@SuppressWarnings("unchecked")
@Override
public void readFields(DataInput in) throws IOException {
super.readFields(in);
// First clear the map. Otherwise we will just accumulate
// entries every time this method is called.
this.instance.clear();
// Read the number of entries in the map
int entries = in.readInt();
// Then read each key/value pair
for (int i = 0; i < entries; i++) {
Writable key = (Writable) ReflectionUtils.newInstance(getClass(in.readByte()), getConf());
key.readFields(in);
Writable value = (Writable) ReflectionUtils.newInstance(getClass(in.readByte()), getConf());
value.readFields(in);
instance.put(key, value);
}
}
@Override
public void write(DataOutput out) throws IOException {
super.write(out);
// Write out the number of entries in the map
out.writeInt(instance.size());
// Then write out each key/value pair
for (Map.Entry<Writable, Writable> e : instance.entrySet()) {
out.writeByte(getId(e.getKey().getClass()));
e.getKey().write(out);
out.writeByte(getId(e.getValue().getClass()));
e.getValue().write(out);
}
}
