Big data case: MapReduce's map end table merge (Distributedcache)

Code download address: https://github.com/tazhigang/big-data-github.git

I. preliminary preparation

Since this case is optimized on the basis of case 6, please refer to case 6 for requirements and data input and output; for the first time, you need to copy the pd.txt file in the root directory of the J disk of the local computer for reference.
This case only needs to upload order.txt to HDFS - "/ user / Hadoop / order" productv2 / input "

Two, code

DistributedCacheDriver.java

package com.ittzg.hadoop.orderproductv2;

import com.ittzg.hadoop.orderproduct.OrderAndProductBean;
import org.apache.commons.lang.StringUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
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.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URI;
import java.util.HashMap;
import java.util.Map;

/**
 * @email: tazhigang095@163.com
 * @author: ittzg
 * @date: 2019/7/6 20:46
 */
public class DistributedCacheDriver {
    public static class DistributedCacheMapper extends Mapper<LongWritable,Text,OrderAndProductBean,NullWritable>{
        Map<String,String> map = new HashMap<String,String>();
        @Override
        protected void setup(Context context) throws IOException, InterruptedException {
            //Get cached files in
            BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream("j:/pd.txt")));
            String line;
            while(StringUtils.isNotEmpty(line = reader.readLine())){
                // 2 cutting
                String[] fields = line.split("\t");
                // 3 cache data to collection
                System.out.println(fields[0]+":"+fields[0].trim().length());
                map.put(fields[0], fields[1]);
            }
            // 4 off flow
            reader.close();
        }
        OrderAndProductBean orderAndProductBean= new OrderAndProductBean();
        @Override
        protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
            System.out.println(map.toString());
            String line = value.toString();
            String[] split = line.split("\t");
            orderAndProductBean.setOrderId(split[0]);
            orderAndProductBean.setPdId(split[1]);
            orderAndProductBean.setAccount(split[2]);
            orderAndProductBean.setPdName(map.get(split[1]));
            orderAndProductBean.setFlag("0");
            context.write(orderAndProductBean,NullWritable.get());
        }
    }
    public static class OrderProDuctReduce extends Reducer<OrderAndProductBean,NullWritable,OrderAndProductBean,NullWritable>{
        @Override
        protected void reduce(OrderAndProductBean key, Iterable<NullWritable> values, Context context) throws IOException, InterruptedException {
            context.write(key,NullWritable.get());
        }
    }

    public static void main(String[] args) throws Exception{
        // Set I / O path
        String input = "hdfs://hadoop-ip-101:9000/user/hadoop/order_productv2/input";
        String output = "hdfs://hadoop-ip-101:9000/user/hadoop/order_productv2/output";
        Configuration conf = new Configuration();
        conf.set("mapreduce.app-submission.cross-platform","true");
        Job job = Job.getInstance(conf);
        //
        job.setJar("F:\\big-data-github\\hadoop-parent\\hadoop-order-product\\target\\hadoop-order-product-1.0-SNAPSHOT.jar");

        job.setMapperClass(DistributedCacheMapper.class);
        job.setReducerClass(OrderProDuctReduce.class);

        job.setMapOutputKeyClass(OrderAndProductBean.class);
        job.setMapOutputValueClass(NullWritable.class);

        job.setOutputKeyClass(OrderAndProductBean.class);
        job.setOutputValueClass(NullWritable.class);
        // 6 load cache data
        job.addCacheFile(new URI("file:/j:/pd.txt"));

        FileSystem fs = FileSystem.get(new URI("hdfs://hadoop-ip-101:9000"),conf,"hadoop");
        Path outPath = new Path(output);
        if(fs.exists(outPath)){
            fs.delete(outPath,true);
        }
        FileInputFormat.addInputPath(job,new Path(input));
        FileOutputFormat.setOutputPath(job,outPath);

        boolean bool = job.waitForCompletion(true);
        System.exit(bool?0:1);
    }
}