SortedPriceName排序代码（基于mapreduce处理逻辑）

SortedPriceName排序代码（基于mapreduce处理逻辑）

---

mapper.java

---

package com.doggie.test;import org.apache.hadoop.io.LongWritable;import org.apache.hadoop.io.Text;import org.apache.hadoop.mapreduce.Mapper;import org.apache.hadoop.mapreduce.lib.input.FileSplit;import java.io.IOException;/** * Created by root on 5/25/16. */public class mapper extends Mapper<Object,Text,LongWritable,Text> {    public void map(Object key,Text value,Context context)        throws IOException,InterruptedException{        String fileName = ((FileSplit)context.getInputSplit()).getPath().toString();        String valueString= value.toString();        String[] items=valueString.split(" ");        LongWritable outputKey = null;        Text outputValue=null;        if(fileName.contains("price")){            outputKey = new LongWritable(Long.valueOf(items[0]));            outputValue = new Text(items[1]);        }else{            outputKey = new LongWritable(Long.valueOf(items[1]));            outputValue = new Text("name" + items[0]);        }        context.write(outputKey,outputValue);    }}---reducer.java---package com.doggie.test;import org.apache.hadoop.io.LongWritable;import org.apache.hadoop.io.Text;import org.apache.hadoop.mapreduce.Reducer;import org.apache.hadoop.mapreduce.lib.input.FileSplit;import java.io.IOException;import java.util.TreeSet;/** * Created by root on 5/25/16. */public class reducer extends Reducer<LongWritable,Text,Text,LongWritable> {    public void reduce(LongWritable key, Iterable<Text>values, Context context)            throws IOException, InterruptedException {        Text itemName = null;        TreeSet<LongWritable> queue = new TreeSet<LongWritable>();        for (Text val : values){            if(val.toString().startsWith("name")){                String realName = val.toString().substring(4);                itemName = new Text(realName);            }else{                LongWritable price = new LongWritable(Long.valueOf(val.toString()));                queue.add(price);            }        }        for (LongWritable val : queue) {            context.write(itemName, val);        }    }}---main---package com.doggie.mtest;import com.doggie.test.mapper;import com.doggie.test.reducer;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.fs.Path;import org.apache.hadoop.io.LongWritable;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.TextInputFormat;import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;import org.apache.hadoop.util.GenericOptionsParser;/** * Created by root on 5/25/16. */public class Homework {    public static void main(String[] args) throws Exception {        Configuration conf = new Configuration();        String[] otherArgs = new GenericOptionsParser(conf, args)                .getRemainingArgs();        if (otherArgs.length != 2) {            System.err.println("Usage: homework");            System.exit(2);        }        //conf.setInt("mapred.task.timeout",100);        Job job = new Job(conf, "homework");        job.setInputFormatClass(TextInputFormat.class);        job.setJarByClass(Homework.class);        job.setMapperClass(mapper.class);        job.setReducerClass(reducer.class);        job.setMapOutputKeyClass(LongWritable.class);        job.setMapOutputValueClass(Text.class);        job.setOutputKeyClass(Text.class);        job.setOutputValueClass(LongWritable.class);        job.setNumReduceTasks(1);        FileInputFormat.addInputPath(job, new Path(otherArgs[0]));        FileOutputFormat.setOutputPath(job, new Path(otherArgs[1]));        System.exit(job.waitForCompletion(true) ? 0 : 1);    }}[两个输入文件样本](https://yunpan.cn/cSDYkqREN9N3H  访问密码 ff1b)