Need a queue added to server uploading

Hi, At my alternative android marketplace we have an issue with people uploading porn and viruses. So i want to be able to go into this queue page and accept or deny uploads. All the systems already intact and working it just uploads straight to server i want it to be caught in the middle for manual acceptance in some sort of list. The server is deployed in a .war file. and is mostly gwt i believe. I'm not exactly positive what gwt uses for coding i'm guessing java and some ajax. so please be experienced with gwt.