Mapper的角色是读取输入数据,解析电影的类型,并输出结果。 importorg.apache.hadoop.io.LongWritable;importorg.apache.hadoop.io.Text;importorg.apache.hadoop.mapreduce.Mapper;importjava.io.IOException;publicclassMovieMapperextendsMapper<LongWritable,Text,Text,LongWritable>{privatefinalstaticLongWritableone=newLongWrita...