如何在hadoop中从输入文件路径、外部映射器和减速器(即驱动程序类)获取文件名

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.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;

public class FileNameExtractor {
  
  public static class FileNameMapper extends Mapper<LongWritable, Text, Text, Text> {
    
    @Override
    protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
      // 获取输入文件路径
      Path filePath = ((FileSplit) context.getInputSplit()).getPath();
      String fileName = filePath.getName();
      
      // 将文件名作为键，输入内容作为值输出
      context.write(new Text(fileName), value);
    }
  }
  
  public static class FileNameReducer extends Reducer<Text, Text, Text, Text> {
    
    @Override
    protected void reduce(Text key, Iterable<Text> values, Context context) throws IOException, InterruptedException {
      // 获取文件名
      String fileName = key.toString();
      
      // 处理输入内容
      // ...
      
      // 输出结果
      context.write(key, new Text("Processed data"));
    }
  }
  
  public static void main(String[] args) throws Exception {
    Configuration conf = new Configuration();
    Job job = Job.getInstance(conf, "FileNameExtractor");
    job.setJarByClass(FileNameExtractor.class);
    job.setMapperClass(FileNameMapper.class);
    job.setReducerClass(FileNameReducer.class);
    job.setOutputKeyClass(Text.class);
    job.setOutputValueClass(Text.class);
    FileInputFormat.addInputPath(job, new Path(args[0]));
    FileOutputFormat.setOutputPath(job, new Path(args[1]));
    System.exit(job.waitForCompletion(true) ? 0 : 1);
  }
}