List<Block> size returning 0..

Hello, I've had some problems with this. for some reason, my removed.size() gives me 0, when I know that the explosion destroyed some blocks! any help?
The error I'm getting is

Code:

 java.lang.IllegalArgumentException: n must be positive
at java.util.Random.nextInt(Unknown Source) ~[?:1.7.0_21] 

This is the code:

Code:

    @EventHandler
    public void onEntityExplode(EntityExplodeEvent e) {
        final List<Block> removed = e.blockList();
        new BukkitRunnable() {
            public void run() {
                    Random random = new Random();
                    int choice = random.nextInt(removed.size());
                    Block block = removed.get(choice);
                    //Do stuff with block
            }
        }.runTaskTimer(this, 0L, 10L);
    }

I know that the returned list size is 0 because when I add in if(removed.size() > 0){, nothing happens

 

Cryices

Why are you running it in a timer? I would imagine that could cause your problem. Are you trying to wait until after the explosion event is done?

 

I want to slowly regen the blocks, so that's why I have the delay for each block being put back

 

I imagine that after the event is done, the blocklist is cleared. Try changing your removed List to:

Code:java

new LinkedList<Block>(e.blockList());

This creates a "defensive" copy of the list that won't be affected by the original list being cleared by Minecraft.

Keep in mind, I'm just guessing.

 

Thanks, but I don't think that'll fix the problem I'm having

 

Did you even try it

In your Runnable and at the beginning of the method, print out the size of the list. Is it 0 initially or 0 when the Runnable runs? I think a delay of 0 will cause the Runnable to run the next tick (I know calling runTask does).

 

Fail I tried both, it turns out it's not returning 0, it's just not doing anything xP it's weird though, it returns 52 each time.. I don't know why that is, there's no way it could be destroying 52 blocks

 

Cryices
Can I see your code to restore the blocks?

 

Code:

    public static void regenerate(Block block){
        final Material type = block.getType();
        final byte data = block.getData();
        final Location loc = block.getLocation();
        final int id = type.getId();
        new BukkitRunnable(){
            @Override
            public void run(){
                loc.getBlock().setTypeIdAndData(id, data, false); //Setting the block type
            }
        };
    };

I'm going to instead of saving the blocks in a list, try saving the blockstate in an arraylist..

 

Cryices

Here's another hypothesis:

Blocks are objects that are not garbage collected until they are unloaded. The type id is simply changed. You will have to copy the original type id of the block into a collection for use in your Runnable (Do it in the event listener, not in the runnable). Right now, you are just setting the block to air. Perhaps a Map of Location to Integer or something similar?

 

Cryices Superckl1
Just copy the List..

 

The_Doctor_123

The Blocks will still reference the original ones...

 

Just an update, I tried saving the BlockState to an arraylist, just incase saving the block that way wasn't working somehow, but it still didn't work :/

 

Code:java

    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
    public void onEntityExplode(EntityExplodeEvent e){
        final List<BlockState> removed = new LinkedList<BlockState>();
        for(Block block:e.blockList())
            removed.add(block.getState());
        new BukkitRunnable() {
 
            private Random random = new Random();
 
            @Override
            public void run() {
                int i = random.nextInt(removed.size());
                BlockRegen.this.regenerate(removed.get(i));
                removed.remove(i);
            }
        }.runTaskTimer(this, 1L, 10L);
    }
 
    public void regenerate(BlockState state){
        Block block = state.getLocation().getBlock();
        block.setType(state.getType());
        block.setData(state.getData().getData());
    }

Tested and working. Not sure why yours isn't.

 

Well thanks, I just will use yours, and also for future reference I'm sure you just forgot it, but make sure to cancel the runnable xD, in this case I used if(removed > 0){}else this.cancel();

 

Cryices

I wrote it in a rush. Glad I could help.

 

Sorry to ask more of this, but now I need to do a bukkitrunnable again , but a little while after the first one, I tried many different ways, but the closest I got was this, by closest I got I mean no errors, I tried to do like event.wait(time..) and Thread.sleep(time..) but neither of those work, this is the code I have now

Code:

            Bukkit.getScheduler().runTaskLater(this, (Runnable) new BukkitRunnable() {
                private Random random = new Random();
                @Override
                public void run() {
                    if(items.size() > 0){
                        int i = random.nextInt(items.size());
                        regenerate(items.get(i));
                        items.remove(i);
                    }else
                        this.cancel();
                   
                }
            }.runTaskTimer(this, 1L, 10L)
        , 1200L);
        }

suggestions on how to fix anyone?.

 

Cryices
Don't call sleep or wait on the main thread! I cringe when people do that

I'm a little confused by your question. What do you mean after the first one? Right now it looks like you are just running the first one a bit later. What exactly are you trying to do?

 

well I have that first Bukkit runnable that regens the blocks, but now I need another one, and this one is for another list, and its supposed to happen after the first runnable is over.

 

Cryices
When you call cancel in the first Runnable, schedule the next one?

 

I tried that, it wasn't pretty..there were alot of errors with the this.plugin or where "this" is, and also, it didn't work, if you really think about it, you know why

 

Cryices
I've done it before. If you are in an Runnable, do ClassName.this.object to reference objects in the enclosing class.