[Moving to common-user@, Bcc'ing general@] If you know where you need to have your print statements you can use AspectJ to do runtime injection of needed java code into desirable spots. You don't need to even touch the source code for that - just instrument (weave) the jar file -- Take care, Konstantin (Cos) Boudnik
On Tue, Mar 22, 2011 at 09:19, Bo Sang <sampl...@gmail.com> wrote: > Hi, guys: > > I would like to do some minor modification of Hadoop (just to insert some > print codes into particular places). And I have the following questions: > > 1. It seems there are three parts of Hadoop: common, hdfs, mapred. And they > are packed as three independent jar packages. Could I only modify one part > (eg, common) and pack a new jar package without modifying the rest two. > > 2. I have try to import the folder hadoop-0.21.0/common into eclipse as a > project. But eclipse fails to recognize it as an existing project. But if I > import folder hadoop-0.21.0 as a existing project, it works. However, I only > want to modify common part. How could I only modify common part and export > a new common jar package without modifying the rest two parts. > > -- > Best Regards! > > Sincerely > Bo Sang >