order订单关联输出

package one;


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.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.input.FileSplit;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class One {

    static {
        System.setProperty("hadoop.home.dir", "D:\\Studyingimportant\\hadoop-2.9.2");
    }


    public static class MyMapper extends Mapper<LongWritable, Text,Text,Text>{
        @Override
        protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
            String FileName = ((FileSplit) context.getInputSplit()).getPath().getName();
            String line = value.toString();
            String[] lineArr = line.split(",");
            if ("order.txt".equals(FileName)){
                context.write(new Text(lineArr[1]),new Text("1,"+lineArr[0]));
            }else {
                context.write(new Text(lineArr[0]),new Text("2," +lineArr[1]+","+lineArr[2]+","+lineArr[3]));
            }
        }
    }

    public static class MyReducer extends Reducer<Text,Text,Text,Text>{
        @Override
        protected void reduce(Text key, Iterable<Text> values, Context context) throws IOException, InterruptedException {
            List<String> orderDetailList = new ArrayList<>();
            List<String> itemInfoList = new ArrayList<>();

            for (Text value:values){
                String valueStr = value.toString();
                String[] valueArr = valueStr.split(",");
                if ("1".equals(valueArr[0])){
                    orderDetailList.add(valueArr[1]);
                }else {
                    itemInfoList.add(valueStr.substring(2));
                }
            }
            for (String iteminfo:itemInfoList){
                for (String orderDatail:orderDetailList){
                    context.write(new Text(orderDatail+","+key+","+iteminfo),new Text(""));
                }
            }
        }
    }

    public static void main(String[] args) throws Exception {

        //初始化一个作业
        Configuration conf = new Configuration();
        //给作业取个名字
        Job job = Job.getInstance(conf, "One");
        //输入文件路径
        FileInputFormat.addInputPaths(job,args[0]);
        //map并行计算
        job.setMapperClass(MyMapper.class);
        //shuffle流程

        //reduce计算
        job.setReducerClass(MyReducer.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(Text.class);
        //输出文件路径
        FileOutputFormat.setOutputPath(job,new Path(args[1]));
        //判断文件是否存在
        FileSystem fs = FileSystem.get(conf);
        if (fs.exists(new Path(args[1]))){
            fs.delete(new Path(args[1]),true);
        }
        //判断是否成功
        boolean b = job.waitForCompletion(true);
        System.out.println(b ? 1 : 0);

    }

}