Problem whit inventory

Hi, I'm going to create an plugin that introduces missions.
I've create this:

Code:java

public boolean onCommand(CommandSender sender, Command cmd, String commandlabel, String[] args){
    Player player = (Player)sender;
    if(cmd.getName().equalsIgnoreCase("m-miniera")){
            if(player.getInventory().contains(new ItemStack(Material.COBBLESTONE, 80))){
                player.getInventory().addItem(new ItemStack(Material.DIAMOND, 1));
            }
      }
    return false;
  }

If player has 80 cobblestone, it receive 1 diamond using m-miniera. But, it doesn't works.. Where is the problem?

 

First of all, you're casting sender to player without checking if the sender is a player.
Secondly, there is no such thing as a stack of 80 cobblestone, hence the inventory will never contain it. You should check if the total contents of the inventory contains a total value of 80 cobblestone.

 

XFarwar As TheMcScavenger said, you'll need to do something like looping through the players inventory, counting how many cobblestone the player has, store it in a variable, or some sort of storing component, and check if that component is greater or equal to 80.

 

How can i define how many cobblestone need for get diamond? I would that player get a diamond if has 80 piece of cobblestone..

Help me please.

EDIT by Moderator: merged posts, please use the edit button instead of double posting.