mapreduce排序
1010037 100 1010102 100 1010152 97 1010178 96 1010280 104 1010320 103 1010510 104 1010603 96 1010637 97
源代码:
package mapreduce; import java.io.IOException; import java.util.StringTokenizer; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.IntWritable; import org.apache.hadoop.io.NullWritable; 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.Reducer.Context; import org.apache.hadoop.mapreduce.lib.input.FileInputFormat; import org.apache.hadoop.mapreduce.lib.input.TextInputFormat; import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat; import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat; import mapreduce.WordCount.MyMapper; import mapreduce.WordCount.MyReducer; public class OneSort { public static class Map extends Mapper<Object, Text, IntWritable,Text > { private static Text goods= new Text(); private static IntWritable num=new IntWritable(); public void map(Object key, Text value, Context context) throws IOException, InterruptedException { StringTokenizer itr = new StringTokenizer(value.toString()); while (itr.hasMoreTokens()) { String line = itr.nextToken(); String arr[]=line.split(" "); num.set(Integer.parseInt(arr[1])); goods.set(arr[0]); context.write(num,goods); } } } public static class Reduce extends Reducer<IntWritable,Text,IntWritable, Text> { private static IntWritable result=new IntWritable(); public void reduce(IntWritable key, Iterable<Text> values, Context context) throws IOException, InterruptedException { for(Text val:values) { context.write(key, val); } } } public static void main(String[] args) throws Exception { Configuration conf = new Configuration(); System.out.println("start"); Job job = new Job(conf, "OneSort"); job.setJarByClass(OneSort.class); job.setMapperClass(Map.class); job.setReducerClass(Reduce.class); job.setOutputKeyClass(IntWritable.class); job.setOutputValueClass(Text.class); job.setInputFormatClass(TextInputFormat.class); job.setOutputFormatClass(TextOutputFormat.class); Path in = new Path("hdfs://localhost:9000/mymapreduce4/in/goods_visit1"); Path out = new Path("hdfs://localhost:9000/mymapreduce4/out"); FileInputFormat.addInputPath(job, in); FileOutputFormat.setOutputPath(job, out); System.exit(job.waitForCompletion(true) ? 0 : 1); } }
排序结果:
96 1010603 96 1010178 97 1010637 97 1010152 100 1010102 100 1010037 103 1010320 104 1010510 104 1010280
作者:我是一个粉刷匠
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