sorry, i have found this method in the javadoc of hadoop0.20.1, but i met a new problem when i run the same example
r...@master:/home/zhoufeng/newdisk/hadoop-0.20.1# bin/hadoop jar /home/zhoufeng/newdisk/result/trunk/core/target/mahout-core-0.3-SNAPSHOT.job org.apache.mahout.cf.taste.hadoop.SlopeOnePrefsToDiffsJob -i r.txt -o output 09/10/29 15:37:06 WARN mapred.JobClient: Use GenericOptionsParser for parsing the arguments. Applications should implement Tool for the same. 09/10/29 15:37:06 WARN mapred.JobClient: No job jar file set. User classes may not be found. See JobConf(Class) or JobConf#setJar(String). Exception in thread "main" java.lang.RuntimeException: java.lang.RuntimeException: class org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat not org.apache.hadoop.mapred.OutputFormat at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:840) at org.apache.hadoop.mapred.JobConf.getOutputFormat(JobConf.java:422) at org.apache.hadoop.mapred.JobClient.submitJobInternal(JobClient.java:772) at org.apache.hadoop.mapreduce.Job.submit(Job.java:432) at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:447) at org.apache.mahout.cf.taste.hadoop.SlopeOnePrefsToDiffsJob.main(SlopeOnePrefsToDiffsJob.java:86) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.hadoop.util.RunJar.main(RunJar.java:156) Caused by: java.lang.RuntimeException: class org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat not org.apache.hadoop.mapred.OutputFormat at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:834) ... 10 more Which version of hadoop should I choose? thanks
