The method setMapperClass(Class<? extends Mapper>) in the type Job is not applicable for the arguments (Class<WordCountMapper>)
时间: 2024-06-13 11:06:07 浏览: 17
这个错误通常是由于您的Mapper类没有继承自org.apache.hadoop.mapreduce.Mapper类而导致的。请确保您的WordCountMapper类继承自Mapper类,并且使用正确的import语句。以下是一个示例代码片段,可以帮助您更好地理解如何使用setMapperClass方法:
```java
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.IntWritable;
public class WordCount {
public static void main(String[] args) throws Exception {
Job job = new Job();
job.setJarByClass(WordCount.class);
job.setJobName("Word Count");
job.setMapperClass(WordCountMapper.class);
job.setReducerClass(WordCountReducer.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.class);
// ...
}
}
class WordCountMapper extends Mapper<Object, Text, Text, IntWritable> {
// ...
}
```