I've opened https://issues.apache.org/jira/browse/HADOOP-4881 and attached a patch to fix this.
Tom On Fri, Dec 12, 2008 at 2:18 AM, Tarandeep Singh <[email protected]> wrote: > The example is just to illustrate how one should implement one's own > WritableComparable class and in the compreTo method, it is just showing how > it works in case of IntWritable with "value" as its member variable. > > You are right the example's code is misleading. It should have used either > timestamp or counter or both and not "value". > > -Taran > > On Thu, Dec 11, 2008 at 3:55 PM, Andy Sautins > <[email protected]>wrote: > >> >> >> I have a question regarding the Hadoop API documentation for .19. The >> question is in regard to: >> http://hadoop.apache.org/core/docs/current/api/org/apache/hadoop/io/Writ >> ableComparable.html<http://hadoop.apache.org/core/docs/current/api/org/apache/hadoop/io/WritableComparable.html>. >> The document shows the following for the compareTo >> method: >> >> >> >> public int compareTo(MyWritableComparable w) { >> >> int thisValue = this.value; >> >> int thatValue = ((IntWritable)o).value; >> >> return (thisValue < thatValue ? -1 : (thisValue==thatValue ? 0 >> : 1)); >> >> } >> >> >> >> >> >> Taking the full class example doesn't compile. What I _think_ would >> be right would be: >> >> >> >> public int compareTo(Object o) { >> >> int thisValue = this.value; >> >> int thatValue = ((MyWritableComparable)o).value; >> >> return (thisValue < thatValue ? -1 : (thisValue==thatValue ? 0 >> : 1)); >> >> } >> >> >> >> But even at that it's unclear why the compareTo function is comparing >> value ( which isn't a member of the class in the example ) and not the >> counter and timestamp variables in the class. >> >> >> >> Am I understanding this right? Is there something amiss with the >> documentation? >> >> >> >> Thanks >> >> >> >> Andy >> >> >> >> >> >> >
