Hashmaps in different classes

Hi! I know it's a stupid question but how do use hashmaps in different classes?

 

Make the hashmap static (static HashMap<String, Integer> <-- like that) then use classname.hashmapname to access it

 

@finalblade1234 ok so i did this : public static HashMap<UUID, Boolean> live = new HashMap<UUID,Boolean>(); and then did in the other class SpecMain.live; but it did work :/

 

@RoBaMe
Remember to put a method after .live,
example: SpecMain.live.put(player.getUUID(), true);

 

No. You shouldn't use static just because it makes Objects easily accessible. It is not how it should be used.

@RoBaMe use "Getters" to obtain Objects from different classes. As long as you have a instance of the class available, you can get anything from inside the class using getters.
If you are having trouble understanding what I mean, just google it. This is the kind of thing you should have already learned before trying to write a Bukkit plugin.

 

@teej107 I don't use static objects, but what is it that makes them bad?

 

They aren't bad. Many people just abuse them and don't know how they should be used. I have more of an explanation here: http://bukkit.org/threads/static-object-of-main-class.338854/#post-3001984

 

@teej107 So then would it be okay to use a static map to store info like the currently selected color of a player (Map<UUID, Color>) That can be accessed by all the classes that need to grab their color. Or do I really have to save an instance of the whole class and access it through methods?

 

@567legodude

It's not hard to pass info around through parameters.

 

@567legodude
A static variable is assigned to the class instead of an instance of the class, which is why some people use them for easy access to stuff.
http://stackoverflow.com/questions/7026507/why-are-static-variables-considered-evil
http://stackoverflow.com/questions/2671496/java-when-to-use-static-methods

 

@teej107 @Hawktasard I mean in a class made to store only one thing. I only need one instance of the map, which is why I was wondering if making it static was okay in that situation.

Usually when I set up a class system, I have a main class to store all the instances, and each class uses the main class to reference the other classes.

I can see why you don't want to use static if you need multiple instances of a class, but if I just need a single instance of the map, then would that be an appropriate place to use static?

 

@567legodude Kind of: http://bukkit.org/threads/static-object-of-main-class.338854/#post-3001989

 

Here's a better thought: what's preventing you from not using static?

 

@1Rogue Nothing, I did that as a test, and it worked perfectly fine. Easily able to keep a map of data.

 

Well then there's your answer, you don't need static.