Java tutorial
/* * Copyright 2010-2011 the original author or authors. * * 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 cn.lhfei.hadoop.ch02; import java.io.IOException; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.IntWritable; 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.output.FileOutputFormat; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * @version 0.1 * * @author Hefei Li * * @since Oct 20, 2014 */ public class MaxTemperature { private static final Logger log = LoggerFactory.getLogger(MaxTemperature.class); public static void main(String[] args) { log.debug("Logging ... "); if (args.length != 2) { System.err.println("Usage: MaxTemperature <input path> <output path>"); System.exit(-1); } try { Job job = new Job(); job.setJarByClass(MaxTemperature.class); job.setJobName("Max temperature"); FileInputFormat.addInputPath(job, new Path(args[0])); FileOutputFormat.setOutputPath(job, new Path(args[1])); /*FileInputFormat.addInputPath(job, new Path(INPUT)); FileOutputFormat.setOutputPath(job, new Path(OUTPUT));*/ job.setMapperClass(MaxTemperatureMapper.class); job.setReducerClass(MaxTemperatureReducer.class); job.setOutputKeyClass(Text.class); job.setOutputValueClass(IntWritable.class); System.exit(job.waitForCompletion(true) ? 0 : 1); } catch (IllegalStateException e) { log.error(e.getMessage(), e); } catch (IllegalArgumentException e) { log.error(e.getMessage(), e); } catch (ClassNotFoundException e) { log.error(e.getMessage(), e); } catch (IOException e) { log.error(e.getMessage(), e); } catch (InterruptedException e) { log.error(e.getMessage(), e); } } private static final String INPUT = "input/ncdc/sample.txt"; private static final String OUTPUT = "output"; }