Example - Filling a chest with loot table contents

Say we wanted to write a command that populates a chest with some loot table contents. For this example, we'll use the following command:

/giveloottable <loottable> <location>

We ensure that the location provided is a container (such as a chest or shulkerbox) and then update the contents of that container:

new CommandAPICommand("giveloottable")
    .withArguments(new LootTableArgument("loottable"))
    .withArguments(new LocationArgument("location", LocationType.BLOCK_POSITION))
    .executes((sender, args) -> {
        LootTable lootTable = (LootTable) args[0];
        Location location = (Location) args[1];

        BlockState state = location.getBlock().getState();

        // Check if the input block is a container (e.g. chest)
        if(state instanceof Container container && state instanceof Lootable lootable) {
            // Apply the loot table to the chest
            lootable.setLootTable(lootTable);
            container.update();
        }
    })
    .register();