当我尝试将ActionListener应用于JButton更改JLabel的内容时，没有任何反应

Question

I need a way to create an ActionListener that when a JButton is pressed, it updates the content of 7 different JLabels to display the information in the form of text.

The data is retrieved from methods called from an external JAR file. The methods return ArrayList. I attempted to convert the ArrayList into a String, and tried to change the JLabel content with setText().

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import api.anAPI.THEAPINAME;


public class Controller implements ActionListener {

    private MainGUI maingui;
    private SubPanel subpanel;
    private static THEAPINAME anAPI =new THEAPINAME("XyP0D75oRCGrLE78","x47ka5jmOGaJ2zvw");
    static ArrayList<String> nameList =new ArrayList<String>();
private String names;


     public Controller(MainGUI maingui,SubPanel subpanel){

        this.maingui = maingui;
        this.SubPanel = subpanel;

        MainGUI.getSearchBtn().addActionListener(this);


        nameList.addAll(anAPI.getNames());

        for (String s: nameList){

         names+= s+"\t";
        }

    }

    public void actionPerformed(ActionEvent e) {

         SubPanel.label1.setText(names);
    //6 more Labels. 
    }

}

An additional, because I have 7 JLabels, would I need to do 7 getLabel methods? Or is there a way to get them all with just 1 method.

I am not entirely sure what I am doing incorrectly, it could be that the getMethods I used returned the wrong widget in question as the code for the GUI was not done by me but by a teammate and he had done a really poor job of making it clear for us.

UPDATE: Fixed up the GUI to make it clearer, so I think that is no longer the problem. Now I think the problem might be that I did not convert the contents of the ArrayList into a String in the way I thought.

The desired function of the code is when the JButton is clicked on, the JLabels in question are all updated to their relevant data.

addController method

public void addController(Controller controller){
        control = controller;
        jb1.addActionListener(control);

    }

Answer 1

You didn't really describe what the problem is of your current code.

You can add a method say getLabels() in SubPanel class to return all of its labels, or you can add a method setLabelText(String text) to set text for all of its labels by extending or directly modifying SubPanel class.

UPDATE

You have several very confusing parts in your code.

In your constructor, it should be this.subpanel = subpanel and then it should be maingui.getSearchBtn().addActionListener(this) , also in method actionPerformed it should be subpanel.label1.setText(names) . These might not be your problems though since you didn't say it's the code you're actually running.

Looks like that you haven't created any instance of class Controller thus the code in it never gets executed.

You need to have some code outside of you Controller class like this:

   MainGUI maingui;
   SubPanel subpanel;
   // they're somehow initialized

   Controller controller = new Controller(maingui, subpanel);