Spawn SplashPotion on Player

PotionCommand.java

public final class PotionCommand implements CommandExecutor {

  @Override
  public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
    if (sender instanceof Player) {
      final Player PLAYER = ((Player) sender).getPlayer();
      final World WORLD = PLAYER.getWorld();

      // Give player the Splash Potion.
      // PLAYER.getInventory().addItem(makeSplashPotionItemStack(PotionType.INSTANT_HEAL, false, true));
      
      final ThrownPotion THROWABLE = (ThrownPotion) WORLD.spawnEntity(PLAYER.getLocation(), EntityType.SPLASH_POTION);

      THROWABLE.setItem(makeSplashPotionItemStack(PotionType.INSTANT_HEAL, false, true));

      return true;
    }

    return false;
  }

  /**
   * Make a {@link ItemStack} of {@link Material#SPLASH_POTION}
   * @param potionType {@link PotionType}
   * @param extended {@link Boolean} Should the potion be extended?
   * @param upgraded {@link Boolean} Should the potion be upgraded?
   * @return {@link ItemStack}
   */
  private ItemStack makeSplashPotionItemStack(final PotionType potionType, final boolean extended, final boolean upgraded) {
    final ItemStack POTION = new ItemStack(Material.SPLASH_POTION, 1);
    final PotionMeta META = (PotionMeta) POTION.getItemMeta();
    META.setBasePotionData(new PotionData(potionType, extended, upgraded));
    POTION.setItemMeta(META);

    return POTION;
  }

}