Hadoop 运行 jar 包出现以下问题
22/09/03 00:34:34 INFO mapreduce.Job: Task Id : attempt_1662133271274_0002_m_000000_1, Status : FAILED
Error: java.lang.ClassCastException: org.apache.hadoop.io.LongWritable cannot be cast to org.apache.hadoop.io.IntWritable
Map 类 key的默认输入是 LongWritable 型,不能强转。