Returning custom writables will not work. In most cases the methods return Object because the types can be many things that do not fall under a single superclass other then object. like Integer,IntWritable, Array<IntWritable>, or Map. In your case, a struct corresponds to a Map.
On Tue, May 29, 2012 at 11:08 AM, kulkarni.swar...@gmail.com <kulkarni.swar...@gmail.com> wrote: > If someone can help understand this, I would really appreciate. > > On Fri, May 25, 2012 at 3:58 PM, kulkarni.swar...@gmail.com > <kulkarni.swar...@gmail.com> wrote: >> >> I am trying to write a custom ObjectInspector extending the >> StructObjectInspector and got a little confused about the use of the >> getStructFieldData method on the inspector. Looking at the definition of the >> method: >> >> public Object getStructFieldData(Object data, StructField fieldRef); >> >> I understand that the use of this method is to retrieve the specific given >> field from the buffer. However, what I don't understand is what is it >> expected to return. I looked around the tests and related code and mostly >> stuff returned was either a LazyPrimitive or a LazyNonPrimitive, but I >> couldn't find anything that enforces this(specially given that the return >> type is a plain "Object")! Does this mean that I am free to return even my >> custom object as a return type of this method? If so, what is the guarantee >> that it will be interpreted correctly down the pipeline? >> >> Thanks, >> -- >> Swarnim > > > > > -- > Swarnim
