Solved Sign Commands

I am trying to make a sign that when you click it it will send the player a message.
Inside my PlayerInteractEvent i have:

Code:java

if (event.getClickedBlock().getState() instanceof Sign) {
Sign sign = (Sign) event.getClickedBlock();
if (sign.getLine(0) == "[Join]") {
player.sendMessage("Signs are not yet working!");
return;
}
}

But it gives me a NPE when ever i click anything!

 

If you didn't check if the clicked block was null, then assuming it is a block and grabbing it's state will throw an NPE.

Code:

if(event.getBlock() == null) return;

Make this above your current code.

 

1. Don't use getState() to check the type of a block. http://forums.bukkit.org/threads/common-mistakes.100544/page-4#post-1709082. Use getType() and check for Material.SIGN_POST or Material.WALL_SIGN.
2. Don't assume event.getClickedBlock() doesn't return null. An interaction with air with have null return, so either check the clicked block isn't null, or only act if event.getAction() is LEFT_CLICK_BLOCK/RIGHT_CLICK_BLOCK.
3. You can't cast event.getClickedBlock() to Sign. Cast event.getClickedBlock().getState() to Sign, after having checked the block type.
4. You can't compare Java strings with '=='. Use .equals().
5. Not made clear from your post, but ensure you're importing org.bukkit.block.Sign, and not org.bukkit.material.Sign.

 

desht TheGreenGamerHD
I tried both systems and still got a NPE.

 

Post your code.

 

desht

Code:java

@EventHandler
public void onClick(PlayerInteractEvent event) {
Player player = event.getPlayer();
if (player.getItemInHand().getType() == Material.DIAMOND) {
player.openInventory(Kit);
}
if (event.getClickedBlock().getType() == Material.WALL_SIGN) {
Sign sign = (Sign) event.getClickedBlock().getState();
if (sign.getLine(0).equals("[Join]")) {
player.sendMessage("Can not connect to the match!(Yea right)");
}
}
}

 

as desht described, try changing line 7 to this:

Code:java

if (event.getAction()==Action.RIGHT_CLICK_BLOCK &&
event.getClickedBlock().getType() == Material.WALL_SIGN)

 

remremrem
I added that,
the message now displays but whenever i click somthing it throws a NPE.

 

NPE's are annoying.
You'll need to null check the player and iteminhand and you should be good.
Something like this:

Code:java

@EventHandler
public void onClick(PlayerInteractEvent event) {
Player player = event.getPlayer();
if(player != null){
if(player.getItemInHand() != null){
if (player.getItemInHand().getType() == Material.DIAMOND) {
player.openInventory(Kit);
}
if (event.getClickedBlock().getType() == Material.WALL_SIGN) {
Sign sign = (Sign) event.getClickedBlock().getState();
if (sign.getLine(0).equals("[Join]")) {
player.sendMessage("Can not connect to the match!(Yea right)");
}
}
}
}
}

Didn't test it, but you get the idea. Also, add debug messages through each line you suspect. If you read the stacktrace, you'll also be able to tell exactly which line is giving you the NPE.
To add a debug message, it's something like:

Code:

//something to test
System.out.println("this works 1");
//next thing
System.out.println("this works 2");

Before your stacktrace, you'll see the last working thing.

 

hanahouhanah
Thanks for the advice BUT the NPE is not with the top bit of code. (Works fine)
The bit that tests for the Sign being clicked gives the NPE.

 

Code:java

if (e.getAction() == Action.RIGHT_CLICK_BLOCK) {
                Block b = e.getClickedBlock();
                if ((b.getType() == Material.SIGN_POST) || (b.getType() == Material.WALL_SIGN)) {
                    Sign s = (Sign)b.getState();
                    if (s.getLine(0).equals("[Join]")){

Try that. This is what I used in one of my older plugins.
Can you read your stacktrace and show us the exact line you're getting the NPE on?

 

hanahouhanah
Here is my current code:

Code:java

@EventHandler
public void onClick(PlayerInteractEvent event) {
Player player = event.getPlayer();
if (player.getItemInHand().getType() == Material.DIAMOND) {
player.openInventory(Kit);
}
if (event.getClickedBlock().getType() == Material.WALL_SIGN && event.getAction() == Action.RIGHT_CLICK_BLOCK) {
Sign sign = (Sign) event.getClickedBlock().getState();
if (sign.getLine(0).equals("[Join]")) {
player.sendMessage("Can not connect to the match!(Yea right)");
}
}
}

It returns a NPE when i Action.LEFT_CLICK_BLOCK on somthing that is not a sign.

 

Please paste the entire error

 

Of course it does - you're checking event.getClickedBlock().getType() before you check that the action is actually a block click and not an air click.

 

Sign s = (Sign) e.getClickedBlock().getState();

 

MercilessPvP No need.
desht So i have to check:

Code:java

if (event.getAction == Action.RIGHT_CLICK_BLOCK) {
//other code
}

EDIT: I did it, thanks Guys!