Java UDF on Hadoop input parameter -- call from Pig on Hadoop

Question

If I have the following data structure (a relation) in Pig and I want to pass it to a Java UDF, wondering what should be the related Java data type of the input parameter?

(student relation is a bag, schema is ID as int, a tuple contains an interest bag and a classes bag).

student: {id: int,(interest: {(value: chararray)},classes: {(value: chararray)})}

thanks in advance, Lin

Answer 1

I think it can be done as shown below.

 public class BagUdf extends EvalFunc<DataBag> {

public <returnType> exec(Tuple input) throws IOException {
//iterate over the bag elements
for (Tuple t : (DataBag)input.get(0)) {
     // process tuple t
}
return returnVal;
}

Please refer to this link