.TextInputFormat; import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat; import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat; import org.apache.hadoop.util.ToolRunner; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.kylinolap.common.KylinConfig; import com.kylinolap.job.constant.BatchConstants; import com.kylinolap.job.hadoop.AbstractHadoopJob; import com.kylinolap.metadata.MetadataManager; import com.kylinolap.metadata.model.schema.ColumnDesc; import com.kylinolap.metadata.model.schema.TableDesc; /** * @author yangli9 */ public class IIDistinctColumnsJob extends AbstractHadoopJob { protected static final Logger log = LoggerFactory.getLogger(IIDistinctColumnsJob.class); @Override public int run(String[] args) throws Exception { Options options = new Options(); try { options.addOption(OPTION_JOB_NAME); options.addOption(OPTION_TABLE_NAME); options.addOption(OPTION_INPUT_PATH); options.addOption(OPTION_INPUT_FORMAT); options.addOption(OPTION_INPUT_DELIM); options.addOption(OPTION_OUTPUT_PATH); parseOptions(options, args); job = Job.getInstance(getConf(), getOptionValue(OPTION_JOB_NAME)); String tableName = getOptionValue(OPTION_TABLE_NAME).toUpperCase(); Path input = new Path(getOptionValue(OPTION_INPUT_PATH)); String inputFormat = getOptionValue(OPTION_INPUT_FORMAT); String inputDelim = getOptionValue(OPTION_INPUT_DELIM); Path output = new Path(getOptionValue(OPTION_OUTPUT_PATH)); // ---------------------------------------------------------------------------- System.out.println("Starting: " + job.getJobName()); setupMapInput(input, inputFormat, inputDelim); setupReduceOutput(output); // pass table and columns MetadataManager metaMgr = MetadataManager.getInstance(KylinConfig.getInstanceFromEnv()); TableDesc table = metaMgr.getTableDesc(tableName); job.getConfiguration().set(BatchConstants.TABLE_NAME, tableName); job.getConfiguration().set(BatchConstants.TABLE_COLUMNS, getColumns(table)); return waitForCompletion(job); } catch (Exception e) { printUsage(options); log.error(e.getLocalizedMessage(), e); return 2; } } private String getColumns(TableDesc table) { StringBuilder buf = new StringBuilder(); for (ColumnDesc col : table.getColumns()) { if (buf.length() > 0) buf.append(","); buf.append(col.getName()); } return buf.toString(); } private void setupMapInput(Path input, String inputFormat, String inputDelim) throws IOException { FileInputFormat.setInputPaths(job, input); File JarFile = new File(KylinConfig.getInstanceFromEnv().getKylinJobJarPath()); if (JarFile.exists()) { job.setJar(KylinConfig.getInstanceFromEnv().getKylinJobJarPath()); } else { job.setJarByClass(this.getClass()); } if ("textinputformat".equalsIgnoreCase(inputFormat) || "text".equalsIgnoreCase(inputFormat)) { job.setInputFormatClass(TextInputFormat.class); } else { job.setInputFormatClass(SequenceFileInputFormat.class); } if ("t".equals(inputDelim)) { inputDelim = "\t"; } else if ("177".equals(inputDelim)) { inputDelim = "\177"; } if (inputDelim != null) { job.getConfiguration().set(BatchConstants.INPUT_DELIM, inputDelim); } job.setMapperClass(IIDistinctColumnsMapper.class); job.setCombinerClass(IIDistinctColumnsCombiner.class); job.setMapOutputKeyClass(ShortWritable.class); job.setMapOutputValueClass(Text.class); } private void setupReduceOutput(Path output) throws IOException { job.setReducerClass(IIDistinctColumnsReducer.class); job.setOutputFormatClass(SequenceFileOutputFormat.class); job.setOutputKeyClass(NullWritable.class); job.setOutputValueClass(Text.class); FileOutputFormat.setOutputPath(job, output); job.getConfiguration().set(BatchConstants.OUTPUT_PATH, output.toString()); job.setNumReduceTasks(1); deletePath(job.getConfiguration(), output); } public static void main(String[] args) throws Exception { IIDistinctColumnsJob job = new IIDistinctColumnsJob(); int exitCode = ToolRunner.run(job, args); System.exit(exitCode); } }