For last couple of days I have been working on a web based application
for skin color
measurement as I blogged here
. The core of the application is implemented in php
as it is much easier to handle. (May be I am more comfortable with it). But the GD image library for php has limited functionality. So I had to rely on Java
for border detection
and segmentation. So I implemented part of the functionality as a servlet
running on tomcat6
|Today's latte, Apache Tomcat. (Photo credit: yukop)|
Both php and servlet had to read and write same files
. But standard configuration does not allow this as php creates files as www-data (apache user) and tomcat creates files as tomcat6 user. I searched the internet for solutions. One suggestion was to create an appropriate umask
for both which I could never completely understand. Finally I realised that the easiest solution is to make tomcat run as user www-data so that all created files will have same ownership.
I found this webpage
with detailed instructions on how to do this. I would like to add two more steps:
1. Edit /etc/init.d/tomcat6 also to add the user ID and group ID
2. chown var/cache/tomcat6 directory also.
BTW the application is hosted on my laptop
. If you want to check it out click on the banner below if you see it. You will see it only when my laptop is on.