Java Reference
In-Depth Information
The parseArgs Function
Since there are a couple of things to check for when the user types in a
command, I've split that out into its own function instead of doing it right in
the
signsCommand
function.
Notice we're using a parameter from our command function that we haven't
used before:
String[]args
. These are any arguments that the player types in with
the command in the chat window. For example, if we type in
/signs
that will be passed to
signsCommand
in the
args
array as
args[0]
;
args
will have a
length of 1. If we type
/signs set one Hello!
then
args[0]
will still be
"signs"
,
args[1]
will be
"set"
,
args[2]
will be
"one"
, and
args[3]
will be
"Hello!"
.
We know that we need at least three values in the
args
array: it will either be
"signsnewname"
or
"signssetnamesomething"
.
Remember that with arrays, you have to check that the array is long enough;
otherwise you'll get a lengthy error message from the server that ends up with
something like this:
Caused by: java.lang.ArrayIndexOutOfBoundsException: 1
at namedsigns.NamedSigns.makeSign(NamedSigns.java:26)
at namedsigns.NamedSigns.signsCommand(NamedSigns.java:47)
... 15 more
We're checking the length of the arguments ourselves. But we could also set
the "
min == 3
" part in the
@Command
annotation. That way if we don't have at
least three arguments, the system will send a nice message to the player with
our
toolTip
as a help message.
Safe in the knowledge that we have
at least
three values in the
args
array to
work with, let's see what the player actually typed in.
The “/signs new” Command
Here's the part for the
"new"
command:
// signs new sign_name
private void
makeNewSign(Player me,
String []
args) {
Location loc = me.getLocation();
loc.setX(loc.getX() + 1);
// Not right on top of player
int
y = loc.getWorld().getHighestBlockAt((
int
)loc.getX(),(
int
)loc.getZ());
