Hadoop and Custom Writable Issue - hadoop

Question

I am using Hadoop 2.7 and I have got an issue when using a custom Writable "TextPair" (page 104 of the Definitive Guide). Basically, my program works fine when I am using just Text whereas it outputs "test.TextTuple#3b86249a test.TextTuple#63cd18fd" when using the TextPair.
Please, Any idea of what is wrong with my code (below)?
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Mapper1:
public class KWMapper extends Mapper<LongWritable, Text, TextTuple, TextTuple> {
#Override
public void map(LongWritable k, Text v, Mapper.Context c) throws IOException, InterruptedException {
String keywordRelRecord[] = v.toString().split(",");
String subTopicID = keywordRelRecord[0];
String paperID = keywordRelRecord[1];
//set the KEY
TextTuple key = new TextTuple();
key.setNaturalKey(new Text(subTopicID));
key.setSecondaryKey(new Text("K"));
//set the VALUE
TextTuple value = new TextTuple();
value.setNaturalKey(new Text(paperID));
value.setSecondaryKey(new Text("K"));
c.write(key, value);
}
Mapper2:
public class TDMapper extends Mapper<LongWritable, Text, TextTuple, TextTuple> {
#Override
public void map(LongWritable k, Text v, Mapper.Context c) throws IOException, InterruptedException {
String topicRecord[] = v.toString().split(",");
String superTopicID = topicRecord[0];
String subTopicID = topicRecord[1].substring(1, topicRecord[1].length() - 1);
TextTuple key = new TextTuple();
key.setNaturalKey(new Text(subTopicID));
key.setSecondaryKey(new Text("T"));
TextTuple value = new TextTuple();
value.setNaturalKey(new Text(superTopicID));
value.setSecondaryKey(new Text("T"));
c.write(key, value);
}
REDUCER :
public class TDKRReducer extends Reducer<TextTuple, TextTuple, Text, Text>{
public void reduce(TextTuple k, Iterable<TextTuple> values, Reducer.Context c) throws IOException, InterruptedException{
for (TextTuple val : values) {
c.write(k.getNaturalKey(), val.getNaturalKey());
}
}
}
DRIVER:
public class TDDriver {
public static void main(String args[]) throws IOException, InterruptedException, ClassNotFoundException {
// This class support the user for the configuration of the execution;
Configuration confStage1 = new Configuration();
Job job1 = new Job(confStage1, "TopDecKeywordRel");
// Setting the driver class
job1.setJarByClass(TDDriver.class);
// Setting the input Files and processing them using the corresponding mapper class
MultipleInputs.addInputPath(job1, new Path(args[0]), TextInputFormat.class, TDMapper.class);
MultipleInputs.addInputPath(job1, new Path(args[1]), TextInputFormat.class, KWMapper.class);
job1.setMapOutputKeyClass(TextTuple.class);
job1.setMapOutputValueClass(TextTuple.class);
// Setting the Reducer Class;
job1.setReducerClass(TDKRReducer.class);
// Setting the output class for the Key-value pairs
job1.setOutputKeyClass(Text.class);
job1.setOutputValueClass(Text.class);
// Setting the output file
Path outputPA = new Path(args[2]);
FileOutputFormat.setOutputPath(job1, outputPA);
// Submitting the Job Monitoring the execution of the Job
System.exit(job1.waitForCompletion(true) ? 0 : 1);
//conf.setPartitionerClass(CustomPartitioner.class);
}
}
CUSTOM VARIABLE
public class TextTuple implements Writable, WritableComparable<TextTuple> {
private Text naturalKey;
private Text secondaryKey;
public TextTuple() {
this.naturalKey = new Text();
this.secondaryKey = new Text();
}
public void setNaturalKey(Text naturalKey) {
this.naturalKey = naturalKey;
}
public void setSecondaryKey(Text secondaryKey) {
this.secondaryKey = secondaryKey;
}
public Text getNaturalKey() {
return naturalKey;
}
public Text getSecondaryKey() {
return secondaryKey;
}
#Override
public void write(DataOutput out) throws IOException {
naturalKey.write(out);
secondaryKey.write(out);
}
#Override
public void readFields(DataInput in) throws IOException {
naturalKey.readFields(in);
secondaryKey.readFields(in);
}
//This comparator controls the sort order of the keys.
#Override
public int compareTo(TextTuple o) {
// comparing the naturalKey
int compareValue = this.naturalKey.compareTo(o.naturalKey);
if (compareValue == 0) {
compareValue = this.secondaryKey.compareTo(o.secondaryKey);
}
return -1 * compareValue;
}
}