hadoop学习笔记之数据排序

package cn.yws;import java.io.IOException;import org.apache.hadoop.conf.Configuration;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.Mapper;import org.apache.hadoop.mapreduce.Reducer;import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;import org.apache.hadoop.util.GenericOptionsParser;public class MySort {public static class MyMap extends Mapper<Object, Text, IntWritable, IntWritable>{private static IntWritable data=new IntWritable();@Overrideprotected void map(Object key, Text value,org.apache.hadoop.mapreduce.Mapper.Context context)throws IOException, InterruptedException {String line=value.toString();data.set(Integer.parseInt(line));context.write(data, new IntWritable(1));//super.map(key, value, context);}}public static class MyReduce extends Reducer<IntWritable, IntWritable, IntWritable, IntWritable>{private static IntWritable linenum=new IntWritable();protected void reduce(IntWritable key, Iterable<IntWritable> values,org.apache.hadoop.mapreduce.Reducer.Context context)throws IOException, InterruptedException {//super.reduce(key, values, context);for(IntWritable val:values){context.write(linenum, key);linenum=new IntWritable(linenum.get()+1);}}}public static void main(String[] args) throws Exception {Configuration configuration=new Configuration();configuration.set("mapred.job.tracker", "192.168.1.9:9001");String[] ioArgs=new String[]{"sort_in","sort_out"};if(args.length==2){ioArgs=args;}String otherArgs[]=new GenericOptionsParser(configuration,ioArgs).getRemainingArgs();if(otherArgs.length!=2){System.err.println("Usage: Data MySort <in> <out>");System.exit(2);}Job job=new Job(configuration,"data sort");job.setJarByClass(MySort.class);job.setMapperClass(MyMap.class);job.setCombinerClass(MyReduce.class);job.setReducerClass(MyReduce.class);job.setOutputKeyClass(IntWritable.class);job.setOutputValueClass(IntWritable.class);FileInputFormat.addInputPath(job, new Path(otherArgs[0]));FileOutputFormat.setOutputPath(job, new Path(otherArgs[1]));System.exit(job.waitForCompletion(true)?0:1);}}

sort_in

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