Error: java.lang.RuntimeException: java.lang.ClassNotFoundException: Class com.mapreduce.api.WordCountDriver$WordCountMapper not found
at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:2349)
at org.apache.hadoop.mapreduce.task.JobContextImpl.getMapperClass(JobContextImpl.java:196)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:751)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341)
at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:164)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1924)
at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:158)
Caused by: java.lang.ClassNotFoundException: Class com.mapreduce.api.WordCountDriver$WordCountMapper not found
at org.apache.hadoop.conf.Configuration.getClassByName(Configuration.java:2255)
at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:2347)
I face the above issue when running the below program in AWS , Cloudera instance
public class WordCountDriver extends Configured implements Tool {
public static void main(String[] args) throws Exception {
int returnStatus = ToolRunner.run(new Configuration(), new WordCountDriver(), args);
System.exit(returnStatus);
}
public int run(String[] args) throws IOException, InterruptedException, ClassNotFoundException {
Configuration configuration = new Configuration();
String[] files = new GenericOptionsParser(configuration, args).getRemainingArgs();
Job job = Job.getInstance(configuration, "WordCount MR");
job.setJarByClass(WordCountDriver.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.class);
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(IntWritable.class);
job.setMapperClass(WordCountMapper.class);
job.setReducerClass(WordCountReducer.class);
FileInputFormat.addInputPath(job, new Path(files[0]));
FileOutputFormat.setOutputPath(job, new Path(files[1]));
return (job.waitForCompletion(true)?0:1);
}
public static class WordCountMapper extends Mapper<LongWritable, Text, Text, IntWritable> {
private IntWritable ONE = new IntWritable(1);
@Override
protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
String[] records = value.toString().split(" ");
for (String record: records) {
context.write(new Text(record), ONE);
}
}
}
public static class WordCountReducer extends Reducer<Text, IntWritable, Text, IntWritable> {
@Override
protected void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException {
int count = 0;
for (IntWritable value: values) {
count += value.get();
}
context.write(key, new IntWritable(count));
}
}
}
