Casting to Chest

In one part of my plugin, I have to determine whether a block someone clicks is a chest or not. Once I know it's a chest, I tried casting the block to a chest, but I keep getting an error. How can I do this?

 

Use this:

PHP:

if (block.getState() instanceof Chest) { //Verify that it's a chest

    Chest chest = (Chest) block.getState(); //Cast it
    //Now you've got a chest instance!

}


 

Ah, thanks so much! What exactly is a BlockState?

 

Its something bukkit uses internally, its the block a certain point in time. Every change you make to a block state will not happen unless you THESTATE.update()

 

Do you know how to make it so the chests are combined. Right now, the inventories for the different parts of a large chest are separate, how can I find a way to "join" them into one.

 

Try:
block.getRelative(BlockFace.EAST);
block.getRelative(BlockFace.WEST);
block.getRelative(BlockFace.SOUTH);
block.getRelative(BlockFace.NORTH);

And see which one is a chest.
Then:

Code:

ItemStack[] doublecontents = new ItemStack[chest1.getInventory().getContents().length + chest2.getInventory().getContents().length];
System.arraycopy(chest1.getInventory().getContents(), 0, doublecontents, 0, chest1.getInventory().getContents().length);
System.arraycopy(chest2.getInventory().getContents(), 0, doublecontents, chest1.getInventory().getContents().length, chest2.getInventory().getContents().length);

doublecontents should have all the items.

 

Looks good, only one problem. Say I have 10 redstone in the first half of the chest, and 10 diamond in the second half. If I use your code to get the contents and place it in another chest, how do I know if it will come out the right order (redstone first half, diamond second)?

 

@TheDuceCat
Problem. This will not be in order, ie spaces will be lost:

Code:

                      Chest chest = (Chest) block.getState();
                        Chest chest2 = (Chest) block2.getState();
                        Inventory inv = chest.getInventory();
                        Inventory inv2 = chest2.getInventory();
                        Inventory[] contents;
                        contents[0] = inv;
                        contents[1] = inv2;

Not sure if thats what you want, but it will keep both halves in one variable.

 

I don't think there is any way around this, but has two double chests next to each other, then uses the right chest on one of them to get the inventory, and then go to the other double chest and put it on the left one, it will reverse the inventories.

 

Meh, just keep track of each, there is no reason to join them unless you want to compare them.
@TheDuceCat

 

I don't want to physically "join" them, I just couldn't find a better word. I want to take the inventory from one double chest, and copy it to another one. However, if someone copies the left chest, which tags along the right chest, and then places the inventory on the right chest, the chest will be reversed.

 

People...please. General heads up, because I am tired of seeing that same code in all plugins.

Stop using 'getstate instanceof <type>'
The getState() function fires several background code to get the new object. For one, it is loading lighting information and tile entity information from the chunk. Getting this information takes some time, but it's not much.

If you are continuously using getState() to compare something, it fires this same coding every.single.damn.time, which is completely useless and a waste of CPU power.

Alternatives:
Store the data and compare that

Code:

BlockState bs = block.getState();
if (bs instanceof Sign) {
   //case
} else if (bs instanceof Chest) {
   //cast
} else if (bs instanceof Jukebox) {
   //cast
}

Compare the material type - also store here as it gets this from the chunk too

Code:

Material type = block.getType();
if (type == Material.CHEST) {
    //cast getState
} else if (type == Material.JUKEBOX) {
    //cast getstate
}

I know, it is insignificant, but the more of these plugins do this, the more impact it will have on the server performance. Some developers do this in onPlayerMove for various reasons, and this is just a bad way to do it.

 

Yeah just get the block North, East, SOuth, West and find which one is a chest.

 

I always check that the block clicked is the right one before I get the getState() and cast it.

 

Great post! My views also