@Override
public Collection<Writable> next() {
Text t = (Text) super.next().iterator().next();
String val = new String(t.getBytes());
Collection<Writable> ret = new ArrayList<>();
StringTokenizer tok;
int index, max;
String col;
double value;
// actual data
try {
// determine max index
max = 0;
tok = new StringTokenizer(val, " \t");
tok.nextToken(); // skip class
while (tok.hasMoreTokens()) {
col = tok.nextToken();
// finished?
if (col.startsWith("#")) break;
// qid is not supported
if (col.startsWith("qid:")) continue;
// actual value
index = Integer.parseInt(col.substring(0, col.indexOf(":")));
if (index > max) max = index;
}
// read values into array
tok = new StringTokenizer(val, " \t");
// 1. class
double classVal = Double.parseDouble(tok.nextToken());
int numRecordsAdded = 0;
// 2. attributes
while (tok.hasMoreTokens()) {
col = tok.nextToken();
// finished?
if (col.startsWith("#")) break;
// qid is not supported
if (col.startsWith("qid:")) continue;
// actual value
index = Integer.parseInt(col.substring(0, col.indexOf(":")));
if (index > numRecordsAdded) {
int totalDiff = Math.abs(numRecordsAdded - index);
for (int i = numRecordsAdded; i < index; i++) {
ret.add(new DoubleWritable(0.0));
}
numRecordsAdded += totalDiff;
}
value = Double.parseDouble(col.substring(col.indexOf(":") + 1));
ret.add(new DoubleWritable(value));
numRecordsAdded++;
}
if (numAttributes >= 1 && ret.size() < numAttributes) {
int totalDiff = Math.abs(ret.size() - numAttributes);
for (int i = 0; i < totalDiff; i++) {
ret.add(new DoubleWritable(0.0));
}
}
ret.add(new DoubleWritable(classVal));
} catch (Exception e) {
log.error("Error parsing line '" + val + "': ", e);
}
return ret;
}
