Help a little help with ArrayList and Map

[tazerman2]

hello im try to make a code but i have stuck here

first of all i have 3 npc
flag 1
flag 2
flag 3
in flag 2 i have use to spawn something guard all is works file but
am try every time to kill Flag2 to delete or kill guard if have guard alive
my problem is i have much flag and if i kill one flag the guard from all flags is delete
i need delete guard only in killed flag
here is the code

 

in flagGuard i put all name from flag npc
and after i put all spawn from FlagGuardSpawn

	public Map<String, ArrayList<L2Spawn>> _FlagGuard = new ConcurrentHashMap<>();
	public ArrayList<L2Spawn> _FlagGuardSpawn = new ArrayList<>();
	

 

and here is the delete - doDie code

is work but kill all guard from all flags

i need kill only guard from flag name
 

			for(Entry<String, ArrayList<L2Spawn>> TpGuard : FactionData.getInstance()._FlagGuard.entrySet())
			{
				if(TpGuard.getKey().equals(getName()))
				{
					for(L2Spawn g : TpGuard.getValue())
					{
						g.getNpc().doDie(null);
					}
				}
				
				System.out.println("test " + TpGuard);
			}

 

[Kara]

19 hours ago, tazerman2 said:

tnx for info but can you explance me more like how can start use a map list and how can get from 20 list only one and delete him or kill guard? and if you can explance me how can put that flag with guard in a list

 

You basically ask me to describe/code you a whole system. 

 

Before you code something you need to think of a hierarchy, means how your code will look like.

Ex. each guard belong to a flag and maybe flags belong to a bases. So guards are children of flags and flags are children of bases. 

 

So we start from the top to the bottom, we move from the parents to the children.

 

Let's say we have a Flag class, we want upon spawn to spawn guards around it and upon delete or capture to delete guards. So basically this flag will own a List with the spawned guards.

 

So you create a ArrayList inside the flag that accepts guards as objects. 

Each instance has overriden methods such as onDie(), onSpawn(), deleteMe() e.t.c. 

In these events you must handle the guards.

 

Example:

 

@Override
public void onSpawn()
{
	super.onSpawn();
}

 

Here you should spawn and add to the list all your guards. 

I guess you know how to manage a spawn of an NPC.

 

After you do that you have a list full of guard objects that belong to this flag. 

Now you can manage onDie() method. Same way in there you do a for in your guard list to delete all guards, they will respawn again once the flag is spawned cause the onSpawn() will be called.

 

You should really do some tests and some practice before make such systems. 

You need learn over super and overriden methods, difference between map and a list, thread safety e.t.c. 

 

 

 

 

[Kara]

Your whole structure is wrong and this is java before VM was a thing.

 

First of all your code can be all in 1 line. You haven't understand what a MAP is and how to use it base on this code i just saw:

 

MAP.getOrDefault("key", Collections.emptyList()).forEach(s -> s.doDie(s));

 

But again this is not the best perspective.

The proper one is to bind the guards on the flag itself.

 

Either create a method on the FlagInstance.java you created such as:

 

public void addSpawn(final L2Spawn spawn)
{
   GUARD_SPAWN.computeIfAbsent("key", k -> new ArrayList<>()).add(spawn);
}

 

and on the @Override method doDie() of the FlagInstance.java simply kill and delete all guards. Then upon onSpawn() method of FlagInstance.java you can spawn again all guards.

 

In addition using a String as a key is not good nor the object itself. Instead use it's objectId and make sure to remove it upon object's delete. 

 

In addition (2). ArrayList is not thread safe since you write and delete. Use CopyOnWriteArrayList (even tho it's slow)

Edited March 3, 2021 by Kara

[tazerman2]

tnx for info but can you explance me more like how can start use a map list and how can get from 20 list only one and delete him or kill guard? and if you can explance me how can put that flag with guard in a list