Pig: UDF not returning expected resultset

Question

This is the sample data on which i was working:

Peter   Wilkerson   27  M
James   Owen    26  M
Matt    Wo  30  M
Kenny   Chen    28  M

I created a simple UDF for filtering the age like this:

public class IsApplicable extends FilterFunc {

    @Override
    public Boolean exec(Tuple tuple) throws IOException {
        if(tuple == null || tuple.size() > 0){
            return false;
        }
        try {
            Object object = tuple.get(0);
            if(object == null){
                return false;
            }
            int age = (Integer)object;
            return age > 28;
        } catch (Exception e) {
            throw new IOException(e);
        }
    }

}

This is the Script I used for using this UDF:

records = LOAD '~/Documents/data.txt' AS (firstname:chararray,lastname:chararray,age:int,gender:chararray);
filtered_records = FILTER records BY com.udf.IsApplicable(age);
dump filtered_records;

Dumping does not display any record. Please let me know where I missed.

Answer 1

This is returning false for all of the rows:

if (tuple == null || tuple.size() > 0) {
    return false;
}

This is fetching the userName and not age:

Object object = tuple.get(0);

Answer 2

tuple.size() > 0 condition is always true in the if stmt, so it will never go to the try block(ie filtering logic), that is the reason you are getting empty result. Can you change the if condition like this?

     System.out.println("TupleSize="+tuple.size());
     if(tuple == null || tuple.size() < 0){
            return false;
        }

Sample debug output in console:

2015-02-13 07:40:46,994 [Thread-2] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapOnly$Map - Aliases being processed per job phase (AliasName[line,offset]): M: records[3,10],records[-1,-1],filtered_records[4,19] C:  R: 
TupleSize=1
TupleSize=1
TupleSize=1