I tried to use a class which implements the Serializable interface and got
the following error:
java.lang.NullPointerException
at
org.apache.hadoop.io.serializer.SerializationFactory.getSerializer(SerializationFactory.java:73)
at
org.apache.hadoop.mapred.MapTask$MapOutputBuffer.<init>(MapTask.java:759)
at
org.apache.hadoop.mapred.MapTask$NewOutputCollector.<init>(MapTask.java:487)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:575)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:305)
at org.apache.hadoop.mapred.Child.main(Child.java:170)
On Tue, Apr 27, 2010 at 12:53 PM, Farhan Husain
<[email protected]>wrote:
> Hello,
>
> I want to output a class which I have written as the value of the map
> phase. The obvious was is to implement the Writable interface but the
> problem is the class has other classes as its member properties. The
> DataInput and DataOutput interfaces used by the read and write methods of
> the Writable class do not support object serialization. Is there any other
> way I can achieve this?
>
> Thanks,
> Farhan
>
