MapReduce 只有Map阶段，写出到pc端

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package ProOrder2;import java.io.BufferedReader;import java.io.FileInputStream;import java.io.FileReader;import java.io.IOException;import java.io.InputStreamReader;import java.util.HashMap;import org.apache.hadoop.io.LongWritable;import org.apache.hadoop.io.NullWritable;import org.apache.hadoop.io.Text;import org.apache.hadoop.mapreduce.Mapper;public class ProOrdMapper2 extends Mapper<LongWritable, Text, Text, NullWritable>{    HashMap<String, String> map = new HashMap<String,String>();    @Override    protected void setup(Context context)            throws IOException, InterruptedException {        BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream("E:/study/bigdata/hadoop/第8天/product/product.txt")));        String line="";        String pId="";        String pName="";        while((line=br.readLine())!=null){            String[] strs = line.split("\t");            pId = strs[0];            pName = strs[3];            map.put(pId, pName);        }        br.close();    }    @Override    protected void map(LongWritable key, Text value, Context context)            throws IOException, InterruptedException {        String[] split = value.toString().split("\t");        String orderId = split[2];        Text text = new Text(value + "\t" +map.get(orderId));        context.write(text, NullWritable.get());     }}

只有map阶段也是可以直接输出的

package ProOrder2;import java.io.IOException;import java.net.URI;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.fs.Path;import org.apache.hadoop.io.NullWritable;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;public class ProOrdDriver2 {    public static void main(String[] args) throws Exception  {        String path1="";        String path2="";        if(args.length==2){            path1 = args[0];            path2 = args[1];        }else{            return;        }        Configuration conf = new Configuration();        Job job = Job.getInstance(conf);        job.setJarByClass(ProOrdDriver2.class);        job.setMapperClass(ProOrdMapper2.class);        job.setOutputKeyClass(Text.class);        job.setOutputValueClass(NullWritable.class);        FileInputFormat.setInputPaths(job, newPath(path1));        FileOutputFormat.setOutputPath(job, new Path(path2));        job.addCacheFile(new URI("file:///E:/study/bigdata/hadoop/第8天/product/product.txt"));        boolean res = job.waitForCompletion(true);        System.exit(res?0:1);    }}

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