[BlockPlaceEvent] How to get the block that was in the location before the block was placed?

So the title might not make sense, but I want to get the block that was at the Location of the block placed before the block was placed. Normally this is "Material.AIR", but if it is not I want to "event.setCancelled(true);". Because I don't want blocks to override previous blocks... Such as a normal block overriding Wheat, Fire or Grass. I am looking for a way to get the previous block or cancel out overlapping.

Thanks.

 

OHQCraft

Code:

BlockPlaceEvent event;
 
BlockState block = event.getBlockReplacedState();

Note that you cannot retrieve the original Block from the BlockPlaceEvent, as a Block is bound to the world. Once it is replaced, it no longer exists.

 

I still don't get it... Is it possible?

 

OHQCraft
It's not a problem. A BlockState object is the same as a Block object, only that method calls to a BlockState object will not affect the world in any way.

Code:java

@EventHandler
public void onBlockPlace(BlockPlaceEvent event) {
 
    Block newBlock;
    BlockState oldBlock;
 
    newBlock = event.getBlock();
    oldBlock = event.getBlockReplacedState();
 
    if(newBlock != null && oldBlock != null) {
 
        if(oldBlock.getType() != Material.AIR) {
 
            event.setCancelled(true);
        }
    }
}

 

Thanks, it worked!