编写MapReduce :统计每个关键词，所在文件及，第几行出现了多少次

import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.HashMap;
import java.util.Map;

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.InputSplit;
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;

//统计每个关键词在每个文档中，第几行出现了多少次

public class kaoshi1 {
    private static int count1 =0;
    private static int count2 =0;
    static class MyMapper extends Mapper<LongWritable, Text, Text, Text>{
        Text mk=new Text();
        Text mv=new Text();
        String filename="";

        @Override
            //setup job任务运行时加载一次，可以获取文件信息
        protected void setup(Mapper.Context context)
                throws IOException, InterruptedException {
            //通过文件的切片信息，获取文件名
            InputSplit insplit = context.getInputSplit();
            FileSplit fs=(FileSplit)insplit;
            filename = fs.getPath().getName();
        }

        @Override
        protected void map(LongWritable key, 
                Text value,
                Context context)
                throws IOException, InterruptedException {
            Map word = new HashMap<>();//先创建一个map集合用于统计所在行的相同单词出现个数

            //liangchaowei love liujialing
            String[] sp = value.toString().split(" ");
            if(filename.startsWith("mapreduce-4-1.txt")){//先判断访问的是文件
                count1++;                               //单词所在的文件中的行号
                for(String v:sp){
                    if(word.containsKey(v)){            //判断是否添加过
                        word.put(v,word.get(v)+1);      //所在行的单词个数
                    }else{
                        word.put(v, 1);
                    }
                    System.out.println(count1+"----------------");
                }
                for(String k:word.keySet()){
                    mk.set(k);
                    mv.set(filename+":"+count1+","+word.get(k));//将文件名：行号，出现次数封装当value中
                    System.out.println(word.get(k));
                    context.write(mk, mv);
                }
            }else{                                              //与上同理
                count2++;
                for(String v:sp){
                    if(word.containsKey(v)){
                        word.put(v,word.get(v)+1);
                    }else{
                        word.put(v, 1);
                    }
                }
                for(String k:word.keySet()){
                    mk.set(k);
                    mv.set(filename+":"+count2+","+word.get(k));
                    System.out.println(word.get(k));
                    context.write(mk, mv);

                }
            }
        }
    }

    static class MyReducer extends Reducer<Text, Text, Text, Text>{
        Text outValue = new Text();
        String[] sp;
        @Override
        protected void reduce(Text key, 
                Iterable values, 
                Reducer.Context context)
                throws IOException, InterruptedException {
            StringBuffer sb = new StringBuffer();               //创建一个包装类
            //txt.1:1   txt.1:1:2
            System.out.println(key+"--------------++++++++++++");
            for(Text v:values){
                String[] sp = v.toString().split(":");              //测试数据用
                sb.append(v.toString()+"\t");       //将values内容进行拼接
                System.out.println(sp[0]);                  //测试是否取到数据
            }
            outValue.set(sb.toString());
            context.write(key, outValue);
        }
    }

    public static void main(String[] args) throws IOException, URISyntaxException, ClassNotFoundException, InterruptedException {
        //本地运行添加映射
        System.setProperty("HADOOP_USER_NAME", "hadoop");
        //添加配置文件
        Configuration conf = new Configuration();
        Job job = Job.getInstance(conf);                //创建Job任务

        job.setJarByClass(kaoshi1.class);               //jar运行主类（驱动类driver）

        job.setMapperClass(MyMapper.class);             //指定mapper加载的类
        job.setReducerClass(MyReducer.class);           //指定reducer加载的类

        job.setOutputKeyClass(Text.class);              //指定任务的输出的key类型
        job.setOutputValueClass(Text.class);            //指定任务的输出的value类型

        FileInputFormat.addInputPath(job, new Path("hdfs://hadoop01:9000/ksin02"));//指定加载路径

        FileSystem fs = FileSystem.get(new URI("hdfs://hadoop01:9000"), conf);//获取hdfs的文件系统路径--对象

        Path path = new Path("/ksout05");//输出结果文件路径     
        if(fs.exists(path)){                                //防止目录存在，启动失败
            fs.delete(path,true);
        }
        FileOutputFormat.setOutputPath(job, path);          //指定输出路径---（目录不能存在）
        job.waitForCompletion(true);                        //是否打印日志

    }

}