[1.10.2] NPE on getRegistryName

[KeeganDeathman]

Okay, so like a good boy I switched to set and getRegistryName(), but now whenever i use the getter, I get an NPE.

Why? I set the registry name? Any help?

[Draco18s]

Post your code, we're not psychic.

[KeeganDeathman]

Here's a sample block declaration

labstuffBlocks.add(blockAcceleratorPowerInput = new BlockAcceleratorPowerInput().setRegistryName("labstuff","blockAcceleratorPowerInput").setCreativeTab(tabLabStuff));

 

And my registry code

for(Block block : labstuffBlocks)
	{
		GameRegistry.register(block, block.getRegistryName());
		GameRegistry.register(Item.getItemFromBlock(block).setRegistryName(block.getRegistryName()), block.getRegistryName());
	}

[Draco18s]

Betcha it's this part here:

Item.getItemFromBlock(block)

 

Just because you called GameRegistry.register on a block does not mean your block has an item.

[KeeganDeathman]

Interesting, that must be new.

However, it also happened in this(now since reworked) functions in a block class

@Override
public boolean isOpaqueCube(IBlockState state)
{
	if(getRegistryName().getResourcePath().contains("Glass") || getRegistryName().getResourcePath().contains("Rotor"))
		return false;
	return true;
}

[Animefan8888]

Interesting, that must be new.

However, it also happened in this(now since reworked) functions in a block class

@Override
public boolean isOpaqueCube(IBlockState state)
{
	if(getRegistryName().getResourcePath().contains("Glass") || getRegistryName().getResourcePath().contains("Rotor"))
		return false;
	return true;
}

If you are getting a NPE just run a check to see if it is != null. Though I can not see the error report to give you anymore guidance.

[Matryoshika]

If the NPE is caused by

getRegistryName()

, then either the item/block you are trying to get the registry name of, does not have a registry name, or you are trying to access the registry name before you actually do set it.

 

If the NPE is caused by the, as mentioned,

Item.getItemFromBlock(block)

, then skip that method altogether. Instead, create an

ItemBlock

using the block as the passed parameter, and then register that.

ItemBlock is instantiated just like an ItemStack.

 

 

[LexManos]

Also, DO NOT run fundemental aspects of your code based off string comparisons of registry names.

Seriously...

Set a field for the opaquenss and use that...

[jeffryfisher]

I switched to set and getRegistryName(), but now whenever i use the getter, I get an NPE.

Why?

You asked about an NPE without posting the crash report. Perhaps the forum needs a banner or sticky rules to warn against that again. As Draco says, we're not psychic.

 

Rerun your code in the debugger (setting a breakpoint ahead of the crash point). Examine the fields about to be used in the crash. See what is null. Fix it.

 

Further, since order of execution is often the cause of an NPE, we need to see whole classes, not just lines out of context. You could also put print statements in both your get and set to see which runs first (then use the debugger to examine the call stack).

 

Finally, when referring to a class's methods and fields that are not static, get into the habit of prefixing them with "this."

[shadowfacts]

Finally, when referring to a class's methods and fields that are not static, get into the habit of prefixing them with "this."

 

That's completely personal preference and doesn't have any affect on the compiled code (excepting overloaded parameters). I personally don't use

this

because I feel it's unnecessarily verbose and doesn't provide any valuable information.

[jeffryfisher]

Actually, using "this" is a good habit because it will sometimes remind you when you that you have a static vs instance conflict (at least it will have you thinking about it). Well, you might never do anything that careless, but if I revisit code after months away doing something else, I sometimes break it, and I like having Eclipse tell me so sooner rather than later.

[Draco18s]

I have an IDE that formats static in italics, so I don't have that problem.