Stop the dropping of signs, saplings, etc. on block break

Hi, I'm trying to find out how to stop signs, saplings, redstone dust and a few others from dropping on the ground when the block underneath is broken. I don't know how possible this is, but I don't know where to start to determine if something had came off. I've looked at the bukkit documentation with no success.

Any suggestions?
Thanks for your time.

 

i believe it is possible by doing two actions on break block event
you use block.getRelative(BlockFace.UP)
block is my getBlock() variable.
you check it by doing
if blockabove(getType.SAPLING or so(Cant remember the name)) == block(the block the user is destroying).getRelative(BlockFace.UP) you cancel the event preventing the player from destroying the block by doing
setCanceled(true);

I'm sorry that I can't explain it very well but my head is a mess xD I have the main blueprint in my head though