If I understand correctly, you say it isnt possible to take a
screenshot with java, but I beg to differ. There is a class  added
from java  1.3 and onwards called Robot. It is in the package  java.awt
Now this class is capable of overiding low-level input such as from a
keyboard or mouse. Eg it can make the cursor jump around on the
screen >=) There is also the capability of taking a screenshot. But
you need the right permissions to create a new Robot. Check the
documentation for more info.