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Problem sending message to player


TehNoiseBomb

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I've run into a problem while developing my mod where I want to send a chat message to the player when a block receives a redstone pulse. When testing the mod, I get an error:

java.lang.NullPointerException: Exception while updating neighbours

. My code:

 

 

@Override
public void onNeighborBlockChange(World w, int x, int y, int z, Block neighbor){
     if (!w.isRemote){
          if(w.isBlockIndirectlyGettingPowered(x, y, z)){
               w.getClosestPlayer((double)x, (double)y, (double)z, 0)
                    .addChatMessage(
                         new ChatComponentText("test message"));}
     }
}

 

 

The error occurs on the .addChatMessage() line.

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You're trying to get the nearest player to the block in a radius of 0. You need to make sure that player is not null before trying to do anything because World#getClosestPlayer(double,double,double,int) can return null.

BEFORE ASKING FOR HELP READ THE EAQ!

 

I'll help if I can. Apologies if I do something obviously stupid. :D

 

If you don't know basic Java yet, go and follow these tutorials.

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OK, so I added in the check to see if the player is null or not and changed the getClosestPlayer to 5 and it works now.

 

 

@Override
public void onNeighborBlockChange(World w, int x, int y, int z, Block neighbor){
     if (!w.isRemote){
          [bold]EntityPlayer player = w.getClosestPlayer((double)x, (double)y, (double)z, 5);
          if(player!=null){[/bold]
               if(w.isBlockIndirectlyGettingPowered(x, y, z)){
                    player.addChatMessage(
                         new ChatComponentText("test message"));
            }
               }
          }
}

 

 

However for some reason the chat message is firing twice. Any ideas?

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Yea that's what I'm thinking. I tried adding in @SideOnly(Side.CLIENT) before the function but that didn't change anything.

 

That's not what @SideOnly is for.

Apparently I'm a complete and utter jerk and come to this forum just like to make fun of people, be confrontational, and make your personal life miserable.  If you think this is the case, JUST REPORT ME.  Otherwise you're just going to get reported when you reply to my posts and point it out, because odds are, I was trying to be nice.

 

Exception: If you do not understand Java, I WILL NOT HELP YOU and your thread will get locked.

 

DO NOT PM ME WITH PROBLEMS. No help will be given.

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Wrap the code in

if(!world.isRemote)

 

I have that. As a refresher:

 

 

@Override
public void onNeighborBlockChange(World w, int x, int y, int z, Block neighbor){
     if (!w.isRemote){
          EntityPlayer player = w.getClosestPlayer((double)x, (double)y, (double)z, 5);
          if(player!=null){
               if(w.isBlockIndirectlyGettingPowered(x, y, z)){
                    player.addChatComponentMessage(new ChatComponentText("test message"));
               }
          }
     }
}

 

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I have decided to go a different path with what I was trying to achieve with this. Instead of giving the player the information through a chat message, I am having the player place a sign above my mod block that automatically loads the sign with the information I want to display.

 

If you are interested in how I achieved this my code is below (sorry, I'm not formatting it this time tongue.gif):

 

@Override
    public void onNeighborChange(IBlockAccess w, int x, int y, int z, int tileX, int tileY, int tileZ){
	if(w.getBlock(x, tileY, z)==Blocks.standing_sign||w.getBlock(x, tileY, z)==Blocks.wall_sign){
		this.sign = (TileEntitySign)w.getTileEntity(x, y+1, z);
		signText();
	}
    }
//This is in it's own method because I call it from elsewhere to have the sign be updated when the information changes.
private void signText(){ 
	this.sign.signText[0]="line0";
	this.sign.signText[1]="line1";
	this.sign.signText[2]="line3";
}

@Override
public boolean canPlaceBlockAt(World w, int x, int y, int z)
    {
	if(w.getBlock(x, y+1, z).isAir(w, x, y+1, z)){
		return w.getBlock(x, y, z).isReplaceable(w, z, y, z);
	}
	else return false;
    }
[/spoiler]

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