Fun with Java and Tomcat

So we're mucking around with our homeschooling website, and already I've encountered the potential need to hack together some modules.

I have, on hand, one almost graduated software engineer who is willing to assist, which is great because I suck at anything that has anything to do with programming or scripting beyond layout tweaking. The problem is, the almost graduated software engineer in question isn't particularly interested in picking up php. He's good at java, and has told me that he can achieve the things we want done using java and Tomcat (whatever the latter one is besides a male feline).

So...I was wondering. How hard would it be to implement java tomcat application applet thingamies (so bad with terminology, hopefully someone will vaguely comprehend that sentence) into Drupal? Or at least maybe use php to pull information out of them? I'm guessing I would have to do some fun things with custom modules to be able to either integrate or pull the data. Which I'm hoping is easier than trying to write my own things in php considering it takes me way too long to wrap my brain around this kind of stuff.

Examples of what we want done:

In the user profile forms (which I really want to tweak the layout of, might have to give this CCK thing a go) there is a section for how many kids a user has. There are three fields associated with the kids, a name, a birthdate and a gender. I have a field called "Number of kids" in which I want the user to type how many kids they have (oddly. Say 3). User types the number in, and three sets of kid associated fields come up in a nice grid assuming I can manage something like that:

--------------- name birthdate gender
1st child:
2nd child:
3rd child:

They fill in the fields, hit the submit button, done. Then I need to do some fun calculations on the birthdates so it works out how old the kids are and spits out the relevant number, and works it out in months is the kid is under 1, and then dumps the information on the user profile (hah! Something i can do!) like:

7 year old son Michael
4 year old daughter Eve
11 month old daughter Briana

Then to make things even more fun, there's going to be a record keeping thing on the site. I'm not too worried about data storage coz the layout of the form is what's going to be the most work I think, but basically it's a form that will allow parents to record the activities and progress on projects etc of all the children at once. With the completed records they should then have the ability to filter the records by child. Clicking on a child's name in the parent's user profile should also bring up the records relevant just to that child (using the same filter pretty much).

I think that was the major stuff I needed done that I couldn't find any modules to do for me. I have been informed by the very confident almost graduated software engineer that he should be able to do the above with Java and Tomcat with relative ease. What I really need to know is, is this going to be possible to integrate with Drupal? After messing around with it for this long I'm led to believe it can do almost anything if you can't code and pretty much anything if you can. Any indication of what kind of work we'd be looking at to either do java module things or modules to pull stuff out of java applications or whatever it is we need to do would be appreciated.

thanks! :)