I used classes generated by sqoop as Key-Value, and set OutputFormat to
SequenceFileOutputFormat, and the error occurred.
However, when I simply changed the Key-Value to Text, and OutputFormat to
TextOutputFormat, it worked!
SqoopGenClass value = ....;
context.write(value, NullWritable.get());
=====>>>>
context.write(new Text(value.toString()), NullWritable.get());
Our hadoop version is 0.20.2,that's too old so I gusss this is the cause.
-----邮件原件-----
发件人: Jarek Jarcec Cecho [mailto:[email protected]]
发送时间: 12 August 2013 08:35
收件人: [email protected]
主题: Re: sqoop generate java class in old mapreduce API?
Hi Yongbo,
I believe that the writable itself should be independent on the new vs. old
mapreduce API. Would you mind sharing more details about your use case?
Maybe a small code example reproducing the issue could help us move forward.
Jarcec
On Thu, Aug 08, 2013 at 09:10:50PM +0800, Wu YongBo wrote:
> Hi All,
>
>
>
> I am using a java class generated by sqoop(1.4.2), and I get the
> following error:
>
>
>
> 2013-08-08 20:43:10,854 WARN org.apache.hadoop.mapred.TaskTracker:
> Error running child
>
> java.lang.ClassCastException: class
> com.a.semv.io.semreportbase_keyword
>
> at java.lang.Class.asSubclass(Class.java:3018)
>
> at
> org.apache.hadoop.mapred.JobConf.getOutputKeyComparator(JobConf.java:5
> 99)
>
> at
> org.apache.hadoop.mapred.MapTask$MapOutputBuffer.<init>(MapTask.java:7
> 91)
>
> at
> org.apache.hadoop.mapred.MapTask$NewOutputCollector.<init>(MapTask.jav
> a:524)
>
> at
> org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:613)
>
> at org.apache.hadoop.mapred.MapTask.run(MapTask.java:305)
>
> at org.apache.hadoop.mapred.Child.main(Child.java:170)
>
>
>
> My job is written in mapreduce new API.
>
> My hadoop version:0.20.2
>
>
>
> Thanks,
>
> Yongbo
>
>
>
