java - Instance isn't passsing given variables to class

Question

first of all; Thanks for reading and helping me out, I'm new to Java I ran into a problem.

I've made instance variables inside a particular class. After this I create a new instance/object of this class and specify the new input of the variable. The problem is: when I run the code and try if its working, it isnt working. It appears that the new variable is not passed to the class being instantiated. (When I left click the emerald block an empty string appears)

What I've already tried:

• creating a setter method to set the variable.
• using a constructor

Class that I want to make an instance of:

package rico.polkadot;

import org.bukkit.Material;
import org.bukkit.block.Block;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.block.Action;
import org.bukkit.event.player.PlayerInteractEvent;

public class InstanceClass implements Listener {
    
    public String name;     
    
    @EventHandler
    public void onInteract(PlayerInteractEvent e) {
        
        Action action = e.getAction();
        Player p = e.getPlayer();
        Block b = e.getClickedBlock();
        
        if(action.equals(Action.LEFT_CLICK_BLOCK)) {
            if(b.getType().equals(Material.EMERALD_BLOCK)) {
                p.sendMessage(name);
            }
        }
    }
}

Main class:

package rico.polkadot;

import java.util.List;

import org.bukkit.plugin.java.JavaPlugin;

public class Main extends JavaPlugin {
    
    @Override
    public void onEnable() {
        getServer().getPluginManager().registerEvents(new InstanceClass(this),this);
        InstanceClass test = new InstanceClass();{
            test.name = "lol";
        }
    }
}

question from:https://stackoverflow.com/questions/66064936/instance-isnt-passsing-given-variables-to-class

Answer 1

Ok, you should make a constructor or at least setter in your InstanceClass - best option:

public class InstanceClass implements Listener {

    public String name;

    public InstanceClass(String name) {
        this.name = name;
    }
}

Then you are asking about instance. You created one inside your onEnable() function, but you have to remember, it is not accessible outside of this function, so you can't just access this test variable from your InstanceClass.

@Override
public void onEnable() {
    // here you create instance of InstanceClass
    InstanceClass test = new InstanceClass("lol");
}