The commands you propose works because you set/changed environment
variables (PATH, JAVA_HOME). But for every other user (including system
users) these normally do not work (you could say that there is
/etc/environment but there is no policy forcing a program to use it).
In general, one reason why
I disagree with the following statement:
"It seems that you have installed your JDK to /opt/jdk manually.
Therefore it cannot and should not be detected by the package manager."
There are a number of ways to detect whether or not Java is available.
The easiest is:
echo $(java -version)
Others i
pdftk does not use the installed java runtime directly by calling
'java', but links binary to the CNI (Cygnus Native Interface for
C++/Java Integration) which comes only with libgcj.
Some of the packages which pdftk seems to depend on are only (indirect)
recommends/suggestions from other packages.
There are some cases where other Java library dependencies exist (such
as Apache's Commons Logging). Installing these through a package manager
can introduce version conflicts. For example, if one program depends on
part of the logging API that was removed, then upgrading breaks older
programs.
Th
