How do we use an item on your hand then scarfice it on a block then drops out the item of the recipe?

no I mean like when you right click it. Theres amount to craft it. Then it throws out the item that was to be crafted.

you can get the ItemStack on the player´s hand, and them remove some items, and them set other items

How you do that

All the functions you'd need should be in EntityPlayer.inventory

Depending on how the block is implemented, this may be difficult or impossible. With some crafting blocks, such as the vanilla crafting table, the crafting is actually done by the GUI. The block itself doesn't even have an inventory (that's why any items in the grid fall on the ground when you close it).

 

You might be able to fake things by creating a Container of the appropriate type and driving it as though a player were interacting with it. The code would need to be specific to that one type of crafting block, though. I don't think there's any general way to do this.

Then awnser for this was ISidedInventory. But how do implement that?