Java Reference
In-Depth Information
There are a few things you still need to write: the internal
push_stack
,
pop_stack
,
and
peek_stack
functions, and the database functions,
myRead
and
myWrite
. You
can copy the
equalsIsh
function straight from the
BackCmd
plugin.
Let's get started on the internal stack functions first. We want to be able to
pass in a
Location
to the push, and get a
Location
back from the peek and pop,
so use the conversion functions
locationToString
and
stringToLocation
.
Go give that a try on your own first. When you're done, come check back here
and see if it looks close to this:
private void
push_stack(Location loc) {
String
s = locationToString(loc);
location_strings.add(s);
}
private
Location peek_stack() {
if
(location_strings.isEmpty()) {
return
null;
}
String
s = location_strings.get(location_strings.size()-1);
return
stringToLocation(s);
}
private
Location pop_stack() {
Location loc = peek_stack();
location_strings.remove(location_strings.size()-1);
return
loc;
}
Make sure that much compiles, using
build.sh
as usual.
Add Save and Load to BackCmd
Now that you have a
SavedLocation
that knows how to push and pop individual
locations for a
Player
, it's time for you to add the code into
BackCmd.java
, which
will call them.
Open up
BackCmd.java
and start making the following changes:
•In
onTeleport
, delete all the code in the
else
portion of the block, and replace
it with code that creates a new
SavedLocation
and calls its
push
with the
player's location.
•In
backCommand
, get the location to teleport to by creating a new
SavedLocation
and calling its
pop
to get the latest value.
The new plugin main class should end up looking like this:
