The method isDropItem() of the class BlockBreakEvent should gets whether or not the block will drop items, but always return true regardless of the resultat (e.g mining diamand_ore with a wooden_axe, aka the wrong tool,  dont drop item at all, but isDropItem() return true).

encs : a  minimal reproduction plugin that show "The block drop a item" when isDropItem() is true and "The block dont drop a item" when isDropItem() is false, and the classes i make it.